Dermatopathology Case Study

Hisopathological findings: Dermis shows well defined nodular masses or collection of basaloid cells with crowding of nuclei. There is fencing or ‘palisade-like’ arrangement of basaloid cells at the periphery of these masses. Basaloid cells are surrounded by ‘retraction spaces’ seen as clear clefts. Presence of melanin pigment amongst basaloid cell masses is suggestive of epidermal or epithelial origin of cells. Stroma surrounding these nodular masses is fibrovascular. Infiltrate is seen in the stroma. There are no mucin deposits.
Note:- Presence of pigment does not qualify for pigmented basal cell carcinoma as melanin pigment is a common finding in BCC seen Asian people.

Diagnosis – Basal Cell Carcinoma

Hisopathological findingsThere are collections of basaloid cells forming clusters some of them appears to be connected with overlying epidermis. There are no retraction spaces around these nodules. However, central cysts containing keratin is seen which are appreciated in lower magnification. There are no crowding of nuclei of these basaloid cells. No inflammatory infiltrate is seen.

Diagnosis – Trichoepithelioma

Hisopathological findingsThe findings require careful examination under medium to high power. There is suprabasal cleft as seen in pemphigus vulgaris. Closer look shows round keratinocytes in the Stratum Malphigii almost in the full thickness of the epidermis. However, acantholytic keratinocytes are still attached to each other or holding each other. Appearance is classical but closest differential diagnosis is pemphigus vulgaris. Dermal changes are uncharacteristic.

Diagnosis – Hailey Hailey Disease

Hisopathological findingsThe findings require careful examination under low, medium and high power. At low power, there is acanthosis and papillomatosis of the epidermis. At higher magnification, suprabasal cleft in papillomatous epidermis is seen. Closer look shows eosinophilic cells with eccentric pyknotic nucleus. Such cells are predominantly seen in Stratum spinosum and granulosum. Higher up in the epidermis, round cells with plump keratohyaline granules appearing granular. Dermal changes are uncharacteristic.

Diagnosis – Darier’s Disease

Hisopathological findingsEpidermis shows flattening or blunting of rete ridges. The findings require careful examination under medium and high power. At medium power, in the papillary dermis, there are blunt ended and slightly ‘curvilinear’ and thickened collagen bundles. As against normal homogenous eosinophilic color typical of collagen tissue, collagen bundles appears yellowish brown. Melanophages are also seen. Infiltrate is minimal.

Diagnosis – Ochronosis

Hisopathological findingsBroad band like upper dermal infiltrate is present obscuring the dermo-epidermal junction and infiltrating the epidermis covered with parakeratotic scale crust. The infiltrate is composed of uniform large cells having abundant pale eosinophilic cytoplasm with central to eccentric reniform vesicular nuclei, with, few admixed eosinophilis.

Diagnosis – Langerhan’s Cell Histiocytosis

Hisopathological findingsAcanthotic epidermis shows full thickness permeation by single and small nests of large round cells having abundant pale eosinophilic to clear cytoplasm with large vesicular nucleus having 1-2 nucleoli. Rare duct like structure can be recognized on careful search.

Diagnosis – Mammary Paget’s Disease

Hisopathological findingsBroad, asymmetric, uncircumscribed, junctional melanocytic lesion composed of confluent proliferation of atypical melanocytes. There is prominent pagetoid spread with epidermal effacement/consumption. Melanocytes show cytological atypia in the form of vesicular pleomorphic nuclei with nucleoli. Fibrosis, patchy band like lymphocytic infiltrate and numerous melanophages are seen in papillary dermis.

Diagnosis – Malignant Melanoma in Situ

Hisopathological findingsIntraepidermal tumor is seen in the form of discrete nests and few single cells at various levels in acanthotic epidermis. The tumor is infiltrating upto upper reticular dermis in the form of variable sized lobules and nests. Surrounding stroma shows horizonatally parallel fibrosis and perivascular lymphocytic infiltrate with few eoisnophils. The individual tumor cells are small cuboidal to large squamoid cells with dyskeratosis and few cells showing clear cell change. Nuclei are large, highly pleomorphic, vesicular with prominent nucleoli and numerous atypical mitotic figures. An occasional duct like structure can be noted on careful search.

