Abstract

CD30, also known as TNFRSF8, is a member of the TNF superfamily that positively regulates apoptosis through NFkB and MAPK pathways. CD30 expression can be observed within reactive cutaneous infiltrates (e.g. scabies/bite reaction) or lymphoproliferative disease (e.g. Lyp, MF, ALCL). Intravascular cells that express CD30 in the skin are infrequently encountered and can raise alarm for aggressive lymphoma. CD30 expression in keratoacanthoma (KA) has been previously studied, with evidence of scattered CD30+ activated T-cells possibly triggering or modulating apoptosis and tumor involution/regression. A 87-year-old man with history of heart transplant presented with an acutely tender, >2cm crusted plaque on the right forearm of several weeks duration. Microscopically, expansive infundibulocystic hyperplasia with glassy keratinocytes formed an exoendophytic silhouette. Mixed cell inflammation, especially suppuration was noted in the dermis: stains were negative for organisms. Focal intravascular atypical cells were also identified in a superficial vessel, with medium-sized cells exhibiting pleomorphic nuclei and finely dispersed chromatin: strong labeling with CD30 was noted, without similar cells elsewhere in the segment. The patient underwent surgical removal for giant keratoacanthoma. Atypical intravascular CD30+ cells can be disconcerting associated with aggressive intravascular lymphoma. The literature has many reports of so-called “benign atypical intravascular CD30+ cells” outside the spectrum of lymphoproliferative disease, most recently associated with traumatic pyogenic granuloma and lichen sclerosus. It is imperative to consider lymphoma when detected, but as our case conveys, these benign “atypical” cells seem to be a spurious event, delivering more anxiety for the pathologist than actual risk to the patient.

Financial Disclosure:
No current or relevant financial relationships exist.