Rosai Chapter 3 - Tumors and Tumorlike Conditions of the Skin Flashcards
Most frequent pattern of Seborrheic Keratosis
Acanthotic pattern
Other names of Acrochordon (4):
- Fibroepithelial papilloma
- Fibroepithelial polyp
- Fibroma molle
- Skin tag
Clue to the diagnosis of Acrochordon
Absence of adnexal structures in the underlying dermis
Actinic keratosis vs. Bowen disease
-Atypical squamous cells are found in the LOWER portions of the epidermis including the basal layer
Actinic keratosis
Actinic keratosis vs. Bowen disease
-Atypical squamous cells are found in ALL portions of the epidermis but with preservation of the basal cells, which are arranged in palisades
Bowen disease
Large majority of squamous cell (epidermoid) carcinomas of the skin
Actinically induced
Incidence of SqCCA of the skin is directly related to (2)
- amount of Sun exposure to the sun
- lack of Pigmentation of the skin
Positive IHCs of SqCCA of the Skin (6)
- HMWK
- Involucrin
- EMA
- CEA
- p63
- Vimentin
Negative IHCs of SqCCA of the skin (if used to differentiate with BCCA)
- Ber-EP4
- CD10
*both positive in BCCA
Positive IHC of SqCCA of the Skin, but mostly in poorly-differentiated type
-Vimentin
Most important distinguishing features of Spindle SqCCA (3)
- Continuity of tumor cells with the basal layer of the epidermis
- Foci of clear-cut squamous change
- Positive HMWK
Most common location of Verrucous carcinoma of the skin
Sole of the foot
Best prognostic factors of SqCCA of the skin (3)
- Staging
- level of Dermal invasion
- Vertical tumor thickness
Pseudoepitheliomatous Hyperplasia vs. SqCCA
Main distinguishing features:
-Width of the Strands - Thin
Pseudoepitheliomatous Hyperplasia
Pseudoepitheliomatous Hyperplasia vs. SqCCA
Main distinguishing features:
-Degree of Keratinocytic Atypia - Lesser
Pseudoepitheliomatous Hyperplasia
Pseudoepitheliomatous Hyperplasia vs. SqCCA
Main distinguishing features:
-Width of the Strands - Broad
SqCCA
Pseudoepitheliomatous Hyperplasia vs. SqCCA
Main distinguishing features:
-Degree of Keratinocytic Atypia - Greater
SqCCA
Most frequent form of skin cancer that occurs predominantly on sun-exposed skin
Basal cell carcinoma
other name of Gorlin syndrome
Basal cell nevus syndrome
Components of Gorlin syndrome (6)
- multiple BCCA
- Palmar pits
- Calcification of dura
- Keratocysts of the jaws
- Skeletal abnormalities
- occasional abnormalities of CNS, Mesentery, and Endocrine organs
Positive IHCs of BCCA (5)
- LMWK
- CD10
- Ber-EP4
- Androgen receptors
- BCL2
Negative IHCs of BCCA (4)
- EMA
- CEA
- Involucrin
- CK20
BCCA vs. SqCCA
Positive for Ber-EP4
BCCA
BCCA vs. SqCCA
Negative for Ber-EP4
SqCCA
BCCA vs. Actinic keratosis and SqCCA
BCL2 - positive
BCCA
BCCA vs. Actinic keratosis and SqCCA
BCL2 - Negative
Actinic keratosis and SqCCA
BCCA vs. Merkel cell CA and Trichoepitheliomas
CK20 - negative
BCCA
BCCA vs. Merkel cell CA and Trichoepitheliomas
CK20 - positive
Merkel cell CA and Trichoepitheliomas
Key pathogenic event in BCCA
Dysregulation of the hedgehog pathway
Most common location of BCCA with high local recurrence (3)
- Nasolabial fold
- Inner canthus
- Postauricular region
Metastases in BCCA are more likely (3)
- Basosquamous types
- Perineurial spread
- located on sunlight-protected skin
Better predictor of local recurrence in BCCA than presence or absence of tumor at the surgical margins
Evaluation of the pattern of tumor growth
widely dispersed vs. tightly clustered nests
Main DDX of Eccrine poroma (2)
- BCCA
- Seborrheic keratosis
other name of Purely intraepidermal eccrine poroma
Hydroacanthoma simplex
other name of Purely intradermal eccrine poroma
Dermal duct tumor
other name of Hidradenoma
Eccrine acrospiroma
Mixed Tumor (Chondroid Syringoma)
IHCs for the Inner Cell layer (3)
- CK
- CEA
- EMA
Mixed Tumor (Chondroid Syringoma)
IHCs for the Outer Cell layer (6)
- Vimentin
- S100
