The below case and findings were published in the Journal of Dermatological Treatment.
BAP1 Tumor Predisposition Syndrome (BAP1-TPDS) is very rare, and its pattern was only recently classified in 2011. This syndrome is associated with several aggressive cancers, most commonly: uveal melanoma, malignant mesothelioma, renal cell carcinoma and cutaneous melanoma. It was first observed in families who had a disproportionate co-occurrence of both uveal melanoma and malignant mesothelioma. A common first finding in this syndrome are benign skin tumors called BAP1-Inactivated Melanocytic Tumors or BIMTs. These typically occur in the second decade of life, and are seen in approximately 80% of patients with BAP1 Tumor Predisposition Syndrome. BIMT lesions present as a possible marker which should prompt further investigation. On their own, these lesions are considered benign, however, in the context of more than two BIMTs or a prior personal/family history of BAP1-TPDS related cancers prompt genetic testing is indicated.
A patient was seen in dermatology clinic presenting with a benign appearing spot at her forehead hairline. This was biopsied and found to be a BAP-1 inactivated melanocytic tumor. This on its own is typically a benign finding, however, on further investigating the patient’s family history it was discovered that there was a significant history of eye and skin melanomas. This patient was advised to seek genetic testing, and initiate at least yearly ophthalmologic examination, regular skin checks, and consider screening for mesothelioma/kidney cancers.
Per our review of the literature – genetic evaluation should be encouraged in patients presenting with multiple BIMTs or a new BIMT with significant family history of BAP1-TPDS related cancers. If positive for a germline BAP1 mutation, cancer surveillance should be recommended for early diagnosis and intervention. Genetic cancer syndromes often have early manifestations that serve as harbingers. BIMTs are a possible harbinger of, the relatively unknown, BAP1-TPDS and should not be ruled out as benign without clear investigation. If found to have a BIMT and then BAP1-TPDS, patients could benefit significantly from cancer surveillance for earlier diagnosis, management, and improved outcomes in BAP1-TPDS related cancers.