108: Benign Epithelial Tumors, Hamartomas and Hyperplasias Flashcards
What are the hallmark histologic findings of seborrheic keratosis (SKs)?
The hallmark histologic findings of seborrheic keratosis include:
- Hyperkeratosis
- Acanthosis
- Papillomatosis
- Pseudohorn cysts
What is the Leser-Trélat sign and its clinical significance in seborrheic keratosis?
The Leser-Trélat sign refers to eruptive lesions that may indicate a sign of internal malignancy. It is most commonly associated with gastrointestinal malignancies, followed by lymphoproliferative diseases.
What are the common clinicopathologic variants of seborrheic keratosis?
The common clinicopathologic variants of seborrheic keratosis include:
Variant | Description |
|—————————-|—————————————————————————–|
| Common Seborrheic Keratosis| Verrucous stuck-on papules or plaques with acanthotic proliferation. |
| Reticulated Seborrheic Keratosis| Present as pigmented patches or thin papules with interconnected down growths. |
| Stucco Keratosis | Small white to tan keratotic papules, typically on distal extremities. |
| Melanoacanthoma | Variant of pigmented SK, may resemble melanoma, commonly on head and neck.|
| Dermatosis Papulosa Nigra | Small dark brown to black keratotic papules on malar region, neck, and chest.
What are the potential causes and risk factors associated with seborrheic keratosis?
The potential causes and risk factors associated with seborrheic keratosis include:
- Unknown cause, most are sporadic
- Family history of SKs in some cases
- Possible genetic predisposition
- Sun exposure may also contribute
What activating mutations are most frequently detected in seborrheic keratosis?
The most frequently detected activating mutations in seborrheic keratosis are:
- FGFR3
- PIK3CA
- EGFR
- HRAS
- KRAS (lower frequency)
A 55-year-old patient presents with multiple eruptive seborrheic keratoses. What underlying condition should be considered and why?
Eruptive seborrheic keratoses may indicate an internal malignancy, most commonly gastrointestinal or lymphoproliferative disease, as seen in the Leser-Trélat sign.
A patient with Fitzpatrick skin type IV presents with multiple small dark brown papules on the malar region. What is the likely diagnosis and its histological features?
The likely diagnosis is Dermatosis Papulosa Nigra. Histologically, it shows orthokeratosis, acanthosis, papillomatosis, and interconnected rete with basal layer hyperpigmentation.
What are the hallmark histologic findings of seborrheic keratosis (SKs) and their clinical significance?
The hallmark histologic findings of seborrheic keratosis include:
- Hyperkeratosis: Thickening of the outer layer of the skin.
- Acanthosis: Thickening of the stratum spinosum.
- Papillomatosis: Proliferation of the epidermis leading to a warty appearance.
- Pseudohorn cysts: Cysts that resemble horns, found within the epidermis.
These findings are significant as they help differentiate SKs from other skin lesions and indicate the benign nature of these tumors, although eruptive lesions may signal underlying malignancy (Leser-Trélat sign).
How does the presence of HPV in genital seborrheic keratosis (SKs) influence clinical management?
The presence of HPV, particularly HPV6, in genital seborrheic keratosis (SKs) suggests that these lesions may share histologic characteristics with condyloma acuminatum. This influences clinical management by necessitating:
- Careful histological examination: To differentiate between SKs and other HPV-related lesions.
- Monitoring for potential malignancy: Given the association with HPV, there may be a need for closer observation or treatment if atypical features are present.
- Patient education: Informing patients about the potential for HPV-related conditions and the importance of follow-up.
What are the clinical features and histological characteristics of reticulated seborrheic keratosis?
Reticulated seborrheic keratosis is characterized by:
-
Clinical Features:
- Presents as pigmented patches or thin papules.
-
Histological Characteristics:
- Composed of interconnected delicate down growths of pigmented basilar epithelial cells.
- Presence of horn cysts.
What is the significance of the Leser-Trélat sign in the context of seborrheic keratosis?
The Leser-Trélat sign is significant in the context of seborrheic keratosis as it indicates:
- Eruptive lesions: A sudden increase in the number of SKs, which may suggest an underlying malignancy, particularly gastrointestinal cancers.
- Clinical implications: It serves as a warning sign for clinicians to investigate potential malignancies in patients presenting with new or rapidly increasing SKs, prompting further diagnostic evaluation.
What are the common clinical features and histological findings of dermatosis papulosa nigra?
