Abstract

A 45-year-old female with a past medical history of contact dermatitis, obstructive sleep apnea, iron deficiency anemia, and morbid obesity presented with a 5 mm firm pink papule at the right nasal ala. The lesion had been growing for a couple of months but was otherwise asymptomatic. Patient specifically denied any pain, itching or bleeding. Sections of the specimen reveals a well-circumscribed lesion with spindle-shaped to ovoid neoplastic cells on a background of fibromyxoid stroma. Furthermore, clear formation of bone is identified at the center and is interspersed with the spindle cells. The spindle cells reveal low-grade atypia and rare mitoses. Consistent with the stromal myxoid component, the Alcian blue stain was positive. Immunohistochemical staining reveals negative staining with antibodies to AE1/AE3, MITF, pan-cytokeratin, S-100 protein, desmin, CD10, CD68, and neuron-specific enolase (NSE). Weak positive staining was seen with smooth muscle actin (SMA). The combination of histopathologic and immunohistochemical features seen in the case is not characteristic of any well established entity. Bone formation is a truly unusual finding. The TNC-PDGFD fusion appears to be novel, without having been previously reported in the literature. The histopathologic differential diagnosis for this could include an ossifying fibromyxoid tumor, myoepithelioma, and neurothekeoma. But we believe that the best diagnosis is that of a spindle cell neoplasm with a TNC-PDGFD novel gene fusion.

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