Malignant Melanoma

A 25 year old man, known case of Hodgkin lymphoma since 2002 (autologous BMT), complain from tumor like purple and non tender lesion in dorsal left leg

Differential diagnosis: lymphoma, angiosarcoma & other vascular tumors and melanoma

Left leg biopsy performed; the section showed skin tissue with marked infiltration of highly atypical cells in dermis. The invade surface epithelium (or arise from surface epithelium?) tomural necrosis was seen focally, some nesting were seen in the tumoral cells especially in the upper dermis

Diagnosis: malignant neoplasm, undifferentiated

1-amelanotic melanoma

2-high grade lymphoma

IHC requested; S100: strongly positive in infiltrated cells, HMB 45: non specific immunoreactivity

LCA, CD20 & CD45R/O were negative in infiltrated cells