Dermatosis papulosa nigra is characterized by:
-
Clinical Features:
- Multiple small dark brown to black keratotic papules, commonly found on the malar region, neck, and upper chest.
- More prevalent in individuals with Fitzpatrick skin Type IV or greater.
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Histological Findings:
- Orthokeratosis: Normal keratinization of the epidermis.
- Acanthosis: Thickening of the epidermis.
- Papillomatosis: Proliferation of the epidermis.
- Interconnected rete with basal layer hyperpigmentation.
What are the histologic variants of Clonal Seborrheic Keratosis?
Clonal Seborrheic Keratosis is characterized by intraepithelial whorls of banal keratinocytes.
What are the clinical features of Lichen Striatus?
Lichen Striatus presents with sudden onset of flat-topped, 1- to 3-mm, pink, tan, or hypopigmented papules in a linear configuration or blaschkoid distribution, commonly unilateral, with nail changes such as longitudinal ridging and nail plate thinning.
What is the treatment for irritated Seborrheic Keratosis?
Treatment options include cryotherapy, electrodesiccation followed by curettage, or laser ablation for clearly benign lesions that are irritated or cosmetically undesirable.
What is the association of Lichen Striatus with other conditions?
Lichen Striatus is associated with Atopic Dermatitis and is commonly seen in children and adolescents aged 5 to 15 years.
What are the differential diagnoses for Lichen Striatus?
Differential diagnoses include lichen planus, psoriasis, linear porokeratosis, lichen nitidus, Darier disease, and inflammatory linear verrucous epidermal nevus (ILVEN).
What are the potential complications of treating Seborrheic Keratosis?
Complications may include scarring, pigmentary alteration, incomplete removal, and recurrence.
What is the histopathological finding in Lichen Striatus?
Histopathology shows lichenoid lymphocytic infiltrate with overlying epidermal acanthosis, dyskeratosis, hyperkeratosis, and focal parakeratosis, along with mild epidermal spongiosis and exocytosis of inflammatory cells.
What is the treatment for Clear Cell Acanthoma?
Clear Cell Acanthoma treatment typically involves surgical excision, as it is a tumor of epidermal origin.
A child presents with a sudden onset of flat-topped, pink papules in a linear configuration on the arm. What is the diagnosis and its typical course?
The diagnosis is Lichen Striatus. It is self-limiting and typically resolves within a few months to 2 years.
What are the clinical features of Polypoid Seborrheic Keratosis and how can it be differentiated from other skin lesions?
- Clinical Features: Similar to skin tags, may assume a polypoid configuration, commonly found on the neck or intertriginous areas.
- Differentiation: Requires consideration of rapid growth, atypical morphology, or unusual location for biopsy. Malignant transformation may lead to squamous cell carcinoma (SCC) in situ.
What is the significance of the Meyerson phenomenon in Irritated Seborrheic Keratosis?
- Meyerson Phenomenon: Refers to the presence of surrounding eczematous changes in irritated seborrheic keratosis.
- Clinical Implication: Indicates that the lesion may be irritated by mechanical or chemical means, leading to a dense inflammatory infiltrate, typically lymphocytic and sometimes lichenoid.
How does Lichen Striatus present clinically and what is its typical course?
- Clinical Presentation: Sudden onset of flat-topped, 1- to 3-mm, pink, tan, or hypopigmented papules in a linear configuration or blaschkoid distribution.
- Typical Course: Commonly unilateral, self-limiting within a few months to 2 years, with possible longitudinal ridging and nail plate thinning.
What are the treatment options for Clear Cell Acanthoma and what are its distinguishing characteristics?
- Distinguishing Characteristics: Clear cell acanthoma is a tumor of epidermal origin, presenting as a solitary, shiny, erythematous or orange to brown, well-demarcated papule or nodule.
- Treatment Options: Treatment is not always required; however, effective options include surgical excision or cryotherapy, depending on the lesion’s characteristics and patient preference.
What are the clinical features of Chondrodermatitis Nodularis Helicis (CNH)?
- Chronic tender nodule, most commonly on the helix of the ear in men >50 years old.
- May occur on antihelix in women.
- Small (4-6 mm), nodular, tender lesion.
- Rarely multiple lesions.
- Ulceration or scale crust are common.
- Persistent, do not typically regress spontaneously.
What is the treatment approach for Warty Dyskeratoma?
- Excision is curative.
- Skin-colored, umbilicated papule on the head or neck of middle-aged and older individuals.