- Actin
- Calponin
- p63
- GFAP
Vulvar vs. Perianal
Paget disease
-GCDFP-15 - Positive
Vulvar Paget disease
Vulvar vs. Perianal
Paget disease
-Hormone receptors - Positive
Vulvar Paget disease
AR > ER/PR
Vulvar vs. Perianal
Paget disease
-CK20 - Positive
Perianal Paget disease
Most common nodular lesion of the sebaceous glands
due to Hyperplasia
Positive vs. Negative
IHC of Sebaceous carcinoma
-Keratin & CK
Positive
Positive vs. Negative
IHC of Sebaceous carcinoma
-EMA
Positive
Positive vs. Negative
IHC of Sebaceous carcinoma
-Leu-in1 (CD15)
Positive
Positive vs. Negative
IHC of Sebaceous carcinoma
-AR
Positive
Positive vs. Negative
IHC of Sebaceous carcinoma
-Adipophilin
Positive
Positive vs. Negative
IHC of Sebaceous carcinoma
-CEA
Negative
Positive vs. Negative
IHC of Sebaceous carcinoma
-S100
Negative
Preferred location of inverted follicular keratosis
face of elderly patients particularly the eyelid
Most distinctive feature of inverted follicular keratosis
presence of squamous eddies
Main DDX of Trichoepithelioma
BCCA
Most helpful features of Trichoepithelioma (3)
- Frond-like arrangement of the basaloid cells
- presence of Epithelial tracts comprising two or more layers of basaloid cells
- formation of Papillary mesenchymal bodies
Main DDX of Desmoplastic Trichoepithelioma
Morphea-like form of BCCA
Trichoepithelioma vs. BCCA
CK20 - Positive
Trichoepithelioma
Trichoepithelioma vs. BCCA
BCL2 - positive at periphery
Trichoepithelioma
Trichoepithelioma vs. BCCA
Stromelysin-3 (matrix metalloproteinase) - negative
Trichoepithelioma
Trichoepithelioma vs. BCCA
CK20 - negative
BCCA
Trichoepithelioma vs. BCCA
BCL2 - diffusely positive
BCCA
Trichoepithelioma vs. BCCA
Stromelysin-3 (matrix metalloproteinase) - positive
BCCA
other name of Cowden Disease
Multiple Hamartoma syndrome
Cowden disease (5)
- Multiple Trichilemommas
- Acral Keratoses
- Sclerotic fibromas of skin
- Papillomas of the oral mucosa
- Occasionally, tumors of Breast, Thyroid, and GIT
Characteristics of Trichilemmal-type keratinization with atypical features (3)
- Brisk mitotic activity
- invasion of reticular dermis
- ulceration
Most important microscopic feature of keratoacanthoma
Architecture of the lesion as seen on cross section on LPO:
- Overhanging edges
- Keratin-filled crater
- Hemispheric shape that is buttressed by a normal-appearing epidermis
Keratoacanthomas with Numerous eruptive lesions
Grzybowki type
Keratoacanthomas with multiple ulcerating tumors with atypical distribution
Ferguson-Smith type
Epidermal/Epidermoid type vs. Pilar/Trichilemmal type Keratinous cyst
-more common (90%)
Epidermal/Epidermoid type Keratinous cyst
Epidermal/Epidermoid type vs. Pilar/Trichilemmal type Keratinous cyst
-lined by Cornified epithelium
Epidermal/Epidermoid type Keratinous cyst
Epidermal/Epidermoid type vs. Pilar/Trichilemmal type Keratinous cyst
-has distinct granular layer
Epidermal/Epidermoid type Keratinous cyst
Epidermal/Epidermoid type vs. Pilar/Trichilemmal type Keratinous cyst
-contains lamellated keratin without calcification
Epidermal/Epidermoid type Keratinous cyst
Epidermal/Epidermoid type vs. Pilar/Trichilemmal type Keratinous cyst
-preferentially on the Scalp
Pilar/Trichilemmal type Keratinous cyst
Epidermal/Epidermoid type vs. Pilar/Trichilemmal type Keratinous cyst
-Trichilemmal type Keratinization
Pilar/Trichilemmal type Keratinous cyst
Epidermal/Epidermoid type vs. Pilar/Trichilemmal type Keratinous cyst
-Keratin is not lamellated
Pilar/Trichilemmal type Keratinous cyst
Epidermal/Epidermoid type vs. Pilar/Trichilemmal type Keratinous cyst
-Some nuclei retained
Pilar/Trichilemmal type Keratinous cyst
Epidermal/Epidermoid type vs. Pilar/Trichilemmal type Keratinous cyst
-Focal calcification
Pilar/Trichilemmal type Keratinous cyst
Type of Keratinization:
-sudden keratinization without formation of granular layer and an uneven interphase between the keratinized and nonkeratinized cells