Diagnosis – Porocarcinoma

Hisopathological findingsThickened parakeratotic stratum corneum covers the epidermis showing psoriasiform hyperplasia. Solitary lymphocytes with perinuclear halo and having slightly larger and hyperchromatic nuclei are seen extensively infiltrating the epidermis in the absence of associated spongiosis, more prominently involving lower one third and tagging the basal layer. Few epidermotropic lymphocytes have indented/irregular nuclear contour. An occasional tiny intraepidermal collection of atypical lymphocytes consistent with Pautrier’s microabscess is to be noted. Papillary dermis shows moderately dense band like lymphocytic infiltrate with perivascular accentuation and coarse collagen bundles.

Diagnosis – Mycosis Fungoides

Hisopathological findingsThere is a large intraepidermal vesicle present centrally, with the cavity bearing numerous neutrophils and RBC. The base of blister is composed of necrotic basal keratinocytes. Within the upper-mid dermis, there is a moderately dense perivascular and interstitial inflammatory infiltrate composed predominantly of neutrophils. The dermal capillaries appear ‘sick’ with fibrinoid vessel wall necrosis and intramural fibrin. Numerous neutrophils are seen within the vessel walls, associated with extravasation of RBC into the interstitium and mild karyorrhexis.

Diagnosis – Leukocytoclastic Vasculitis (Bullous)

Hisopathological findingsThe epidermis displays atrophy, parakeratosis and mild spongiosis. There is a band of papillary dermal sclerosis underpinned by a dense lymphocytic infiltrate in the upper/ mid dermis. Focal vacuolar interface change is noted. A few dilated capillary loops are seen in the papillary dermis.

Diagnosis – Lichen Sclerosus

Hisopathological findingsThe collagen in the deep dermis and interlobular septae (fat) demonstrates early sclerosis, associated with a perivascular lymphohistiocytic infiltrate. There is a septal panniculitis with the inflammatory infiltrate spilling over into the lobules. The septae appear thickened. Focally in the deeper fat lobules there is a large area of dystrophic calcification surrounded by a histiocytic infiltrate.

Diagnosis – Morphoea with Dystrophic Calcification

Hisopathological findingsMild epidermal atrophy, associated with a band like lichenoid infiltrate and numerous melanophages. No basement membrane thickening, deeper infiltrate/ mucin to suggest DLE. But do note that FDE, DLE and LPP share similar histological features and can be impossible to distinguish on histological grounds alone. CPC +- DIF essential.

Diagnosis – Lichen Planus Pigmentosus

Hisopathological findingsThe epidermis appears relatively normal. The dermis appears ‘busy’ with a moderately dense perivascular and interstitial lymphohistiocytic infiltrate. Lymphocytes and histiocytes are seen infiltrating between the collagen bundles, which appear separated apart. Focal swelling and degeneration of collagen fibers is seen. A few plasma cells are seen in the interstitium, associated with a tinge of bluish strands (suggestive of interstitial mucin).

Diagnosis – Interstitial Granuloma Annulare

Histopathologic findingsMild acanthotic epidermis. Separation at dermo-epidermal junction. Dense neutrophilic infiltrate in the dermis. Enlarged separated keratinocytes with ground-glass appearance and multi-nucleation.

Diagnosis – Persistent Orolabilal Herpes

Histopathologic findingsFull thickness dysplasia with nuclear disarray giving rise to wind- blown appearance. There are several mitotic figures and apoptotic keratinocytes. Basement membrane is intact. Few mature lymphocytes can be observed in the epidermis. However, there is dense lymphocytic infiltrate in the superficial dermis.

Diagnosis – Bowen’s Disease

Histopathologic findingsFlattened rete pegs. Occasional follicular plugs. Mild peri-vascular lymphoytic infiltrate in superficial dermis. RBC Extravasation. Apoptotic keratinocytes.

Diagnosis – Graft-Versus-Host Disease

Histopathologic findingsAcanthotic epidermis with large keratinocytes predominantly in the granular layer of epidermis whereas lower layers of the epidermis is relatively spared. These enlarged keratinocytes have vesicular nuclei and basophilic cytoplasm. Prominent nucleoli can be observed.

Diagnosis – Epidermodysplasia Verruicformis

Histopathologic findingsAcanthotic epidermis with spongiosis. Dermal edema with plasma accumulation in places. Dense eosinophilic infiltrate throughout whole thickness of dermis extending upto the subcutaneous fat leading to nodular collection of eosinophils. Several eosinophilic flame figures can also be observed. Leukocyte of non-eosinophilic lineage is virtually absent.