What are the differential diagnoses for Chondrodermatitis Nodularis Helicis (CNH)?
- Basal Cell Carcinoma (BCC)
- Squamous Cell Carcinoma (SCC)
- Keratoacanthoma
- Warts
- Tophi
What are the histopathological features of benign epithelial tumors?
- Sharply demarcated zone of pale staining epidermal keratinocytes with psoriasiform epidermal hyperplasia and a parakeratotic scale.
- Keratinocyte pallor due to heavy cytoplasmic glycogen.
- Thinning of suprapapillary plates and sparing of adnexal epithelium.
- Mild edema in the papillary dermis with increased vessels and a mixed inflammatory infiltrate.
What are the possible associations and risk factors for Chondrodermatitis Nodularis Helicis (CNH)?
- Vascular insufficiency and local ischemia.
- Systemic microvascular disease.
- Pressure related to cell phone use.
- Presence of solar elastosis at the periphery of lesions.
- Chronic actinic damage may play a role.
A middle-aged patient presents with a shiny, erythematous papule on the lower leg that blanches with pressure. What is the diagnosis and its histological hallmark?
The diagnosis is Clear Cell Acanthoma. Histologically, it shows pale-staining keratinocytes with psoriasiform epidermal hyperplasia and parakeratotic scale.
A 60-year-old man presents with a tender nodule on the helix of his ear. What is the likely diagnosis and its histological features?
The likely diagnosis is Chondrodermatitis Nodularis Helicis. Histologically, it shows epidermal ulceration, dermal collagen degeneration, and chronic inflammatory infiltrate.
A patient presents with a tender, ulcerated nodule on the helix of the ear. What conservative treatments can be considered?
Conservative treatments include pressure-relieving devices, such as doughnut-shaped pillows, and intralesional steroids.
A patient presents with a shiny, erythematous papule on the lower leg with prominent vascular puncta on dermoscopy. What is the diagnosis and its differential diagnoses?
The diagnosis is Clear Cell Acanthoma. Differential diagnoses include eccrine poroma, pyogenic granuloma, basal cell carcinoma, squamous cell carcinoma, and lichenoid keratosis.
A patient presents with a painful, erythematous nodule on the ear. What is the diagnosis and its etiology?
The diagnosis is Chondrodermatitis Nodularis Helicis. It is caused by collagen degeneration and local ischemia, often related to pressure or vascular insufficiency.
A patient presents with a painful nodule on the helix of the ear. What is the diagnosis and its differential diagnoses?
The diagnosis is Chondrodermatitis Nodularis Helicis. Differential diagnoses include basal cell carcinoma, squamous cell carcinoma, keratoacanthoma, warts, and tophi.
A patient presents with a painful, erythematous nodule on the ear. What conservative treatments can be considered?
Conservative treatments include pressure-relieving devices, such as doughnut-shaped pillows, and intralesional steroids.
What are the clinical features of Chondrodermatitis Nodularis Helicis (CNH) and how do they differ from other similar conditions?
- Chronic tender nodule: Most commonly found on the helix of the ear in men over 50 years old.
- Size: Small, 4-6 mm, nodular, tender lesion.
- Occurrence: Rarely multiple lesions.
- Ulceration: Ulceration or scale crust are common.
- Persistence: Lesions are persistent and do not typically regress spontaneously.
Differential Diagnosis: BCC, SCC, keratoacanthoma, warts, and tophi.
How does the treatment approach for Warty Dyskeratoma differ from that of Chondrodermatitis Nodularis Helicis (CNH)?
-
Warty Dyskeratoma Treatment:
- Excision is curative.
-
Chondrodermatitis Nodularis Helicis Treatment:
- Conservative treatments include pressure-relieving devices and intralesional steroids.
What are the common features of lesions in Warty Dyskeratoma?
Multiple lesions, ulceration or scale crust, and persistence without spontaneous regression.
What is the treatment approach for Warty Dyskeratoma?
Excision is curative.
How is Chondrodermatitis Nodularis Helicis treated?
Conservative management aimed at reducing pain and improving clinical appearance, including pressure-relieving devices, intralesional steroids, laser therapy, curettage, and surgical excision if necessary.
What are the histopathological features of benign epithelial tumors?
Sharply demarcated zone of pale staining epidermal keratinocytes, psoriasiform epidermal hyperplasia, parakeratotic scale, keratinocyte pallor due to heavy cytoplasmic glycogen, thinning of suprapapillary plates, and mild edema in the papillary dermis.