Trichilemmal type keratinization
former name of Pilomatrixoma
Calcified Epithelioma of Malherbe
Key feature of Pilomatrixoma
Basaloid cells undergo abrupt keratinization, leading to the formation of “ghost” and “shadow” cells
Key features of Malignant Pilomatrixoma/Pilomatrixoma carcinoma (2)
- Cytologic atypia
- infiltration
Ratio of melanocytes to keratinocytes in the epidermal basal layer depending on the site of the body
-1:4 to 1:10
The functional unit /epidermal-melanin unit
melanocyte + adjacent keratinocytes receiving melanin
Positive or Negative
IHC for Normal Melanocytes
-Fontana-Masson silver stain (special stain)
Positive
Positive or Negative
IHC for Normal Melanocytes
-Tyrosinase
Positive
Positive or Negative
IHC for Normal Melanocytes
-DOPA reaction
Positive
Positive or Negative
IHC for Normal Melanocytes
-S100
Positive
Positive or Negative
IHC for Normal Melanocytes
-NSE
Positive
Positive or Negative
IHC for Normal Melanocytes
-Mart-1/Melan A (A103)
Positive
Positive or Negative
IHC for Normal Melanocytes
-Microphthalmia Transcription Factor (MiTF)
Positive
Positive or Negative
IHC for Normal Melanocytes
-SOX10
Positive
Positive or Negative
IHC for Normal Melanocytes
-PAX3
Positive
Positive or Negative
IHC for Normal Melanocytes
-Vimentin
Positive
Positive or Negative
IHC for Normal Melanocytes
-Neurofilaments
Negative
Positive or Negative
IHC for Normal Melanocytes
-GFAP
Negative
Positive or Negative
IHC for Normal Melanocytes
-HMB-45
Negative
Positive or Negative
IHC for Normal Melanocytes
-Keratin
Negative
IHC Negative in Normal Melanocytes but Positive in Activated type melanocytes
HMB-45
IHC Negative in Normal Melanocytes but Positive in Neoplastic type melanocytes
Keratin
Hallmark of the melanocyte
Melanin-synthesizing organelle (melanosome)
Most common location of clusters of benign nevus cells in the capsule of lymph nodes
Axillary region
Multiple Lentigines can be seen in what syndromes? (6)
- Peutz-Jeghers syndrome
- Centrofacial lentiginosis
- Moynahan syndrome
- LEOPARD syndrome
- Carney syndrome
- Xeroderma pigmentosum
Blue nevus are sometime misdiagnosed as
Benign fibrous histiocytoma
Positive or Negative
IHCs for Blue nevus
-Melanin stains
Positive
Positive or Negative
IHCs for Blue nevus
-S100
Positive
Positive or Negative
IHCs for Blue nevus
-HMB-45
Positive
Most common locations of Cellular Blue Nevus (2)
- Buttocks
- Sacrococcygeal area
Characteristics Absent in Cellular Blue Nevus which makes it different microscopically from malignant melanoma (4)
- Junctional activity
- Epidermal invasion
- Peripheral inflammation
- Necrosis
Characteristics Present in Cellular Blue Nevus which makes it different microscopically from malignant melanoma (6)
- Pushing margins
- Biphasic pattern
- Fasciculation
- Neuroid structures
- inconspicuousness of nuclei
- relative lack of atypia and mitotic figures
Most typical presentation of Spitz nevus
-raised pink or red nodule in the skin of the face that clinically resembles a hemangioma
Features that favor a diagnosis of Spitz nevus over one of malignant melanoma (9)
- Symmetric shape
- Sharp lateral demarcation
- maturation in depth
- arrangement of the spindle cells perpendicularly to the skin surface
- presence of tadpole and multinucleated giant cells
- lack of upward epidermal spread of single melanocytes
- presence of telangiectasia, edema, and fibrosis
- presence of eosinophilic hyaline bodies along the dermoepidermal junction thought to be made of basement membrane material (Kamino bodies)
- lack of ulceration
Spitz nevus vs. Malignant melanoma
Cytoplasm - homogeneous acidophilic ground-glass appearance
Spitz Nevus
Spitz nevus vs. Malignant melanoma
Cytoplasm - more irregular in configuration and staining reaction
Malignant melanoma
Spitz nevus vs. Malignant melanoma
