Dermatopathology #1 Flashcards
This biopsy came from a plaque lesion of psoriasis. What’s the name of this sign, where alternating layers of neutrophils and parakeratosis are found in the stratum corneum?
Sandwich sign
Name four types of blue nevi.
- Common blue nevus
- Cellular blue nevus
- Deep penetrating blue nevus
- Epitheliod blue nevus
True or false: the presence of parakeratosis or eosinophils excludes the diagnosis of lichen planus.
True
What form of lupus has the highest risk of transformation to SCC?
Hypertrophic LE
True or false: sawtoothing is typically seen with a lichenoid vacuolar interface dermatitis.
False; sawtoothing never occurs along with a lichenoid vacuolar interface dermatitis
Name a pan-T marker that will be negative in the lymphocytes of mycosis fungoides?
CD7; this should be positive in all normal T-lymphocytes
True or false: dermatomyositis and lupus can be indistinguishable histologically.
True; although dermatomyositis can have an atrophic form, and lupus does not have this form (note that dermatomyositis can also show acanthosis histologically, especially from a Gottron’s papule)
In Spitz nevi, MIB-1 (Ki-67) will be negative in the deep dermal component. What does MIB-1 (Ki-67) positivity mean?
Surrogate marker for mitosis
*Image: Spitz nevus staining negative for MIB-1 (Ki-67) in the deep dermis.
True or false: pustular psoriasis may never demonstrate acanthosis.
True
*Note: early guttate lesions also don’t demonstrate acanthosis
True or false: Reiter’s disease and geographic tongue look like psoriasis histologically.
True
True or false: Spitz nevi are typically composed of both spindled and epithelioid cells.
True; older Spitz nevi composed only of epitheliod cells are suspicious for malignant melanoma.
What are the nailfold changes seen in dermatomyositis? What about lupus?
- Dermatomyositis: dilatation and dropout (“d”s for dermatomyositis)
- Lupus: glomeruloid loops (remember this because lupus can affect the kidney!)
*Image: dilatation and dropout seen in dermatomyositis
Name this lesion.
Solar lentigo
Name this lesion.
Melanotic macule
Name this lesion.
Balloon cell nevus
What type of nevus will demonstrate nevic corpuscles (looks like Meissner’s corpuscles)?
Neurotized nevus
What type of nevus often demonstrates a patchy interstitial arrangement of melanocytes?
Congenital nevus
What type of nevus is this? Note the patchy melanocytes, that, at scanning magnification, look like lymphocytes.
Congenital nevus
Name this lesion. Note clefting adjacent to the nests.
Spitz nevus
Name this lesion.
Spitz nevus
Name this nevus.
Spitz nevus
Kamino bodies represent trapped basement membrane zone in the epidermis. In what lesions are Kamino bodies found?
Spitz nevi
Name the following lesion (note both epithelioid and spindled melanocytes in the dermis).
Dermal Spitz nevus
What lesion is characterized by cells with two-toned cytoplasm?
Spitz nevus
Name this atypical melanocytic lesion.
Recurrent nevus
Name this facial lesion (note the dendritic melanocytes and the East-West orientation of these melanocytes).
Nevus of Ota
Name this atypical melanocytic lesion.
Lentigo maligna
Name this melanocytic lesion (note: this lesion falls into the “SLAM” differential).
Spindle cell melanoma
*Spindle cells “slam”ed against the dermis:
- Spindle cell SCC
- Leiomyosarcoma
- AFX
- Melanoma (spindle cell)
This melanocytic lesion is characterized by spindle cells and lymphoid aggregates. The spindle cells often have a bland appearance.
Desmoplastic melanoma
This type of melanoma is a primary soft tissue melanoma.
Clear cell sarcoma (also called melanoma of the soft parts)
This type of melanoma has a poor prognosis and is thought to relate to genomic instability of the tumor cells (note the effaced rete pattern).
Regressing melanoma (likely occurs secondary to genomic instability of the tumor cells, as opposed to the inflammatory response)
In this type of melanoma, there is no involvement at the dermoepidermal junction.
Metastatic melanoma
Name this lesion taken from a violaceous flat-topped rash.
Lichen planus
What two entities are at the top of the differential diagnosis for a lichenoid dermatitis that extends down the hair follicle? How would you distinguish these?
