A wolf in sheep's clothing: enteropathy associated T-cell lymphoma involving a nasal polyp masquerading as primary mucosal CD30-positive T-cell lymphoproliferative disorder.

Abstract

CASE SUMMARY An 81-year-old woman presented with nose bleeds and a left anterior nasal septal polyp. Excision biopsy revealed a mucosal lymphoid infiltrate with features of anaplastic large cell lymphoma (ALCL) (Figure 1A). The neoplastic cells were positive for CD45, CD30, EMA (focal), CD3 (variable), CD2, CD25, pSTAT3, TIA1 (focal) and granzyme-B (focal), but negative for ALK, CD5, CD7, CD4, CD8, TCR, CD103 and B-cell markers. Ki67 proliferation approached 100%. EBV encoded small RNA was negative by in situ hybridisation. Fluorescent in situ hybridisation analysis did not detect DUSP22 or TP63 rearrangements. In view of the clinically localised disease, the proffered diagnosis was mucosal CD30+ T-cell lymphoproliferative disorder (T-LPD) akin to primary cutaneous CD30+ T-LPD, with the caveat imaging should confirm localised disease, excluding systemic ALK-negative ALCL.