Random Dermatopathology Flashcards
Typically the walls of cryptococcal aggregates contain melanin. What stain is best for highlighting this feature?
*Image: crytococcus aggregates with gelatinous capsules.
Fontana-Masson stain
What is the differential diagnosis for neutrophils in the stratum corneum?
“PTICS”
- Psoriasis
- Tinea
- Impetigo
- Candidiasis
- Syphilis
The image below depicts Medlar bodies (“copper penny spores”). What fungus is this characteristic of?
Chromomycosis
This is crazy!
That is all.
Collagen trapping (often seen as collagen balls) is characteristic of which fibrous tumor?
Dermatofibroma
*Other features include: acanthosis, follicular induction, and ringed siderophages.
When Touton giant cells (lipid-laden histiocyte with multiple nuclei grouped around a small island of cytoplasm) contain hemosiderin, they are called ringed siderophages. These are pathognomonic of which fibrous tumor?
Dermatofibroma
An asteroid body is a collection of eosinophilic material. If an asteroid body is present, what infectious disease might you think of? What about if the asteroid body is found within a giant cell?
- Sporotrichosis
- Sarcoidosis, berylliosis, and other granulomatous diseases
What type of collagen is found within caterpillar bodies (seen in porphyria cutanea tarda)?
Type IV
A Cowdry A body is also known as a Lipshutz body. What type of infection are Cowdry bodies seen in?
Herpes virus infections
What type of infections are Cowdry B bodies seen in?
Adenovirus and poliovirus infections
In what infectious condition are Donovan bodies (intracellular organisms) seen in?
Granuloma inguinale (Donovanosis)
This term refers to lymphocytes in the epidermis with relative absence of spongiosis. This term is usually reserved for mycosis fungoides.
Epidermotropism
This term refers to the presence of lymphocytes in the epidermis with associated spongiosis. This term is typically used when referring to spongiotic dermatitis.
Exocytosis
In what two conditions are papillary mesenchymal bodies seen?
Trichoblastoma and trichoepithelioma
In what condition are verocay bodies seen?
Schwanommas
Why are the cells in clear cell acanthoms (pale cell acanthomas) pale in appearance?
Because they lack phosphorylase, which results in an accumulation of glycogen.
*Note: classically there’s an abrupt transition between the pale cells and normal cells.
Cutaneous melanoacanthomas are a type of seborrheic keratosis composed of both small cuboidal keratinocytes and pigmented dendritic melanocytes. Are oral melanoacanthomas related to seborrheic keratoses?
*Image: cutaneous melanoacanthoma.
No, they are not related. Oral melanoacanthomas are reactive proliferations unrelated to seborrheic keratoses.
What does the following image represent? Note the endophytic nature of the lesion, resembling an expanded hair follicle.
Inverted follicular keratosis
*Note: squamous eddies are often present.
The lesion below is endophytic in nature and displays acantholytic dyskeratosis. The lesion does NOT represent Darier’s disease or Hailey-Hailey (these would not be endophytic, although they tyipcally display acantholytic dyskeratosis). What is it?
A warty dyskeratoma
*Note: some warty dyskeratomas are crateriform; however, some resemble dilated hair follicles.
The lesion below is composed of bland keratinocytes. Acanthosis is also present, and the lesion closely resembles the “dilapidated brick wall” of Hailey-Hailey. What is it?
Acantholytic acanthoma
Clinically, the following lesion resembles a seborrheic keratosis. Histologically, they are crateriform and display epidermolytic hyperkeratosis (note: this is different than acantholytic dyskeratosis).
Epidermolytic acanthoma
True or false: histologically, inflammatory linear verrucous epidermal nevus (ILVEN) lesions typically have intense dermal inflammation.
False; the word “inflammatory” refers to the erythematous clinical appearance of these lesions.
*Histologically these have variable acanthosis, and a stratum corneum with alternating ortho- and parakeratosis.
Blashkoid epidermolytic hyperkeratosis resembles an epidermal nevus clinically, but histologically displays epidermolytic hyperkeratosis. How should the patient be counselled with respect to the risk for genetic inheritance in their offspring?
These lesions represent mosaic mutations in keratin 1 and 10. If the gonads are affected, the patient can pass on the mutation, and have a child with generalized epidermolytic hyperkeratosis (bullous congenital ichthyosiform erythroderma).
What two conditions has vellus hair cysts been associated with?
Renal failure and Lowe syndrome (Fanconi-type renal failure, mental retardation, and eye abnormalities)
Similar to steatocystomas, in this type of cyst there is often a red “shark-tooth” lining. Also, similar to steatocystomas, this type of cyst may have sebaceous glands in the lining. However, unlike steatocystomas, this type of cyst occurs along embryonic fusion planes and may be associated with underlying skull defects. What type of cyst is it?
Dermoid cysts
The picture below is of a proliferating pilar cyst, demonstrating many new “daughter cysts” within the confines of a “mother cyst”. Note the “rolls and scrolls” appearance of the cyst. What dangerous lesion should be considered if this was located anywhere other than the scalp, was greater than 5 cm in size, and showed mitotic activity?
A trichilemmal carcinoma
True or false: a pilar cyst is also known as a trichilemmal cyst.
True
This type of cyst is the most common cause of a congenital neck mass. They typically occur on the sides of the neck and have lymphoid follicles histologically. What type of cyst is it?