Lichen planopilaris and discoid lupus
Discoid lupus affects the lower hair follicle, around the isthmus, and also the ecrine coils, while lichen planopilaris tends to involve the upper hair follicle, in the indundibular area. Direct immunofluorescence is also very helpful in distinguishing these intities.
Hypertrophic LE shows a lichenoid dermatitis that is difficult to distinguish from lichen planus. What will the DIF show if this is hypertrophic LE?
“Full house” granular deposition of IgG, IgA, IgM, and C3 along the basement membrane
What condition should be considered here (note the lichenoid infiltrate and the rare melanocytic nests)?
Lichenoid regression of melanoma
What’s the diagnosis?
Porokeratosis (note the cornoid lemellae)
What three conditions can show vacuolar interface dermatitis with a “lymph in every hole”?
Mycosis fungoides, early benign lichenoid keratosis, and pityriasis lichenoides
What’s the diagnosis?
Mycosis fungoides; note the large hyperchromatic lymphocytes in the epidermis (epidermotropism), the Pautrier microabscesses, and the papillary dermal fibrosis
These atypical lymphocytes, with notched, angular, or cerebriform nuclei are best appreciated on very thin sections (1 micron). What condition is this?
Mycosis fungoides
What’s the diagnosis?
Pityriasis lichenoides
What’s the diagnosis?
Pityriasis lichenoides
What’s the diagnosis?
Pityriasis lichenoides (note the transepidermal elimination of RBCs)
What’s the most likely diagnosis?
Discoid lupus affecting the hair follicle (note the lymphoid infiltrate around the hair follicle and the keratotic spine overlying the epidermis, representing follicular plugging)
Lymphocytic infiltration of the eccrine coil can be seen in lupus, and in what other unrelated condition?
Lichen striatus
What’s the diagnosis (note “long slender sexy” rete)?
Syphilis; the “long slender sexy” rete are sometimes called “icepick” rete
What’s the diagnosis? Hint: this condition usually occurs on acral skin, although this particular biopsy is not from acral skin.
Erythema multiforme
What’s the diagnosis?
Severe erythema multiforme or TEN
What’s the diagnosis in this biopsy that looks like EM? Hint: note the acute stratum corneum, but the “paradoxical” chronic changes in the dermis, including papillary fibrosis and pigment incontinence. Note also that the infiltrate is mixed, including neutrophils and eosinophils (EM will have a purely lymphoid infiltrate).
Fixed drug eruption
What’s the eponymous name for this collection of neutrophils in the stratum corneum? Hint: this finding is often seen in psoriasis.
Munro’s microabscess
Name this condition (which isn’t always pustular). Note the psoriasiform acanthosis.
Pustular psoriasis
What’s the differential diagnosis for subcorneal pustules? Hint: use the acronymn CAT SIPS.
“CAT SIPS”
Candida, acropustulosis of infancy, transient neonatal pustular melanosis, Sneddon-Wilkinson (and IgA pemphigus), impetigo, pustular psoriasis, and Staphylococcal scalded skin syndrome
The bare underbelly sign refers to a superficial perivascular lymphoid infiltrate that prodominates above the vessel, with few lymphocytes below the vessel. It’s been likened to a vaccuum cleaner sucking the lymphocytes towards the surface. In what condition is this sign seen?
Mycosis fungoides
True or false: plasma cells are present in biopsy specimens of syphilis in 2/3 of cases.
True
This condition is basically “pustular psoriasis of the tongue”.
Geographic tongue
What’s the diagnosis?
Psoriasis
What’s the diagnosis?
Plaque psoriasis
What’s the diagnosis? Note that the granular layer is absent.
Pustular psoriasis
What’s the diagnosis? Note there is no psoriasiform acanthosis.
Guttate psoriasis; note the neutrophils above the parakeratosis and the abscence of psoriasiform acanthosis
What’s the diagnosis? Note the parakeratosis that alternates with orthokeratosis in both a horizontal and vertical pattern.
Pityriasis rubra pilaris
What’s the diagnosis? Note the scale crust that shoulders the follicles.
Seborrheic dermatitis
What’s the diagnosis? Note the parakeratosis alternating both vertically and horizontally with orthokeratosis.
Pityriasis rubra pilaris
What’s the diagnosis? Note the spongiosis and RBC extravasation in this condition that is not a pigmented purpuric dermatosis.
Pityriasis rosea
*Note: this is characterized by spongiosis and RBC extravasation. However, these features may also be seen in the spongiotic versions of pigmentary purpuras.