-Consumption of Epidermis
Malignant melanoma
Congenital nevus differs from the more common acquired variety because (4):
- generally Large size
- tendency to involve the reticular dermis and subcutaneous tissue
- single cell permeation of dermal collagen bundles
- involvement of skin adnexa, arrector pili muscles, nerves, and vessels
Characteristics of Giant Congenital Nevus (3):
- Extensive size
- Surface area - 144 cm2 or larger
- nevus > 20 cm in diameter in adult or > or = to 20% BSA
Giant cell nevus with Meningeal/cerebral melanosis
Neurocutaneous melanosis or melanocytosis
Giant cell nevus with numerous satellite nevi
Melanophakomatosis
Characteristics of Dysplastic nevus (4)
- clinically Atypical
- large size (>5 mm)
- irregular outline
- variegated appearance
Subungual region cutaneous melanomas
Melanotic whitlow
Most common form of Melanoma
Superficial spreading melanoma
other names of Superficial spreading melanoma (2)
- Premalignant melanosis
- Pagetoid melanoma
Telltale color of early superficially spreading melanoma
shade of Blue admixed with tan, brown, or dark brown
Most commonly affected region of spindle cell melanoma
Head and Neck
Differential diagnosis of Desmoplastic melanoma (4)
- Hypertrophic scar
- Atypical Fibroxanthoma
- Spindle SqCCa
- Peripheral nerve sheath tumor
Clues to the diagnosis at the H&E level of Desmoplastic melanoma (5):
- focal Fascicular pattern of growth
- Deep invasion
- Infiltration of nerves
- Lymphoid aggregates at tumor periphery
- Presence of a lesion with the features of Lentigo maligna in the overlying epidermis
Features suggestive of melanoma in H&E sections (5)
- cells with abundant acidophilic, finely granular cytoplasm
- pseudonuclear inclusions
- combination of epithelial and spindle cell patterns of growth
- fascicular arrangement of tumor cells
- Pseudoalveolar arrangement
Strong indicators that the melanoma is malignant (2)
- Atypical mitoses
- Dermal mitoses
Sign of degeneration and is a particularly useful sign of melanoma
Melanocytes with an abundant clear cytoplasm having a finely dispersed (“dusty”) chromatin
Two situations in which argentaffin stains are particularly useful in melanoma
- Detecting finely dispersed granules that are not immediately apparent in H&E sections
- Demonstrating that the brown pigment seen in the routine sections is melanin rather than hemosiderin
Key enzyme for the production of melanin from tyrosine
Tyrosinase
Common molecular genetic alteration in melanomas occurring in acral and chronic sun-damaged skin
KIT
Uncommon molecular genetic alteration in melanomas occurring in acral and chronic sun-damaged skin (2)
- BRAF
- NRAS
Best procedure for the initial evaluation of suspicious pigmented skin lesions
-Elliptical excisional biopsy with narrow margins (down to the subcutaneous fat)
Microscopically, the early stage of regression is characterized by:
-a dense infiltrate of lymphocytes
Only melanomas that have been found to undergo spontaneous regression
Melanomas with an intraepidermal component
Accurate staging procedure and a powerful prognostic indicator
Sentinel node biopsy
Sentinel node biopsy is recommended for (2)
- All melanomas measuring 1 mm or more in thickness
- thinner melanomas with dermal mitotic figures or ulceration
Histiocytes vs. Melanoma cells
-Lack nuclear atypia
Histiocytes
Histiocytes vs. Melanoma cells
IHC
-CD68/PG-M1 - positive
Histiocytes
Histiocytes vs. Melanoma cells
IHC
-SOX10 - negative
Histiocytes
Histiocytes vs. Melanoma cells
IHC
-CD68/PG-M1 - negative
Melanoma cells
Histiocytes vs. Melanoma cells
IHC
-SOX10 - positive
Melanoma cells
Treatment of choice of most malignant melanomas
Wide excision of the primary lesion
Most powerful predictors of survival in melanoma (2)
- Tumor thickness (Breslow level)
- Ulceration
Level of invasion (Clark’s level)
-Epidermis
- Level I
* Melanoma in situ
