EPCO-59. FIRST CASE REPORT OF COMBINED GERMLINE NF1 AND BRCA2 MUTATIONS PRESENTED WITH NEUROFIBROMAS AND LIPOMATOSIS

Abstract Both Neurofibromatosis type 1(NF1) and BRCA2 are common tumor suppressor genes, with mutations in each associated with genetic tumor syndromes. However, it is extremely rare to observe two different germline mutations in one patient. To the author’s knowledge, this is the first case report of a patient with germline mutations in both pathological NF1 and BRCA2 genes. We report a 41-year-old male patient with neurofibromas and lipomatosis. The patient with known family history of NF1, was diagnosed with NF1 after skin biopsy at 28 years old. At 40 years old, he underwent resection of a large intrathoracic neurofibroma. For genetic confirmation, next generation sequencing test was performed on both the intrathoracic neurofibroma tumor sample and saliva sample, revealing unexpected pathological germline mutation in both NF1 and BRCA2 genes. Consequently, the patient underwent resection of multiple lesions in the chest, abdomen, and upper extremities due to concern for potential breast cancers, and pathology of these lesions predominantly showed lipomas and one angiolipoma. Patient has family members with NF1 including a maternal aunt, a maternal cousin, and one son. However, there is no family history of lipomatosis or cancers commonly associated with BRCA2 mutation such as breast, ovarian, pancreatic, or prostate cancer. While lipomas are reported in patients with NF1, it is unusual that patient does not have typical café-au-lait spots or multiple neurofibromas but instead has multiple lipomas. This unusual presentation may be related to his unique genetic condition involving germline mutations in two tumor suppressor genes. Long term follow-up with screening tests for known tumors associated with each genetic mutation will be essential.