**Note: pityriasis lichenoides is characterized by interface dermatitis and RBC extravasation, which typically leads to hemosiderin deposition.
What’s the diagnosis? Note the spongiosis and RBC extravasation. Hint: this is not a spongiotic pigmented purpuric dermatosis.
Pityriasis rosea
*Note: it’s usually the Herald patch that’s biopsied, before the diagnosis is clinically evident.
What’s the diagnosis? Note the alternating left-to-right pattern of para- and orthokeratosis.
Inflammatory linear verrucous epidermal nevus (ILVEN)
What’s the diganosis? Note the left-to-right alternating para- and orthokeratosis.
Inflammatory linear verrucous epidermal nevus (ILVEN)
What’s the diagnosis? Note the lymphocytes sitting on top of vacuoles like “lumps of coal on pillows”.
Psoriasiform type of mycosis fungoides (the other form has a lichenoid dermatitis)
In this condition atypical lymphocytes ascend upwards within the epidermis, but are most concentrated at the dermoepidermal junction.
Mycosis fungoides
What’s the diagnosis? Note the interface dermatitis with lymphocytes sitting on vacuoles like “lumps of coal on pillows”.
Mycosis fungoides; this particular example has both an interface dermatitis and a psoriasiform acanthosis
In this condition there are long slender “sexy” rete ridges, blood vessels with no lumen (due to endothelial swelling), and in 2/3 of cases plasma cells are present.
Syphilis
What disease is known as “lues”?
Syphilis
What’s the diagnosis? Note that at scan magnification, long slender “sexy” rete ridges would also be visible.
Syphilis, also known as “lues”
True or false: pellagra, glucogonauma, and acrodermatitis enteropathica all look the same histologically.
True; note the pallor, swelling, and necrosis of the epidermal keratinocytes in combination with a normal stratum corneum
What’s the diagnosis?
A nutritional deficiency, including pellagra, glucagonauma, and acrodermatitis enteropathica
What’s the diagnosis? Note the thick granular layer as well as keratohyaline granules within the stratum corneum.
Granular parakeratosis (also known as intertriginous granular parakeratosis or axillary granular parakeratosis)
Usually if orthokeratosis is present, the underlying stratum granulosum is normal. If parakeratosis is present, the stratum granulosum layer is reduced. What are the two exceptions to this rule?
1) Granular parakeratosis: thick granular layer and parakeratosis
2) Ichthyosis vulgaris: loss of granular layer and orthokeratosis
What’s the diagnosis?
Porokeratosis
*Note: a lichenoid infiltrate is often present.
Name this reaction pattern.
Acute spongiotic dermatitis
*Note: there’a an acute stratum corneum, since the process is acute (i.e. no chance for the changes to affect the stratum corneum yet)
Name this reaction pattern. Note the spongiosis and acanthosis, but no papillary dermal fibrosis.
Subacute spongiotic dermatitis
*Note: in chronic spongiotic dermatitis there will typically be papillary dermal fibrosis and compact hyperkeratosis.
What two reaction patterns are Langerhans cell granulomas seen in? Note the Langerhans cells have ample cytoplasm, and eccentrically placed reniform (kidney-shaped) nuclei.
Acute spongiotic dermatitis and subacute spongiotic dermatitis
What is this reaction pattern? Note the compact stratum corneum and papillary dermal fibrosis.
Chronic dermatitis or lichen simplex chronicus
*Note: angiofibroplasia refers to an increased number of blood vessles and fibrosis of these
True or false: a vertical streaking pattern of collagen is characteristic of lichen simplex chronicus.
True
What’s the diagnosis? Note the cannonball-like dermatitis, subacute spongiotic dermatitis, and hemosidering deposition.
Stasis dermatitis
Name the condition represented by this penile biopsy. Note the spongiosis, flattened diamond-shaped keratinocytes, and dermal plasma cells.
Zoon’s balanitis
List four autoimmune blistering disorders that target desmoglein 1.
- Pemphigus foliaceous
- Fogo salvagem
- Pemphigus erythematosus
- Drug-induced pemphigus
*Note: pemphigus vulgaris always involves antibodies to desmoglein 3, but sometimes also involves antibodies to desmoglein 1.
List three autoimmune blistering disorders that target desmoglein 3.
- Pemphigus vulgaris (this can also involve antibodies to desmoglein 1)
- Pemphigus vegetans
- Drug-induced pemphigus (this can also be caused by antibodies to desmoglein 1)
Where does the split occur in the skin when the autoantibody in the blistering disorder targets desmoglein 1?