Level of invasion (Clark’s level)
-Papillary dermis
Level II
Level of invasion (Clark’s level)
-Filling the papillary dermis
Level III
Level of invasion (Clark’s level)
-Reticular dermis
Level IV
Level of invasion (Clark’s level)
-Subcutis
Level V
Breslow thickness
-<0.76 mm
Low
Breslow thickness
-5-year disease free survival - 98%
Low
Breslow thickness
-0.76-1.50 mm
Intermediate
Breslow thickness
-5-year disease free survival - in-between 63 to 98%
Intermediate
Breslow thickness
->1.5 mm
High
Breslow thickness
-5-year disease free survival - 44-63%
High
More powerful prognostic indicator than ulceration
Tumor mitotic rate
High risk sites of melanomas (8)
- Scalp
- Mandibular area
- Midline of trunk
- Upper medial thighs
- Hands
- Feet
- Popliteal fossae
- Genitalia
Melanoma with better prognosis
dense lymphocytic infiltrate around the melanoma particularly if the lymphocytes are closely intermingled with the neoplastic melanocytes (tumor-infiltrating lymphocytes)
Correlates with an increased probability of lymph node metastases
numerous plasma cells in the infiltrate
Growth of melanoma cells along the external surface of blood vessels
Angiotropism
Predictor of local recurrence and in-transit metastases
Angiotropism
Only microscopic change in Hyperpigmentation
increased pigmentation of basal melanocytes, accompanied by an increased transfer of melanin into the adjacent keratinocytes and melanophages in the dermis
Most common locations of merkel cell Ca (2)
- Face
- Extremities
Hematoxyphilic staining of vessel walls and fibrous septa
Azzopardi phenomenon
Positive vs. Negative
IHC of Merkel Cell Carcinoma
-LMW Keratin
Positive
-particularly CK20 (perinuclear dot-like)
Positive vs. Negative
IHC of Merkel Cell Carcinoma
-Neurofilaments
Positive
Positive vs. Negative
IHC of Merkel Cell Carcinoma
-NSE
Positive
Positive vs. Negative
IHC of Merkel Cell Carcinoma
-TTF-1
Negative
Most common site of fibrous papule of the face
Nose
Tuberous sclerosis (3)
- multiple fibromas of the face, scalp, and subungual region
- Angiofibroma of the face
- Shagreen patches in the lumbosacral region
Sclerotic fibroma vs. Collagenous fibroma
-“Storiform collagenoma”
Sclerotic fibroma
Sclerotic fibroma vs. Collagenous fibroma
-Heavy disposition of collagen
Sclerotic fibroma
Sclerotic fibroma vs. Collagenous fibroma
-wood-grain pattern
Sclerotic fibroma
Sclerotic fibroma vs. Collagenous fibroma
-“Desmoplastic fibroblastoma”
Collagenous fibroma
Sclerotic fibroma vs. Collagenous fibroma
-fascial involvement
Collagenous fibroma
other name of Benign Fibrous Histiocytoma (3)
- Dermatofibroma
- Histiocytoma
- Sclerosing hemangioma
Positive vs. Negative
IHCs of Dermatofibroma
-Factor XIIIa
Positive
Positive vs. Negative
IHCs of Dermatofibroma
-HMGA1/HMGA2
Positive
Positive vs. Negative
IHCs of Dermatofibroma
-CD34
Negative
Dermatofibroma vs. DFSP
-CD34 - positive
DFSP
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-Vimentin
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-Actin
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-Calponin
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-h-Caldesmon
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-CD68
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-alpha1-antitrypsin
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-alpha1-antichymotrypsin
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-Cathepsin-B
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-FXIIIa
POSITIVE
-focal
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-S100
POSITIVE
-focal
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-CD10
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-CD117
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-CD99
POSITIVE
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-Keratin
Negative
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-EMA