What is the clinical appearance of benign epithelial tumors?
Shiny, erythematous to brown papules or nodules that blanch with pressure, commonly found on the lower legs and trunk.
What are the characteristics of Acanthoma Fissuratum?
Fissured or ulcerated, firm, flesh-colored nodule, usually retroauricular, associated with areas of friction, especially with ill-fitting eyeglasses.
What histological features are seen in Acanthoma Fissuratum?
Hyperepidermal hyperplasia, hypergranulosis, vascular telangiectasia, mild fibrosis, and chronic inflammatory cell infiltrate.
What is the epidemiology of Keratinocytic Epidermal Nevus?
Most common variant of epidermal nevi, occurring in 1 in 1000 live births, without sexual predilection, mostly sporadic but can be familial.
What are the clinical features of Keratinocytic Epidermal Nevus?
Skin-colored to hyperpigmented verrucous or velvety papules that coalesce to form plaques in a blaschkoid distribution, commonly found on the neck, trunk, and extremities.
What are the etiological factors associated with Keratinocytic Epidermal Nevus?
Derived from pluripotent cells in the basal layer of the embryonic epidermis, predominantly affecting keratinocytes, leading to overgrowth of the papillary dermis.
What genetic mutations are associated with Keratinocytic Epidermal Nevus?
40% harbor RAS mutations (usually HRAS), 40% have FGFR3 or PIK3CA mutations, and 10% have mutations in KRT1 or KRT10.
What is the diagnosis for a newborn with linear, hyperpigmented verrucous plaques on the trunk?
Keratinocytic Epidermal Nevus, caused by postzygotic activating mutations, commonly in HRAS, FGFR3, or PIK3CA genes.
What is the diagnosis for a patient with a linear, verrucous plaque on the trunk?
Keratinocytic Epidermal Nevus, associated with genetic mutations including HRAS, FGFR3, PIK3CA, and occasionally KRT1 or KRT10.
What are the clinical features of keratinocytic epidermal nevi?
Skin-colored to hyperpigmented verrucous or velvety papules that coalesce to form plaques in a blaschkoid distribution, commonly found on the neck, trunk, and extremities.
What is the etiology and pathogenesis of keratinocytic epidermal nevi?
Derived from pluripotent cells in the basal layer of the embryonic epidermis, leading to overgrowth of the papillary dermis due to cutaneous mosaicism.
What are the anomalies associated with epidermal nevus syndromes?
Epidermal nevi are associated with extracutaneous anomalies, indicating a more complex developmental issue.
How does the presentation of inflammatory linear verrucous epidermal nevus (ILVEN) differ from typical keratinocytic epidermal nevi?
ILVEN presents as erythematous with thick scale, resembling psoriasis, and can be very pruritic.
What are the histopathological features of epidermolytic hyperkeratosis?
Marked orthokeratosis with vacuolization and coarse keratohyalin granule deposition within the granular layer.
What is the most definitive treatment for epidermal nevi?
Full-thickness surgical excision.
What are the clinical features of nevus sebaceous?
Hairless, yellow, waxy, and verrucous plaques following a blaschkoid pattern, becoming more elevated and verrucous under hormonal influences of puberty.
What is the epidemiology of nevus sebaceous?
Occurs in 0.1% to 0.3% of live births with equal male-female prevalence, typically sporadic but familial cases are reported.
What are the differential diagnoses for ILVEN?
Seborrheic Keratosis, Verruca, Linear and whorled nevoid hypermelanosis, Nevus sebaceous, and Lichen striatus.
What is the diagnosis for a patient with a waxy, yellow, hairless plaque on the scalp?
Nevus Sebaceous, which carries a 25% risk of developing benign or malignant neoplasms.
What is the diagnosis for a patient with a linear, erythematous plaque with thick scale on the leg?
Inflammatory Linear Verrucous Epidermal Nevus (ILVEN), with treatment options including topical steroids, retinoids, or calcipotriene.
What are the histological features of Inflammatory Linear Verrucous Epidermal Nevus (ILVEN)?
Psoriasiform epidermal hyperplasia and alternating bands of ortho- and parakeratosis.
What is the diagnosis for a patient with a linear, verrucous plaque on the trunk?
Keratinocytic Epidermal Nevus, histologically showing acanthosis, papillomatosis, and hyperkeratosis.
What are the key histopathological features of epidermolytic hyperkeratosis in ILVEN?