Branchial cleft cyst
This type of cyst is typically found midline, most often in the suprasternal notch. This type of cyst typically lacks lymphoid follicles, has ciliated epithelium, and may have concentric smooth muscle and cartilage. What type of cyst is it?
Bronchogenic cyst
This type of cyst occurs along the anogenital raphe and histologically is filled with debris. What type of cyst is it?
Median raphe cyst
Horn cysts and pseudo-horn cysts are often seen in seborrheic keratoses. What’s the difference between these?
Horn cysts are completely inclosed in the epidermis, while pseudo-horn cysts connect to the surface of the skin
True or false: hidroacanthoma simplex is also known an intraepidermal poroma.
*Image: hidroacanthoma simplex.
True; the terms can be used synonymously
Epidermoid cysts (epidermal inclusion cysts) with pilomatrical differentiation (e.g. with areas of shadow cell keratinization) are markers for what syndrome?
Gardner syndrome
If a “median raphe cyst” occurs on female genitalia, it is instead called:
*Image: median raphe cyst.
Cutaneous ciliated cyst
*Note: these can also occur in other locations, most often on the legs of females (actually, this is a more common location than the genitals).
Can cutaneous ciliated cysts occur in men?
Yes; although cutaneous ciliated cysts are thought to relate to Mullerian duct remnants, they are occasionally noted in men.
*Note: cutaneous cilated cysts occur most commonly on the legs of females, although they can sometimes occur on the genitals.
True or false: in a cutaneous ciliated cyst, the lining of the cyst is always ciliated.
*Image: cutaneous ciliated cyst
True; this is in contrast to a median raphe cyst, which has a variable cyst lining (it may or may not have a ciliated epithelial lining).
*Image: median raphe cyst
This type of cyst most commonly occurs at the back of the tongue or on the neck. It’s comprised of thyroid follicles. What type of cyst is it?
Thyroglossal duct cyst
What is the differential diagnosis for an abnormal spindle cell proliferation that’s slammed up against the epidermis?
*Hint: use the mnemonic “SLAM”
- Spindle cell squamous cell carcinoma (keratin positive)
- Leiomyosarcoma (smooth muscle actin positive)
- Atypical fibroxanthoma (diagnosis of exclusion)
- Melanoma (S100 positive)
True or false: acantholysis is never seen in keratoacanthoma.
True; this is one of the features that helps to distinguish keratoacanthomas from squamous cell carcinomas
*Note: keratoacanthomas regress through terminal differentiation, while SCCs never do. Keratoacanthomas essentially keratinize themselves to death
True or false: keratoacanthomas often undergo regression immediately after they’re biosied.
False; they often undergo rapid growth after they’re biopsied. This feature helps to distinguish them from SCCs
True or false: Padget’s disease of the breast represents intraepidermal extension of underlying intraductal carcinoma.
True
What’s the diagnosis here?
*Note: at scanning magnification, this lesion appears to have germinal centers, but on closer inspection there are atypical epithelial cells surrounded by lymphocytes.
Lymphoepithelioma-like carcinoma
True or false: neutrophilic microabscesses and eosinophils in the dermal infiltrate are often seen in keratoacanthomas.
True; both of these features help to distinguish keratoacanthomas from SCCs
Below is a picture of extra-mammary Padget’s disease. This can be caused by an underlying breast carcinoma, by an adnexal carcinoma, by a gut carcinoma, by a urothelial carcinoma, or by Toker cells that are found in the epidermis of skin along the milk-lines. When Toker cells proliferate to form a bening condition (i.e. not Padget’s disease, which is malignant), the condition is called:
Clear cell papulosis (extra-mammary Padget’s disease is the malignant counterpart)
What is the staining pattern for Padget’s disease with respect to keratin, CEA, and S100? Is is diastase resistant?
Padget’s disease is:
- Keratin +
- CEA+
- S100-
- Diastase resistant
Name this tumor.
Trichofolliculoma
Name this tumor.
Lymphadenoma (adamantinoid trichoblastoma)
*Note: called a “lymph”adenoma due to the precence of inflammatory cells in the center of the basaloid islands
Name this tumor (clinically it often appears as a doughnut shaped papule on the cheek of a young women).
Desmoplastic trichoepithelioma
Name this tumor.
Trichoepithelioma
Name this tumor.
Trichoblastoma
What are the two types of chondroid syringomas?
Small tubular type and branching alveolar type
Name this tumor.
Chondroid syringoma (small tubular type)
Name this tumor.
Chondroid syringoma (branching alveolar type)
Name this tumor.
Poroma
Name this tumor.
Syringofibroadenoma of Mascaro
Name this tumor.
Syringofibroadenoma of Mascaro, neoplastic type
Name this tumor (hint: these are often found on the distal extremities of young African Americans).
Papillary “eccrine” adenoma (tubular apocrine adenoma)
True or false: there is no true distinction between papillary “eccrine” adenoma and tubular apocrine adenoma.
True
*Note: these are often found on the dorsal hand or foot of a black child.
Name this carcinoma.
Adenoid cystic carcinoma
This tumor has been poetically described “blue islands in a sea of snot”.
Mucinous carcinoma
Name this tumor (hint: these often present as dusky tender nodules in children).
Eccrine angiomatous hamartoma
*Image: eccrine component on the right, and vascular component on the left.
What’s the other term for a schwannoma?
Neurilemmoma
