Skin Biopsy Diagnosis: Infections, Granulomas & Tumors

This video with Dr. Tom Davis provides a review of 8 select dermpath cases – presenting a challenging and diverse set of skin biopsy cases to test and improve diagnostic skills. It covers a range of conditions, including infections like cutaneous leishmaniasis and coccidioidomycosis, inflammatory disorders like granuloma annulare, and neoplastic tumors. The session is an excellent resource for anyone studying dermatopathology, offering a practical way to learn from real-world examples.

To view the slides for this presentation, please follow this link: https://sagis.pathpresenter.net/#/public/presentation/display?token=df63906f

This review covers a variety of challenging biopsy cases, including:

• Cutaneous Leishmaniasis: A parasitic infection identified by “soap bubble” vacuoles in histiocytes.
• Granuloma Annulare: Characterized by nodular collections of epithelioid histiocytes.
• Syringocystadenoma Papilliferum: A benign adnexal tumor with papillary fronds.
• Giant Cell Tumor of Tendon Sheath: A deep tumor with plump fibroblasts and osteoclast-like giant cells.
• Coccidioidomycosis: A fungal infection identified by large spherules.
• Porokeratosis Ptychotropica: A rare variant of porokeratosis with scattered coronoid lamellae.
• Lichen Nitidus: Identified by the “ball and claw” phenomenon.
• Langerhans Cell Histiocytosis: A histiocytic disorder with a mixed infiltrate of Langerhans cells and eosinophils.

Chapter Breakdown:

Case 1: Cutaneous Leishmaniasis [02:18]

The video presents a case of cutaneous leishmaniasis, a parasitic infection. The speaker points out the characteristic “soap bubble” appearance of the infected histiocytes and the presence of plasma cells in the inflammatory infiltrate.

Case 2: Granuloma Annulare [06:14]

This section covers granuloma annulare. The speaker describes the nodular collections of epithelioid histiocytes and notes the patchy nature of the infiltrate, which helps distinguish it from other conditions.

Case 3: Syringocystadenoma Papilliferum [08:14]

The video presents a case of a syringocystadenoma papilliferum, a benign adnexal tumor. The speaker highlights its characteristic features, including papillary fronds and a stromal plasma cell infiltrate.

Case 4: Giant Cell Tumor of Tendon Sheath [11:33]

This chapter focuses on a deep-seated tumor, the giant cell tumor of tendon sheath. The speaker describes the circumscribed neoplasm containing plump fibroblasts and osteoclast-like giant cells.

Case 5: Coccidioidomycosis [14:55]

The video shows a case of coccidioidomycosis, a fungal infection. The key diagnostic feature highlighted is the large spherules with thick, refractive walls.

Case 6: Porokeratosis Ptychotropica [18:04]

This section covers a rare variant of porokeratosis. The speaker explains its histologic hallmarks, which include a thickened cornified layer and multiple scattered coronoid lamellae.

Case 7: Lichen Nitidus [21:00]

The video presents a case of lichen nitidus. The speaker describes the characteristic “ball and claw” phenomenon, where discrete inflammatory foci are encircled by elongated epidermal rete ridges.

Case 8: Langerhans Cell Histiocytosis [24:13]

The final case is Langerhans cell histiocytosis. The speaker notes the mixed infiltrate of lymphocytes and large epithelioid Langerhans cells, emphasizing the irregular, notched nuclei and the presence of eosinophils.