A Wolf in Sheep's Clothing: Collision of Melanoma and Keratoacanthoma

Matthias Walther, Sandra Falkvoll, Sebastian Leibl
2021 Dermatopathology  
Collision tumors consisting of melanoma and squamous cell carcinoma are very rare. We present the case of a deceptive hyperkeratotic nodule on the forearm of a 72-year-old woman, which clinically appeared to be a squamous cell carcinoma, keratoacanthoma type. Histological examination surprisingly revealed a coexisting epithelioid melanoma. Thus, this case report shows the importance of an early histopathological and immunohistochemical workup to prevent unnecessary diagnostic and therapeutic delay with negative effects on prognosis.
doi:10.3390/dermatopathology8030030 pmid:34287287 fatcat:arg3iql63na55nug4y4ksy7hoq