Negative
POSITIVE vs. NEGATIVE
IHC for Atypical Fibroxantoma
-Desmin
Negative
Important IHCs for Atypical Fibroxanthoma (2)
- focal S100
- Negative Keratin
Microscopic diagnostic characteristics of DFSP (6)
- radial whorls of spindle cells producing the storiform or cartwheel pattern
- High cellularity
- Monomorphic appearance
- Diffuse infiltration of subcutaneous fat
- Lack of foamy or Hemosiderin-laden macrophages and/or MNGC
- Lack of peripheral collagen trapping
Positive or Negative
IHC for DFSP
-Vimentin
Positive
Positive or Negative
IHC for DFSP
-Actin
Positive
*focally and inconstantly
Positive or Negative
IHC for DFSP
-CD34
Positive
*strongly and consistently
Positive or Negative
IHC for DFSP
-S100
Negative
Positive or Negative
IHC for DFSP
-HMB-45
Negative
Positive or Negative
IHC for DFSP
-Keratin
Negative
Positive or Negative
IHC for DFSP
-FXIIIa
Negative
Pleomorphic sarcomas that arise in sun-damaged skin of the Head and Neck of elderly patients
Pleomorphic dermal sarcoma
Pleomorphic dermal sarcoma vs. Atypical fibroxanthoma
-infiltrative growth pattern
Pleomorphic dermal sarcoma
*most important
Pleomorphic dermal sarcoma vs. Atypical fibroxanthoma
-necrosis
Pleomorphic dermal sarcoma
Pleomorphic dermal sarcoma vs. Atypical fibroxanthoma
-perineural invasion
Pleomorphic dermal sarcoma
Flat xanthomas of eyelid
Xanthelasma
Xanthoma in trunk or extremities of male
Papular xanthoma
Abrupt onset of crops of yellowish papules with erythematous halos on the extensor surfaces
Eruptive xanthoma
Papillomatous, verruca-like change of the overlying epidermis
Verruciform xanthoma
Most common involvement of Xanthogranuloma
upper part of the body
Positive or Negative
IHC for Xanthogranuloma
-CD68
Positive
Positive or Negative
IHC for Xanthogranuloma
-alpha1-antichymotrypsin
Positive
Positive or Negative
IHC for Xanthogranuloma
-lysozyme
Positive
Positive or Negative
IHC for Xanthogranuloma
-other histiocytic marker
Positive
Positive or Negative
IHC for Xanthogranuloma
-S100
Negative
Giant cell reticulohistiocytoma with articular involvement
lipoid dermatoarthritis
Defining nature of Langerhans cell histiocytosis
CD1a positivity
Important diagnostic sign of LCH of the skin
invasion of the epidermis by the infiltrate
Three distinct types of Leiomyomas of the skin
- Genital
- Pilar
- Solitary Angioleiomyoma
Type of skin leiomyoma
-Located in the nipple or scrotum
Genital
Type of skin leiomyoma
-multiple superficial nodules of nevoid or hamartomatous type derived from from arrectores pilorum muscle
Pilar
Type of skin leiomyoma
-with bizarre hyperchromatic nuclei
- Pilar
- Solitary Angioleiomyoma
Type of skin leiomyoma
-aka as Vascular Leiomyoma
-Solitary Angioleiomyoma
Type of skin leiomyoma
-Subcutaneous
-Solitary Angioleiomyoma
Peripheral nerve sheath tumors with predilection for cutaneous (dermal) involvement (4)
- Neurofibroma
- Granular cell tumor
- Dermal nerve sheath myxoma
- Palisaded encapsulated neuroma
other name of Dermal nerve sheath myxoma
Myxoid neurothekeoma
other name of Palisaded encapsulated neuroma
Solitary circumscribed neuroma
Most helpful positive IHC stains for Cellular Neurothekeoma (2)
- NKI/C3
- CD10
Most peculiar skin lesion characterized by a proliferation of nerve fibers coated by squamous epithelium
Epithelial sheath neuroma
Patterns of Perineurioma (4)
- Epithelioid
- Sclerosing
- Reticular
- Plexiform
Pattern of perineurioma that is often misdiagnosed as epithelioid histiocytoma
Epithelioid
Pattern of perineurioma that simulates a fibroma and is usually Acral in location
Sclerosing
Important clue to the diagnosis of Perineurioma
EMA positivity
other name of Infantile Hemangioma
Benign infantile hemangioendothelioma
other name of Hobnail Hemangioma
Targetoid hemosiderotic hemangioma
Hemangiomas of skin with hyaline globules (2)
- Glomeruloid hemangioma
- Papillary hemangioma