Chronic dermal inflammatory infiltrate, psoriasiform epidermal hyperplasia, and alternating bands of ortho- and parakeratosis.
How does the clinical presentation of Nevus Sebaceous differ from ILVEN?
Nevus Sebaceous presents with hairless, yellow, waxy plaques, while ILVEN presents with linear morphology and verrucous texture.
What are the potential complications associated with congenital epidermal nevi?
Maceration and secondary infection, malignancies such as BCC or SCC, and risk of having a child with epidermolytic ichthyosis.
What is the most definitive treatment option for epidermal nevi?
Full-thickness surgical excision, with alternative treatments including laser ablation, electrofulguration, cryotherapy, and chemical peels.
What are the histopathological features of nevus sebaceous?
Epidermal hyperplasia, immature and vellus hair follicles, ectopic apocrine glands, and sebaceous glands in the superficial dermis.
What are the common differential diagnoses for nevus sebaceous?
Epidermal nevi, syringocystadenoma papilliferum, seborrheic keratosis, and juvenile xanthogranuloma.
What are the potential complications associated with nevus sebaceous after puberty?
Thickening and verrucous changes, with a 25% risk of benign or malignant neoplasms.
What is the definitive treatment for nevus sebaceous?
Full-thickness surgical excision if there are cosmetic or psychosocial concerns.
What are the clinical features of nevus comedonicus?
Localized plaques of comedonal acne at birth or early childhood, commonly on the face, chest, or upper arms.
What is the etiology and pathogenesis of nevus comedonicus?
Potential defect in NEK9 kinase, a regulator of follicular homeostasis.
What are the differential diagnoses for nevus comedonicus?
Acne vulgaris, milia, acne neonatorum, nevus sebaceous, and linear Darier disease.
What complications may arise from nevus comedonicus?
Persistent lesions, inflammatory acne cysts leading to scarring, and extremely rare malignant transformation.
What is the diagnosis for a patient with localized plaques of comedonal acne on the chest?
Nevus Comedonicus, histologically showing keratin-filled epidermal invaginations.
What is the recommended management for a rapidly growing nodule within a nevus sebaceous?
Biopsy or excision to rule out malignant transformation.
What is the diagnosis for a patient with a yellow, waxy plaque on the scalp?
Nevus Sebaceous, histologically showing epidermal hyperplasia and sebaceous glands.
What is the risk of malignancy in nevus sebaceous?
There is a 25% risk of developing benign or malignant neoplasms.
What is the recommended management for a yellow, waxy plaque on the scalp?
The recommended management is biopsy or excision to rule out malignant transformation, such as basal cell carcinoma.
What is the diagnosis for a yellow, waxy plaque on the scalp that has thickened after puberty?
The diagnosis is Nevus Sebaceous. Histologically, it shows epidermal hyperplasia, immature hair follicles, and sebaceous glands in the superficial dermis.
What is the risk of malignancy in nevus sebaceous?
The risk of developing basal cell carcinoma within a nevus sebaceous is approximately 1%.
What are the potential complications associated with nevus sebaceous after puberty?
After puberty, nevus sebaceous can become more thickened and verrucous due to hormonal influences. Approximately 25% of individuals will develop benign or malignant (or both) secondary neoplasms within their nevus sebaceous.
What is the definitive treatment for nevus sebaceous when there are cosmetic or psychosocial concerns?
The definitive treatment for nevus sebaceous, when there are cosmetic or psychosocial concerns, is full-thickness surgical excision.
Describe the clinical features of nevus comedonicus.
Nevus comedonicus presents as localized plaques of comedonal acne at birth or early childhood, often in a clustered or linear distribution. It commonly occurs on the face, chest, or upper arms.
What are the potential complications of nevus comedonicus?
The noninflammatory variant is usually asymptomatic, while the inflammatory form can result in significant suppuration and pain. Complications may include the development of inflammatory acne cysts and scarring.
What is the hallmark histologic finding associated with nevus comedonicus?
The hallmark histologic finding associated with nevus comedonicus is keratin-filled epidermal invaginations in association with atrophic sebaceous glands or follicles.
What is the role of NEK9 kinase in the etiology of nevus comedonicus?
NEK9 kinase is postulated to be a potential regulator of follicular homeostasis, and it is believed to be defective in nevus comedonicus, contributing to its pathogenesis.
What is the primary treatment for epidermal nevi syndrome when it is cosmetically bothersome or symptomatic?
