Melanoma developing in a nevoid melanocytoma with myxoid changes: a case report |
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| Authors: | Andrew S Kao Kayla St Claire Lisa M Bedford Darius R Mehregan Aleodor A Andea David Kouba |
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| Affiliation: | 1. Wayne State University School of Medicine, MI, USA ; 2. Department of Dermatology, Wayne State University, MI, USA ; 3. Department of Pathology and Dermatology, University of Michigan, MI, USA ; 4. Facial Plastics and Dermatology, The Toledo Clinic, OH, USA |
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| Abstract: | Nevoid and myxoid melanoma are rare variants of melanoma; association of the two is a unique finding. Nevoid melanoma is characterized by morphologic resemblance to a nevus, whereas myxoid melanoma demonstrates a basophilic mucinous matrix. We present an atypical case of a melanoma progressing from a nevoid melanocytoma with myxoid changes. A 78-year-old female presented with a pigmented growth on her right thigh. Biopsy demonstrated a biphenotypic melanocytic proliferation composed of a nodule showing epithelioid melanocytes with enlarged nuclei, prominent nucleoli, lack of maturation, and abundant amphophilic cytoplasm with a rare mitotic figure. These findings were suggestive of melanoma along with a nevoid dermal component and myxoid stroma. FISH testing revealed a homozygous loss of 9p21 in the atypical component. SNP-microarray from the nevoid component demonstrated three abnormalities including a gain of whole chromosome 8, as well as loss of a copy of nearly an entire chromosome 9 and 16q most consistent with a melanocytoma. |
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| Keywords: | Myxoid melanoma nevoid melanoma malignant melanoma melanocytoma |
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