aka as Superficial lymphangioma of the skin
Lymphangioma circumscriptum
aka as Deep lymphangioma of the skin
Lymphangioma cavernosum
aka as Cystic lymphangioma of the skin
Cystic hygroma
Characteristics of Cutaneous intralymphatic histiocytosis (3)
- dilated vessels
- CD68 positive in histiocytes
- rheumatoid arthritis
other name of Pyogenic granuloma (2)
- granuloma pyogenicum
- lobular capillary hemangioma
Most common locations of Pyogenic granuloma (2)
- Fingers
- Lips
Most distinctive feature of Pyogenic granuloma and almost always indicator of a benign process
vascular (capillary) lobule
This feature of Pyogenic granuloma is defined as a central branching vessel surrounded by a hypercellular proliferation of newly formed endothelial and perithelial cells
vascular (capillary) lobule
other name Acquired tufted angioma
Angioblastoma
other names of Masson Hemangioma (3)
- Vegetant intravascular hemangioendothelioma
- Masson pseudoangiosarcoma
- Intravascular papillary endothelial hyperplasia
other name of Epithelioid Hemangioma (2)
- Histiocytoid hemangioma
- Angiolymphoid hyperplasia with eosinophilia
Defining feature of Epithelioid hemangioma
peculiar epithelioid or histiocytoid appearance of the endothelial cells
Most common locations of the classic form of Kaposi sarcoma (2)
- Foot
- Ankle
Most commonly involved organs of Kaposi sarcoma (2)
- Lymph nodes
- GIT
Indicators of poor outcome in classic Kaposi sarcoma (2)
- immunosuppression
- age greater than 50 yo
Most typical feature microscopically of Kaposi sarcoma
presence of spindle cells forming slits containing RBCs
Promontory sign of Kaposi sarcoma
in early lesions, spindle proliferation may be limited to the papillary dermis and to the vascular plexus with the neoplastic vessels dissecting around dermal structures such as the secretory coil of sweat glands or blood vessels
Clues to the diagnosis of Bacillary angiomatosis (2)
- clusters of neutrophils (many of them fragmented)
- presence of a granular purplish-staining extracellular material
Bacillary Angiomatosis vs. Verruga peruana
-Bartonella henselae (rickettsia-like)
Bacillary Angiomatosis
Bacillary Angiomatosis vs. Verruga peruana
-Bartonella bacilliformis
Verruga Peruana
Most important clue to the diagnosis of Verruga Peruana
Rocha-Lim inclusions
Three distinct patterns microscopically of Angiosarcoma
- Undifferentiated foci, which can simulate carcinoma or malignant melanoma
- Freely anastomosing channels lined by atypical endothelial cells, surrounding skin adnexa, and dissecting dermal collagen fibers
- areas resembling Kaposi sarcoma
Tumors notorious for their ability to simulate angiosarcoma (3)
- SqCCA
- Epithelioid sarcoma
- Pseudoangiomatous atypical fibroxanthoma
consistent features of post-radiation angiosarcoma that is not seen in atypical vascular lesion (2)
- amplification of MYC
- expression of MYC
Positive or Negative
IHC for Retiform Hemangioendothelioma
-CD31
Positive
Positive or Negative
IHC for Retiform Hemangioendothelioma
-CD34
Positive
Positive or Negative
IHC for Retiform Hemangioendothelioma
-FVIII-related antigen
Positive
Positive or Negative
IHC for Retiform Hemangioendothelioma
-D2-40 (lymph vessel marker)
Negative
Positive or Negative
IHC for Retiform Hemangioendothelioma
-VEGFR-3
Negative
other names of Cutaneous Lymphoid Hyperplasia (5)
- Lymphoplasia
- Lymphadenoma
- Lymphocytoma benigna cutis
- Lymphadenosis benigna cutis
- Spiegler-Fendt sarcoid
Histologic features that have been traditionally been used to favor a diagnosis of lymphoid hyperplasia over one of malignant lymphoma (7)
- multiplicity of cell types
- formation of lymphoid follicles
- polarized germinal centers
- tingible body macrophages
- vascular proliferations
- predominantly perivascular or periadnexal distribution of the infiltrate
- prominent epidermal hyperplasia
