EBV+ MUCOCUTANEOUS ULCER
Lessons From the Friday Unknowns
The patient presented with an abdominal mass. An ulcerated duodenal mass was found upon endoscopy.
Histologic sections show a neoplastic lymphocytic infiltrate involving the submucosal intestinal mucosa.
The infiltrate is composed of large neoplastic cells with vesicular chromatin, prominent nucleoli, and large amount of “clear” cytoplasm (Hodgkin-like cells).
Admixed inflammatory cells are detected in the background, composed of small lymphocytes, histiocytes, plasma cells, and numerous eosinophils.
The large neoplastic cells are positive for PAX5, CD30, MUM1, CD79a (weak), OCT2, and negative for CD20, CD15, BOB1, and ALK1. CD30 also highlights some small cells. CD45 is difficult to interpret due to high background staining, but some large neoplastic cells are negative for CD45.
EBER by in situ hybridization is positive in some large cells as well in some small cells.
Links to digital slides: https://bit.ly/3vJ2rLb | Slides labeled case 2