Dermatopathology Conference Flashcards
Structures from which spindle cells arise in the dermis
- Vessels
- Fibroblasts
- Erector pilli muscles
- Nerve sheath (neurofibroma vs schwannoma)
- Adipocytes
__ often have mast cells sprinkled in
Neurofibromas often have mast cells sprinkled in
As opposed to schwannomas
Non-melanocytic pigmented lesions
Dermatofibroma (common)
Seborrheic keratosis (common)
Other dermal spindle cell lesions (less common)
Barricade bodies
Describes the architecture of a schwannoma, with Antoni A areas of interlacing bundles of spindle cells with wavy/oval nuclei, and hypocellular Antoni B areas that stain with CD34.
Pylar cyst
Almost always occur on the scalp.
Proliferating pylar tumor
Histologically appears like numerous pylar cysts in one location.
Must also consider a SCC arising from a pylar cyst.
Like pylar cysts, almost always occur on the scalp.
Epidermoid cyst
Hypertrophic scar
Very nodular, partially hyalinized collagen
Hemosiderin-filled histiocytes in a melanoma bed
Sometimes when you apply Monsel’s solution to seal a wound, you wind up with a ton of hemosiderin-laden macrophages at the surgical site, since the solution has a lot of ferrous sulfide as a component.
This can be easily mistaken for melanoma! The hemosiderin-laden macrophages can masquerade as melanoma.
You can tell them apart by 1. lack of inflammation, 2. cell morphology, and 3. melanin vs iron stains.
Gel foam typical appearance
Aluminum-chloride-laden macrophages
Another surgical site closing material
Subtle, often missed anyway, but don’t be confused into thinking it is something dangerous
Dermatophytes invading a hair follicle
Note the spores and the hyphae invading the hair follicle
Markers associated with melanoctes
HMB-45, a marker of immature melanosomes
MART-1, a melanocyte marker of unknown function
S-100 (for neural crest origin)
Keloid histology
Layers of the skin
Corneum: The keratin.
Lucidum: Between corneum and granulosum, lysine-residue rich. Found only in palms and soles.
Granuolsum: Granulated
Spinosum: “Spinous” due to desmoglein interactions.
Basale: Basal cells.
Glomus cells
Undifferentiated smooth muscle cells which are thermoregulatory units.
Appear in glomus tumors and in glomuvenous malformations (aka glomangiomas). A glomangioma is shown.
The classical cells have round nuclei with slightly varying size. In a glomuvenous malformation, they the nuclei are whole and there is an amphophilic to eosinophilic stroma surrounding branching, capillary sized vessels. In a glomus tumor, the nuclei are “punched-out”, or papillary thyroid-like.