Within the granular layer
Where does the histologic split occur when the antibody in the autoimmune blistering disorder is directed against desmoglein 3?
Suprabasilar layer
The DIF in pemphigus vulgaris tends to be “bottom heavy”, while in this condition, the DIF is “top heavy”.
Pemphigus foliaceous
In pemphigus foliaceous, the DIF is mostly in the granular layer, while in this condition, the DIF is mostly in the basal layer.
Pemphigus vulgaris
What is it called when a patient with pemphigus vulgaris sheds their esophageal lining?
Esophagitis dessicans superficialis
This condition demonstrates “tombstonning” of the basal keratinocyte layer.
Pemphigus vulgaris
Name this condition. Note the suprabasilar acantholysis with a tombstone row of remaining keratinocytes. Also, note the pseudopapillae, which represent dermal papillae.
Pemphigus vulgaris
Name this type of pemhigus vulgaris that shows eosinophilic collections and pseudoepitheliomatous hyperplasia. Note that neutrophils can also be present, but the form where eosinophils are present is more common.
Pemphigus vegetans
What’s the diagnosis? Note: both clinically and histologically there’s an overlap in this condition between erythema multiforme and pemphigus vulgaris.
Paraneoplastic pemphigus
What’s the diagnosis?
Hailey-Hailey
What’s the diagnosis?
Hailey-Hailey
What’s the diagnosis?
Hailey-Hailey
What are the two most likely possible diagnoses?
Darier’s disease or Grover’s disease
What are the two most likely diagnoses? Note the acantholysis and dyskeratosis.
Darier’s disease or Grover’s disease
What are the two most likely diagnoses?
Darier’s disease or Grover’s disease
What’s the diagnosis?
Grover’s disease
What’s the diagnosis?
Porphyria cutanea tarda; note the caterpillar bodies and dermal festooning
In what condition is “festooning” seen? What causes it?
Porphyria cutanea tarda; caused by hyalinization of the dermal blood vessels
What’s the diagnosis? Note the cell death out of proportion to the number of lymphocytes.
Erythema multiforme, SJS, or TEN
What’s the most likely diagnosis? Use the “PLAID” mnemonic for neutrophils in the dermal papillae.
Dermatitis herpetiformis
PLAID:
Pemphigoid (bullous)
Lupus (bullous)
EBA (“acquisita” for “A”)
Linear Immunoglobin A (“Immunoglobin” for “I”)
Dermatitis herpetiformis
What’s the most likely diagnosis?
Dermatitis herpetiformis
What’s the diagnosis? Note: if DIF was performed, IgA would be seen in a linear fashion.
Linear IgA bullous dermatosis
Note: neutrophils are found in the subepidermal vesiculation, just like in DH
Use the mnemonic “PLAID” to come up with a differential diagnosis for this subepidermal blister with inflammatory cells.
“PLAID”
- Pemphigoid (bullous)
- Lupus (bullous)
- EBA (“Acquisita” for “A”)
- Linear IgA (“I” in “IgA” for “I”)
- DH
What’s the most likely diagnosis? Note the subepidermal blister filled with eosinophils.
Bullous pemphigoid or EBA (eosinophils can be seen with either; further testing is needed to distinguish the two)
With DIF, an “n” (lower case “n”) serrated pattern is seen. What is the more likely diagnosis: bullous pemphigoid or EBA?
Bullous pemphigoid has an “n” serrated pattern; with EBA a “u” serrated pattern is usually seen
List three ways that the histologic diagnosis of BP vs EBA can be determined.
- DIF with salt-split skin
- IIF with salt-split skin
- Immunoblotting
What’s a Schaumann body?
Cytoplasmic laminated calcifications seen in granulomatous diseases, such as sarcoidosis
What is the diagnosis? Note the patchy interstitial histiocytes, lymphocytes, and mucin, which give the appearance of a “busy dermis” at low power.
Interstitial granuloma annulare (the other two histologic forms are palisading GA and subcutaneous GA, the later of which can be difficult to distinguish from a rheumatoid nodule)
True or false: mucin is often present in granuloma annulare.
True; on H&E if the mucin is not clearly visible, you might notice fenestrations between the collagen fibers where mucin is present. You may want to stain for mucin.
What’s the diagnosis? Note the histiocytes which are surrounding altered collagen and mucin.