The primary treatment is reserved for cosmetic or symptomatic relief, with options including emollients, keratolytics, topical steroids, and topical retinoids.
What are the characteristics of Becker nevus syndrome?
Becker nevus syndrome is characterized by a segmental smooth muscle hamartoma associated with musculoskeletal defects, such as ipsilateral breast hypoplasia.
What is Angora hair nevus syndrome and its associated features?
Angora hair nevus syndrome consists of an epidermal hamartoma with long, fine white hair, in addition to ocular, neurologic, and skeletal deficiencies.
What is the recommended approach for the diagnosis and management of epidermal nevus syndrome?
A multi-disciplinary approach is required, involving a dermatologist, pediatrician, ophthalmologist, neurologist, plastic surgeon, and orthopedic services.
What specific syndrome is associated with ipsilateral breast hypoplasia?
This is Becker Nevus Syndrome, characterized by a segmental smooth muscle hamartoma.
What are the treatment options for epidermal nevi and their effectiveness?
Treatment options include emollients, keratolytics, topical steroids for mild improvement; topical retinoids show limited efficacy; oral retinoids or destructive modalities have limited efficacy; laser resurfacing shows best results; full-thickness surgical excision is considered definitive treatment.
What are the key characteristics of Becker nevus syndrome?
Becker nevus syndrome is characterized by a segmental smooth muscle hamartoma and associated with musculoskeletal defects, such as ipsilateral breast hypoplasia.
What is the recommended approach for managing epidermal nevus syndrome?
Management requires a multi-disciplinary approach involving a dermatologist, pediatrician, ophthalmologist, neurologist, plastic surgeon, and orthopedic services.
What are epidermoid cysts and how do they form?
Epidermoid cysts, also known as follicular cysts or keratin cysts, result from plugged pilosebaceous units and are lined by epithelium resembling the infundibulum of hair follicles.
What are the clinical features of epidermoid cysts?
Epidermoid cysts present as dermal or subcutaneous mobile nodules with a central punctum. Common sites include the upper chest, upper back, neck, and head.
What is the epidemiology of epidermoid cysts?
Epidermoid cysts are most commonly found in adults, affecting both men and women. Certain genetic disorders may predispose individuals to develop these cysts.
What are the differential diagnoses for epidermoid cysts?
Differential diagnoses include steatocystomas, which usually express a liquid rather than cheesy material; pilar cysts, which are commonly found on the scalp; and lipomas, which are softer and deeper, lacking a punctum.
What is the recommended treatment for epidermoid cysts?
The definitive treatment is complete excision or destruction of the cyst lining to prevent recurrence. Incision and drainage should be performed if the cyst is inflamed, painful, or purulent.
What is the diagnosis for a dermal nodule on the upper back that expresses foul-smelling cheesy debris?
The diagnosis is Epidermoid Cyst. Definitive treatment involves complete excision or destruction of the cyst lining to prevent recurrence.
What microbes are commonly associated with infection in epidermoid cysts?
Common microbes include Staphylococcus aureus, group A streptococcus, Escherichia coli, Peptostreptococcus spp., and Bacteroides spp.
What are the clinical features of epidermoid cysts?
Epidermoid cysts present as dermal or subcutaneous mobile nodules with a central punctum, and they are slow-growing and asymptomatic.
What is the etiology and pathogenesis of epidermoid cysts?
Epidermoid cysts result from plugged pilosebaceous units and do not involve sebaceous glands. They can occur on non-hair-bearing sites due to traumatic implantation of epidermal cells.
What are the clinical features of a trichilemmal cyst (pilar cyst)?
Trichilemmal cysts are mobile, firm, well-circumscribed nodules located in the scalp, face, head, and neck. They can rupture and become infected.
What is the epidemiology of trichilemmal cysts?
Trichilemmal cysts are found in 5% to 10% of the population and are more common in middle-aged women.
What is the histopathology of trichilemmal cysts?
Trichilemmal cysts arise from the outer root sheath of the hair follicle and lack a granular layer, containing eosinophilic keratin.
What are the clinical features of milia?
Milia are 1 to 2 mm, white, domed papules commonly on the cheeks and eyelids of adults, and can occur in infants on the face and mucosa.
What is the treatment for congenital and acquired milia?
Congenital milia typically resolve spontaneously, while acquired milia can resolve spontaneously or be removed by disrupting the overlying epidermis.
What are the clinical features of steatocystoma?
