Contributed by Sourav Ray MD1, Drazen M Jukic MD PhD1, Juan Rosai MD2
1University of Pittsburgh Medical Center, Departments of Pathology and Dermatology, Pittsburgh PA, USA.
2Centro Consulenze Anatomia Patologica Oncologica Centro Diagnostico Italiano (CDI), Milan, Italy
Published on line in December 2005
An elderly gentleman presented with a plaque-like crusted lesion of his right temple in conjunction with supraclavicular lymphadenopathy. The lesion was excised and excisional lymph node biopsy was performed.
Low power examination revealed an exophytic vaguely papillomatous proliferation of both basaloid and squamoid cells in the epidermis with distinct nodular and basaloid regions (Pictures 1, 2, 3 and 4). Also conspicuous from low power were sheets of dark blue discohesive cells in close approximation to the proliferative portions of the epidermis (Pictures 7, 8 and 10).
High power examination of the lower portions of the epidermis revealed basal palisading with retraction in some areas (Pictures 5 and 9) and squamoproliferative zones with moderate to marked cytologic atypia (Picture 6, Pictures 26 and 27). The discohesive blue cells were markedly atypical with a high mitotic and apoptotic rate. They were growing in sheets and thin trabeculae and occasionally demonstrated nuclear smudging (Pictures 11, 12, 13, 14, 15, 16 and 17).
The excised lymph nodes were enlarged and partially effaced by a homogenous proliferation of lymphocytes that exhibited pale zones on low power examination (Pictures 18 and 23). Under high power examination larger 'prolymphocytes' were seen interspersed in these pale regions (Picture 24). Also evident was a population of atypical discohesive blue cells filling the subcapsular sinus in one of the nodes (Pictures 18, 21, 22 and 25). This metastatic population was remarkably similar to the discohesive small blue cell population encountered in the epidermis when examined under higher power (Picture 19).
A few immunostains were performed and are reported herein. Cytokeratin AE1/3 cocktail was positive in the basaloid epidermal portions (AE13). Cytokeratin 20, though very focal was positive in some of the atypical discohesive cells (CK20); 'dot-like' positivity was not encountered. More striking however, was the positivity for NSE, NCAM, synaptophysin, and chromogranin in the small blue cell population (NSE, NCAM, synaptophysin, chromogranin). S100 was negative in all lesional cells but highlighted some dendritic cells (S100).
What is your diagnosis? What underlying disease does this elderly patient already have?