Palisaded granuloma annulare (this is less common than the interstitial variety)
*Note the histiocytes which are surrounding altered collagen and mucin.
What condition might you consider if you see granuloma annulare-like features but without mucin, and with elastolysis?
Actinic granuloma (annular elastolytic giant cell granuloma)
*Note: some people think actinic granuloma is “granuloma annulare on sundamaged skin”
What condition might you think of if there’s granulomatous changes, alternating with dead collagen, in lasagna-like layers?
Necrobiosis lipoidica
*Note: there will be top-to-bottom and side-to-side involvment of the biopsy
True or false: plama cells and multinucleated giant cells are common in necrobiosis lipoidica.
True
What is the diagnosis? Note there’s a pallisading granuloma surrounding deeply staining eosinophilic fibrin.
Rheumatoid nodule or subcutaneous (deep) granuloma annulare; these two entities are histologically indistinguishable
What’s the diagnosis in this biopsy from the face that is very TB-like?
Lupus miliaris disseminata faciei (acne agminata); this is a form of caseating granulomatous rosacea
*Note: it’s named based on it’s histologic similarity to miliary TB
What’s the most likely diagnosis? What’s in the differential diagnosis?
Sarcoidosis; the differential diagnosis includes Crohn’s disease, Melkersson-Rosenthal syndrome, tuberculoid leprosy, silica granuloma (polarizable material), and granulomatous rosacea
*Note the “naked granulomas”
True or false: the diagnosis here could be sarcoidosis.
True; there are often epithelioid histiocytes and multinucleated giant cells
What’s the diagnosis? The appearance of these lesions has been resembled to “pepper bacon”.
Necrobiotic xanthogranuloma
What’s the most likely diagnosis in this image of “bad bacon” (if necrobiosis lipoidica looks like “strips of bacon”, then this condition is “bad bacon” with cholesterol clefts and karyorrhexis debris).
Necrobiotic xanthogranuloma
What’s the most likely diagnosis from this yellow-orange papule on a child’s face?
Juvenile xanthogranuloma
What’s the most likely diagnosis? Note the histiocytes with two-toned cytoplasm, sitting in little white lacunae.
Reticulohistiocytic granuloma (or could also be a biopsy from multicentric reticulohistiocytosis)
What’s the diagnosis in this patient with arthritis and “coral beading” around the nailfold? Note the two-toned cytoplasm.
Multicentric reticulohistiocytosis (if there was only a single lesion, the diagnosis would be reticulohistiocytic granuloma)
In what granulomatous disease is emperipolesis seen? Note that the lymphocytes just “walk right through” the cytoplasm of the histiocytes. The lymphocytes are not contained within phagolysosomes and they’re not degenerating.
Rosai-Dorfman disease
What type of cell is identified?
Langerhans cells
What’s the diagnosis? Note the polymorphous infiltrate with prominent edema. Many of the cells have reniform (kidney-shaped) nuclei.
Langerhans cell histiocytosis
*Note: Langerhans cells will be S100 positive.
What’s the most likely diagnosis in this biopsy from a yellowish papule? Note the lipid deposition seen on scanning magnification.
Xanthoma
What’s the diagnosis? Note that histiocytes are present, as well as foamy histiocytes, and also extra-cellular lipid that hasn’t yet been phagocytosed.
Eruptive xanthoma; the lipid has been deposited so rapidly that the histiocytes haven’t had time to engulf the lipid
What are the big purple cells in the image? Hint: these are often found in xanthomas.
Foamy histiocytes
What’s the diagnosis on this eyelid biopsy? Note the sheets of foam cells within the dermis.
Xanthelasma Palpebrarum
What’s the diagnosis in this fibrotic nodule that contains foam cells?
Tuberous xanthoma
What’s the diagnosis in this clinically verrucous papule with foam cells within the dermal papillae?
Verruciform xanthoma
True or false: the following biopsy could represent LCV, given the fibrin deposition.
True; fibrin deposition within the vessels is typical, along with perivascular infiltrate with neutrophils
True or false: this biopsy could represent temporal arteritis.
True; note the giant cells (hence the name “giant cell arteritis”) and disruption of the muscular “wreath” typically of arteries (veins usually have “bundled” musculature)
This vasculitis typically affects the small-medium sized arteries and arterioles in the deeper dermis.
