The exact cause of Spitzoid tumours of uncertain malignant potential (STUMP) is not well understood, but they are thought to arise from a combination of genetic, epigenetic, and environmental factors.
The diagnosis of STUMP is made through careful clinical examination, imaging studies, and tissue biopsy. The biopsy will typically reveal a spindle cell or epithelioid cell proliferation, with moderate atypia and no mitotic activity.
Differential diagnoses for STUMP include malignant melanoma, spindle cell melanoma, and desmoplastic melanoma.
STUMP is typically treated with wide local excision or Mohs surgery. In cases where the tumour is in a difficult to excise area, radiation therapy may be used.
The prognosis for patients with STUMP is good, with long-term survival rates typically exceeding 95%. However, it is important to monitor for recurrence due to the tumour’s uncertain malignant potential.