Steatocystoma presents as asymptomatic, yellow or skin-colored dermal papules or cysts, commonly found on the trunk, upper arms, scrotum, or chest.
What is the diagnosis for multiple firm, mobile nodules on the scalp?
The diagnosis is Trichilemmal (Pilar) Cyst. Histologically, it shows squamous epithelium without a granular layer and eosinophilic keratin contents.
What is the diagnosis for multiple small, white, domed papules on the cheeks?
The diagnosis is Milia. Treatment involves disrupting the overlying epidermis with light electrodesiccation or incision followed by expression of keratin contents.
What is the diagnosis for a dermal nodule on the scalp that ruptured and became infected?
The diagnosis is Trichilemmal (Pilar) Cyst. Treatment involves excision, and if inflamed, incision and drainage followed by antibiotics.
What are the clinical features of a trichilemmal cyst and what does rapid growth indicate?
Trichilemmal cysts are mobile, firm, well-circumscribed nodules. Rapid growth is abnormal and may indicate infection or malignant transformation.
How does the histopathology of a trichilemmal cyst differ from that of an epidermoid cyst?
Trichilemmal cysts arise from the outer root sheath of hair follicles and lack a granular layer, while epidermoid cysts typically have a more adherent cyst wall.
What are the treatment options for acquired milia and how do they differ from congenital milia?
Congenital milia typically resolve spontaneously, while acquired milia may require intervention such as disruption of the overlying epidermis.
What are the clinical features of steatocystoma and what complications can arise from it?
Steatocystoma presents as asymptomatic, yellow or skin-colored dermal papules or cysts. It can become infected, leading to sinus formation and scarring.
What interventions are required for certain skin conditions?
Interventions may include disruption of the overlying epidermis with light electrodesiccation or incision followed by expression of keratin contents.
What are the clinical features of steatocystoma?
Asymptomatic, yellow or skin-colored dermal papules or cysts, commonly found on the trunk, upper arms, scrotum, or chest. Oily material is expressed when incised. Can become infected, leading to suppuration, sinus formation, and scarring.
What is the etiology and pathogenesis of milia?
Milia arise from pilosebaceous or eccrine sweat duct plugging. Primary milia occur without any underlying condition, while secondary milia result from injury to the basement membrane of the skin.
What are the clinical features of dermoid cysts?
Smooth, can occur in the midline, commonly with a deep sinus tract connecting to the epidermis. Size: 1 - 4 cm, commonly located on the forehead, lateral eye, or neck. Can be located deep in the subcutaneous tissue, intracranially, or intraorbitally. Complications include infections, rupture, and abscess formation from manipulation.
What is the differential diagnosis for eruptive vellus hair cysts?
Eruptive vellus hair cysts can mimic steatocystoma multiplex and may have a tuft of hairs protruding from the cyst centrally. Other differential diagnoses include epidermal inclusion cysts and steatocystoma.
What is the treatment for branchial cysts?
Imaging studies that help characterize the extent of the tumor are necessary before excision. Surgical options may include neurosurgery, otolaryngology, or plastic surgery as indicated.
What are the histopathological features of branchial cysts?
Lined with epithelium containing a lymphocytic infiltrate and lymphoid follicles are common. If mucous glands are present in the walls, cyst contents are often mucinous.
What are the clinical features of branchial cleft cysts?
Asymptomatic, but may present after an upper respiratory infection as a painful mass. Tend to drain internally; communication with the epidermis can occur, which can be complicated by infection.
What is the diagnosis for a 26-year-old patient with yellow dermal papules on the chest?
The diagnosis is Steatocystoma Multiplex. Histologically, the cyst walls are lined by stratified squamous epithelium with sebaceous glands and keratin, oil, and hairs in the lumen.
What is the diagnosis for a child with a smooth, midline nodule on the forehead?
The diagnosis is Dermoid Cyst. Histologically, it is lined by stratified squamous epithelium and contains adnexal structures such as pilosebaceous units and eccrine glands.
How do branchial cleft cysts differ from bronchogenic cysts?
Branchial cleft cysts are located laterally along the angle of the mandible or sternocleidomastoid, while bronchogenic cysts are typically located in the mediastinum or lung area. Histologically, branchial cleft cysts have lymphoid follicles and lack smooth muscle.
What is the recommended treatment for inflamed sebaceous cysts?
Simple excision or drainage with manual removal of the cyst. For inflamed lesions, interventions may include intralesional steroids, carbon dioxide laser, oral retinoids, or cryotherapy.
