Chondroid atypical spitzoid melanocytic tumor

Area of Science:

• Dermatopathology
• Oncology
• Melanoma Research

Background:

• Chondroid stromal change is an exceptionally rare finding in melanocytic nevi.
• Spitz tumors are a group of melanocytic neoplasms with specific diagnostic challenges.
• Atypical presentations require thorough clinicopathological and molecular evaluation.

Observation:

• A case of a severely atypical symmetrical Spitz tumor on the right arm of a 24-year-old man is presented.
• The tumor exhibited features of maturation alongside occasional mitotic figures.
• Melanocytes were observed to be intermingled with a cartilaginous stroma.

Findings:

• The Ki67 proliferative index was 5%.
• Immunohistochemistry revealed weak positivity for p16 and negativity for BRAF/V600E.
• BAP1 expression was preserved, and PCR for the Myriad myPath Melanoma test was negative.

Implications:

• This case highlights the rare occurrence of chondroid stroma in Spitz tumors.
• Understanding the molecular profile (p16, BRAF/V600E, BAP1) is crucial for differential diagnosis.
• Such findings contribute to the literature on rare melanocytic neoplasms and their diagnostic workup.