Benign splenic lesions in BAP1-tumor predisposition syndrome: a case series

Abstract

BAP1-Tumor Predisposition Syndrome (TPDS) is caused by germline variants in BAP1 and predisposes to solid tumors. After observation of a radiologically malignant-appearing splenic mass with benign pathology in a patient with BAP1-TPDS, we sought to retrospectively characterize splenic lesions in individuals with BAP1-TPDS seen at a comprehensive cancer center. A dedicated radiology review for splenic abnormalities was performed. We identified 37 individuals with BAP1-TPDS, 81% with a history of cancer. Of 33 individuals with abdominal imaging, 10 (30%) had splenic lesions, and none were shown to be malignant on follow-up. Splenectomy in an individual with suspected splenic angiosarcoma showed a benign vascular neoplasm with loss of nuclear staining for BAP1 in a subset of cells. Benign splenic lesions appear to be common and potentially BAP1-driven in individuals with BAP1-TPDS; confirmation of these findings could lead to more conservative management and avoidance of splenectomy.

Fig. 1. Radiographic and pathologic examples of benign splenic lesions in patients with BAP1 germline variants.

A–D MRI and PET imaging in a patient with radiological features suggestive of a malignant splenic lesion, favoring angiosarcoma. E Gross and microscopic images of the resected splenic vascular lesions seen in images (A–D). F CT and MRI images of another patient with well-defined and isodense splenic lesion after 6 years of follow-up.