What are the histopathological characteristics of dermoid cysts?
Dermoid cysts are lined by epithelium containing various appendageal structures from retained epithelium along embryonic fusion planes. Histopathology shows a central tuft of hair or communication with the epidermis.
What are the clinical features of preauricular cysts and sinuses?
Located in the preauricular area near the ascending limb of the helix. Can be unilateral or bilateral, more common on the right side.
What is the epidemiology of preauricular cysts and sinuses?
Occurs in approximately 1% of infants, with a higher incidence noted in certain African regions.
What are the treatment options for infected preauricular cysts?
Excision of the cyst is the primary treatment. Infected cysts may require incision and drainage or antibiotics.
What are the histopathological characteristics of ear pits associated with preauricular cysts?
Lined by stratified squamous epithelium and often show overlying hyperkeratosis.
What is the etiology and pathogenesis of preauricular cysts?
Congenital epithelial invaginations reflecting a local defect in embryonic fusion planes. May be an autosomal-dominant trait with variable expression.
What is the diagnosis for a patient with a painful mass along the anterior border of the sternocleidomastoid?
The diagnosis is Branchial Cyst. Histologically, it is lined with epithelium containing a lymphocytic infiltrate and lymphoid follicles.
What is the diagnosis for a newborn with a preauricular pit near the helix?
The diagnosis is Preauricular Cyst and Sinus. It may be associated with branchial cleft anomalies, hearing loss, or renal abnormalities.
What are the clinical features of preauricular cysts and sinuses related to embryonic development?
Ear pits are located in the preauricular area near the ascending limb of the helix. They can be unilateral or bilateral, more common on the right side, and are associated with congenital epithelial invaginations.
What is the significance of assessing hearing loss in patients with preauricular cysts?
Assessment for hearing loss is crucial as preauricular cysts and sinuses can be associated with branchial cleft anomalies, which may lead to hearing and renal abnormalities.
How does the epidemiology of preauricular cysts vary geographically?
Preauricular cysts occur in approximately 1% of infants and have a higher incidence in certain African regions.
It is the most common benign epidermal tumor.
Seborrheic keratosis.
These tumors usually begin as well-circumscribed tan-brown patches or thin plaques with pseudohorn cysts (keratotic invaginations).
Seborrheic keratosis
Hallmark histologic findings of seborrheic keratosis?
HAPP:
* Hyperkeratosis
* Acanthosis
* Papillomatosis
* Pseudohorn cysts
Multiple eruptive keratoses may be indicative of internal malignancy. What sign is this and what malignancy are they linked to?
Leser-Trélat sign
* GI malignancy - most common
* Lymphoproliferative disease
Location and age of predilection for seborrheic keratoses?
- Anywhere on skin except palms and soles
- Middle-aged and older adults
Stuck-on appearance
Seborrheic keratoses
Conditions with eruptive SK aside from internal malignancy?
- Erythroderma
- HIV infection
Chemotherapeutic agent that can cause inflammation of preexisting SKs? What is this sign called?
Cytarabine
Pseudo-sign of Leser-Trélat
Activating mutations in SK involve what genes?
- FGFR3
- PIK3CA
- EGFR
- HRAS
- KRAS
On histology, these epidermal tumors are composed of interconnected delicate downgrowths of pigmented basilar epithelial cells with horn cysts.
Reticulated seborrheic keratosis
Reticulated SK may arise from what lesion?
Solar lentigo
Multiple small 1 to 3 mm white to tan keratotic papules most commonly on the lower legs / distal extremities?
Stucco keratosis
Histological characteristics of stucco keratosis?
FOPA
* Fusion of rete pegs
* Orthokeratosis
* Papillomatosis
* Acanthosis
A variant of SK which is most commonly on the head, neck or trunk of an older adult and histologically presents with:
* acanthosis of basaloid and spinous keratinocytes often with horn cysts
* sporadically distributed dendritic melanocytes between keratinocytes
* melanin-laden histiocytes in the dermis
Melanoacanthoma
Location of predilection of DPN?
Malar region, neck, upper chest
Histology of DPN?
BOAPI
* basal layer hyperpigmentation
* orthokeratosis
* acanthosis
* papillomatosis
* interconnected rete
This SK variant looks like a skin tag and is found on the neck or intertriginous areas.
Polypoid SK.
Lichen striatus resolves after how long?
1-2 years.
