This transcript details the histopathological examination of a skin biopsy, initially queried as a benign skin tag or nevus, which is ultimately diagnosed as a Neurofibroma. The diagnosis is confirmed by the presence of haphazard, bland spindle cells exhibiting characteristically "buckled" or "bent" nuclei—a key cytological feature of schwann cells. The specimen also contains scattered mast cells and small nerve bundles. A significant teaching point addresses the presence of scattered pleomorphic, multinucleated "floret cells" within the tumor. Although visually atypical, these features confirm the neurofibroma remains benign, though their presence may prompt consideration of an association with Neurofibromatosis Type 1 (NF1). The video concludes with a brief, unrelated observation of a lymphatic channel valve.
Neurofibroma Histopathology: Identifying Schwann Cells and Benign Atypia
0:14 - 0:35 Initial Findings: The specimen, a fleshy polyp, was initially clinically suspected to be a skin tag or nevus, but microscopic examination revealed a spindle cell lesion set in a background of pink collagen.
0:54 - 1:26 Key Diagnostic Feature: The spindle cells are identified as schwann cells. A characteristic cytological feature is the nuclei appearing "buckled" or "bent" (likened to a popped soda can tab), distinguishing them from other spindle cell types.
1:30 - 2:23 Confirming the Diagnosis: The presence of schwann cells, small nerve fibers ("nerve twigs"), fibroblasts, perineurial cells, and scattered mast cells (described as "fried egg" cells) confirms the diagnosis of Neurofibroma.
2:33 - 2:55 Focus on Pleomorphism: The lesion contains unusual cells, including pleomorphic and multinucleated cells, specifically "floret cells" (nuclei arranged in a ring or flower-like pattern).
3:19 - 3:39 Key Takeaway on Atypia: Despite the visually strange appearance of the floret cells and general pleomorphism, the neurofibroma remains totally benign. These findings, however, may be more common in patients with Neurofibromatosis Type 1 (NF1).
3:45 - 4:10 Bonus Observation: The speaker points out a well-sectioned lymphatic channel featuring a valve, a relatively rare and interesting histological finding.