other clinically benign lymphocytic infiltrates that can microscopically simulate malignant lymphoma (4)
- molluscum contagiosum
- Syphilis
- Nodular scabies
- Actinic reticuloid
Most common site of involvement of Primary Cutaneous Follicle Center Lymphoma
Head and Neck
Most common cutaneous lymphoma subtype
Mycosis fungoides
Clinical signs associated with poor prognosis in Mycosis fungoides (3)
- presence of generalized plaques or tumors
- diffuse erythema
- lymphadenopathy
Sézary syndrome vs. Woringer-Kolopp disease
-variant of Mycosis fungoides
Sézary syndrome
Sézary syndrome vs. Woringer-Kolopp disease
Clinical - infiltratrive erythrodermal with pruritus
Sézary syndrome
Sézary syndrome vs. Woringer-Kolopp disease
-Lymphadenopathy
Sézary syndrome
Sézary syndrome vs. Woringer-Kolopp disease
Microscopic - presence of large or small cerebroid cells (Sezary and Lutzner cells) in the peripheral blood
Sézary syndrome
Sézary syndrome vs. Woringer-Kolopp disease
-Pagetoid Reticulosis
Woringer-Kolopp disease
Sézary syndrome vs. Woringer-Kolopp disease
Clinical - Solitary erythematosquamous patch, typically on the extremities
Woringer-Kolopp disease
Sézary syndrome vs. Woringer-Kolopp disease
-extremely slow evolution
Woringer-Kolopp disease
Sézary syndrome vs. Woringer-Kolopp disease
Microscopic - monomorphic intraepidermal infiltrate of cells with cerebroid nuclei
Woringer-Kolopp disease
Two most important diagnostic features of lymph nodes in Mycosis fungoides (2)
- preservation or distortion of the nodal architecture
- number of atypical lymphoid cells in T cell-dependent paracortical areas
Subcutaneous panniculitis-like T-cell lymphoma vs. Cutaneous gamma/delta+ T-cell lymphoma
- CD3 - pos
- CD8 - pos
- CD4 - neg
- CD56 - neg
Subcutaneous panniculitis-like T-cell lymphoma
Subcutaneous panniculitis-like T-cell lymphoma vs. Cutaneous gamma/delta+ T-cell lymphoma
-Excellent 5-year survival
Subcutaneous panniculitis-like T-cell lymphoma
Subcutaneous panniculitis-like T-cell lymphoma vs. Cutaneous gamma/delta+ T-cell lymphoma
- CD3 - pos
- CD8 - neg
- CD4 - neg
- CD56 - pos
Cutaneous gamma/delta+ T-cell lymphoma
Subcutaneous panniculitis-like T-cell lymphoma vs. Cutaneous gamma/delta+ T-cell lymphoma
-very aggressive
Cutaneous gamma/delta+ T-cell lymphoma
other name of Intravascular (Angiotropic) Lymphoma
Malignant (Systemic, Proliferative, Neoplastic) Angioendotheliomatosis
10% of Leukemia cutis with…
Monocytic leukemia
8% of Leukemia cutis with…
CLL
5% of Leukemia cutis with…
Chronic granulocytic leukemia
Hamartoma of the scalp with ectopic meningothelial elements
Rudimentary meningocele
Metaplastic synovial cyst
Synovial metaplasia of the skin
Most common source of metastatic tumor to the skin in men
Lung (25%)
Most common source of metastatic tumor to the skin in women
Breast (69%)
Cutaneous metastases of Gastric carcinoma or Primary Sweat gland carcinoma
-Antibody HIK1083 - Positive
Cutaneous metastases of Gastric carcinoma
*detects gastric o-glycan
Cutaneous metastases of Gastric carcinoma or Primary Sweat gland carcinoma
-Antibody HIK1083 - Negative
Primary Sweat gland carcinoma
Sweat gland carcinoma or Metastatic carcinoma from various sites
Podoplanin (D2-40) - Positive
Sweat gland carcinoma
Sweat gland carcinoma or Metastatic carcinoma from various sites
p63 - Positive
Sweat gland carcinoma
Sweat gland carcinoma or Metastatic carcinoma from various sites
p40 - Positive
Sweat gland carcinoma
Sweat gland carcinoma or Metastatic carcinoma from various sites
Podoplanin (D2-40) - Negative
Metastatic carcinoma from various sites
Sweat gland carcinoma or Metastatic carcinoma from various sites
p63 - Negative
Metastatic carcinoma from various sites
Sweat gland carcinoma or Metastatic carcinoma from various sites
p40 - Negative
Metastatic carcinoma from various sites
Most common sites for skin metastases (3)
- Chest
- Abdomen
- Head and Neck
