Abstract
BACKGROUND: Multiple primary tumors, especially quadruple primary neoplasms is extremely rare. Fibrous dysplasia (FD), osteosarcoma (OS), and giant cell tumor of bone (GCTB) are three bone tumors with low incidence while primary pulmonary meningioma is a rare disease. In this case report, we present a unique synchronous occurrence of these four separate pathological conditions. CASE PRESENTATION: A 53-year-old male previously underwent resection of OS of fifth rib and FD of eighth rib 1 year ago. Recently, a discontinuous pain at right knee developed. Serial X-ray films showed a progressively pure osteolytic lesion of proximal tibia which extended gradually. The incisional biopsy revealed that this tumor was confirmed as GCTB, and the tumor was successfully managed by extensive curettage and bone cement filling. The diagnosis of GCTB was re-confirmed by the postoperative histopathologic examinations. High-throughput sequencing from the GCTB exhibited a somatic mutation of H3.3A (G35W exon2). Germline testing revealed a germ-cell variant in gene of BRCA2 (exon 8 V220Ifs*4). CONCLUSIONS: This is a unique case with quadruple primary tumors. Germline mutation in gene of BRCA2 may be associated with the occurrence of multiple primary tumors in this patient.