Cutaneous CD30+ pseudolymphoma: report of a case highlighting the importance of attention to basic cytomorphological details and clinico-pathological correlation

Abstract Distinction between a cutaneous lymphoma and pseudolymphoma can sometimes be exceedingly difficult. An increasing number of reactive inflammatory conditions with large numbers of CD30-positive atypical cells are being recognized. Some of these cases may be potentially misdiagnosed as a cutaneous lymphoma (CD30-positive lymphoproliferative disorder) on morphology alone. Cutaneous herpesvirus infection, particularly when developing in immunosuppressed individuals, can present as a pseudolymphoma with numerous CD30-positive blastoid cells. A careful search for viral cytopathic changes in the epidermis and adnexal epithelium, along with correlation with the overall clinical picture and appropriate ancillary investigations, may be necessary to establish a correct diagnosis.