Polyarteritis nodosa
What’s the diagnosis in this biopsy from the scalp of an elderly male? Note the tubules of glycogenated cells and prominent vascular component with extravasated RBCs and hemosiderin.
Metastatic renal cell carcinoma
Confirmation with CD10 (positive) and PAS (positive)
What’s the diagnosis from this clinically pigmented lesion? Note the central superficial dilated blood vessels with hobnail nuclei and peripheral proliferation of small vessels.
Targetoid hemosiderotic hemangioma
*Note: likely results from trauma to a pre-existing hemangioma
The deposition of which substance cuases the condition below?
Homogentisic acid
What granulomatous vasculitis is this most likely to be?
Churg-Strauss granulomatosis (eosinophils are common in the tissues as well as in the peripheral blood)
What’s the most likely diganosis? Note the huge granuloma that looks like a flame figure (seen in Well’s syndrome).
Churg-Strauss granuloma
What’s this structure called? Note the granules from eosinophils that are adhering to collagen bundles.
Flame figure (seen in Well’s syndrome)
True or false: this biopsy likely represents Wegener’s granulomatosis.
True
What’s the most likely diagnosis in this granulomatous vasculitis?
Wegener’s granulomatosis
What’s the most likely diagnosis from this facial biopsy showing chronic LCV?
Granuoma faciale
*Note: there are many eosinophils.
**Note: the lesion occurs on the face, but there are NO granulomas seen histologically, despite the name
What two chronic LCV conditons could this biopsy represent?
Granuloma faciale or erythema elevatum diutinum
True or false: extracellular cholesterol deposits might be seen in this condtion.
True; this is erythema elevatum diutinum, which, in chronic lesions, can have extracellular cholesterol deposits. This is due to years of RBC extravasation in this chronic condition.
What could the diagnosis be in this patient with HIV? Note the very “woody” appearance of this biopsy.
Erythema elevatum diutinum
What could the diagnosis be in this patient with HIV? Note the inflammatory debris where a vessel used to be.
Erythema elevatum diutinum
What’s incidental vasculitis?
Vasculitis seen at the base of an ulcer or next to suppurative folliculitis that may not represent a true vasculitis process
*Note: incidental vasculitis at the base of an ulcer
What’s the most likely diagnosis in this biopsy with papillary dermal edema and a dense neutrophilic infiltrate?
Sweet’s syndrome
What’s the most likely diagnosis? Hint: this lesion is transient.
Acute urticaria (the neutrophils have not yet had time to undergo diapedesis through the vessel walls)
What’s the most likely diagnosis? Note the neutrophils that have undergone diapedesis through the vessel wall. Hint: this is a transient lesion.
Chronic stage of an urticarial wheal
What’s the diagnosis? Note the flame figures that resemble the centers of Churg-Strauss granulomas, except that there’s no histiocytic palisade.
Well’s syndrome (eosinophilic cellulitis)
What’s the diagnosis?
Pigmented purpuric eruption
What group of disorders is characterized histologically by the coat-sleeve anomaly (lymphoid capillaritis)?
Gyrate erythemas
What’s the diagnosis? Note the perivascular lymphoid inflammation.
Tumid lupus
*Note: there will usually be dermal mucin and lymphocytes around the eccrine coil
What’s the diagnosis?
Tumid lupus
True or false: this biopsy is consistent with a diagnosis of Sweet’s syndrome.
False; the papillary dermal edema is reminiscent of Sweet’s syndrome, but the lymphoid infiltrate (as opposed to neutrophilic) is much more characteristic of polymorphous light eruption
This condition is a distinct clinical picture that may be a manifestation of lupus erythematosus.
Degos disease
*Note: patients may develop bowel perforation and stroke.
This disease presents as red papules that develop ivory white atrophic centers. Patients may develop bowel perforations and strokes.
Degos disease
In this condition there’s eosinophils and a dense wedge-shaped perivascular lymphoid infiltrate. Focal LCV may be present.
Insect bite
True or false: this could be consistent with an insect bite.
True
This condition presents on acral skin and is characterized by “fluffy edema” and expansion of vessel walls.
Perniosis
This condition is characterized by “fluffy edema”.
Perniosis
What’s the diagnosis?
Cryoglobulinemia
What’s the diagnosis?
Cholesterol emboli
What’s the diagnosis?
Stasis change
What’s the diagnosis?
Stasis change
This condition is characterized by perifollicular purpura.
Scurvy
*Note the corkscrew hair (the hair can be seen twice in the follicle)
