Primary Cutaneous Anaplastic Large Cell Lymphoma with IRF4/DUSP22 Rearrangement

Siba El Hussein, MD
2 min readDec 2, 2022

Lessons From the Friday Unknowns

The skin biopsy shows a dense dermal infiltration with epidermotropism. The infiltrating lymphocytes ranging in size from small to medium size. The epidermis shows epidermotropism of smaller lymphocytes, few of which few are cerebriform. The neoplastic cells display irregular nuclear contours with occasional prominent nucleoli. The cytoplasm is scant to moderately abundant. Mitoses are numerous; no necrosis is noted.

The neoplastic cells are positive for CD3, CD30, CD43 and negative for ALK1 and BCL6. Cells in the dermis are strongly diffuse for CD30, while those in epidermis are faintly positive or negative; no donut-like inclusions are noted. The neoplastic cells ae negative for CD4, CD5, CD7, CD8, CD10, CD20, CD21 and cyclin D1. CD10 stains stroma cells. Proliferation rate is ~100 by Ki 67 stain. Kappa and Lambda ISH are negative.

Per outside report, FISH for IRF4/DUSP22 (6p25) rearrangement is positive.

CD3
CD20

Link to digital slides: https://bit.ly/3WEWJIa | Case 1

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Siba El Hussein, MD

Hematopathology | Cytopathology | Molecular pathology | Digital pathology | Data science | Machine learning