Diagnosis – Eosinophilic Cellulitis

Histopathologic findingsThere is a plug in the dilated hair follicle. Many foamy histocytes are present and surround the hair follicle. A small apocrine duct is noted and inserted into the follicular epithelium.

Diagnosis – Xanthomatous Fox-Fordyce Disease

Histopathologic findingsThe epidermis and dermis are relatively normal. There is a lobular panniculitis. Lipophagic fat necrosis and multinucleated giant cells are present in the fat lobules. Radially arranged needle-shaped crystal or clefts are seen in some adipocytes and/or surround by histiocytes.

Diagnosis – Subcutaneous Fat Necrosis of Newborn

Hisopathological findingsThe epidermis is partially eroded. There is a diffuse calcification in the dermis and subcutis with eccrinhe glands and adipocytes necrosis. The blood vessels are ectatic in the upper dermis but the perivascular inflammation is mild. Some blood vessels have calcium deposition in their walls.

Diagnosis – Calciphylaxis

Hisopathological findingsThere a marked irregularly downward proliferation of the epithelium into the deep dermis. Some scattered dyskeratotic keratinocytes are noted is the epithelial islands. The stroma is densely fibrotic and has mixed cell diffusely infiltration, including neutrophils, lymphocytes, histiocytes, plasma cells, and multinucleated giant cells.

Diagnosis – Squamous Cell Carcinoma-Like Pyoderma Gangrenosum

Hisopathological findingsThere is a diffuse deposition of amourphous eosinophilc materials in the whole reticular dermis. Lympho-plasma cells perivascular infiltration is present. The blood vessels, eccrine glands, and some adipocytes are thickened due to the pinkish deposited materials.

Diagnosis – Nodular Amyloidosis

Histopathologic findings There is a non-ulcerated, banal lobular intradermal proliferation of capillary vessels, each lined by a monolayer of plum endothelium. Occasional larger “feeder” vessels are observed near the base. Five additional skin lesions removed simultaneously showed similar histological features.

Diagnosis – Pyogenic granuloma (multiple eruptive pyogenic granulomas)

Histopathologic findingsThis excisional punch biopsy shows an intradermal capillary vascular proliferation with conspicuous peripheral epidermal collarette formation. On closer inspection, however, there are intervening granular, amphophilic extracellular colonies of bacterial organisms.

Diagnosis – Bacillary angiomatosis (bearing a close resemblance to a pyogenic granuloma

Histopathologic findingsThere is a small, slightly elevated superficial intradermal spindle cell vasoproliferative lesion. The entire lesion is enveloped by a peripheral epidermal collarette. A conspicuous background plasma cell-rich mononuclear inflammatory cell infiltrate is present.

Diagnosis – Kaposi sarcoma (pyogenic granuloma-like variant)

Histopathologic findingsThe dermis in this punch biopsy is punctuated by multiple small clusters of delicate capillary vessels, many of which exhibit a distinctly glomeruloid architecture. The vessels are lined by plump endothelium. A striking feature is the presence of numerous eosinophilic globules. What is the underlying condition which should be excluded in this patient?

Diagnosis – Glomeruloid Haemangioma

Histopathologic findingsThis bisected punch biopsy shows a dermis and superficial subcutis punctuated by a vascular proliferation comprising multiple small clusters of capillary vessels, with a resultant “cannonball”-like low-power appearance. Some of these foci are flanked by displaced crescentic lymphatic channels. Which associated syndrome might this patient have?

Diagnosis – Tufted Angioma

Histopathologic findingsThe mid- to upper dermis is occupied by a wedge-shaped vascular proliferation, whose base is orientated towards the epidermis. The more superficial vascular spaces are congested, and are lined by a monolayer of plump, hobnail-like endothelial cells. The deeper dermal component is more subtle, with dissection of the dermal collagen by narrower vascular channels. On closer inspection, intervening deposits of haemosiderin pigment are seen.

Diagnosis – Hobnail Haemangioma (targetoid haemosiderotic haemangioma)

Histopathologic findingsThe dermis shows a vascular proliferation composed of elongated and arborizing vascular spaces, with dissection of intervening collagen bundles. In areas, the low-power appearances are distinctly reminiscent of the rete testis. Projecting into the lumens of the vascular channels are plump, hobnail-type endothelial cell nuclei.

Diagnosis – Retiform Haemangioendothelioma