Giant Pediatric Rhabdoid Meningioma Associated with a Germline BAP1 Pathogenic Variation: A Rare Clinical Case.

BACKGROUND: Rhabdoid meningiomas are rare World Health Organization grade 3 tumors that tend to follow an aggressive course, with an increased likelihood for local recurrence, remote metastasis, and cerebrospinal fluid dissemination. Genetic testing has found certain genes associated with reduced time to tumor recurrence. BAP1 (BRCA1-associated protein 1) is a tumor suppressor gene that is associated with multiple tumors, including rhabdoid meningiomas.

CASE DESCRIPTION: We present a case of a pediatric patient who presented with a rhabdoid meningioma occurring in the right tentorium and invading multiple venous structures, including the right jugular vein. The patient underwent 5 separate operations for management of this tumor. The first surgery was an intracranial tumor debulking with reconstruction of venous structures. Postoperatively, the patient was unable to have the ventricular catheter removed and underwent placement of a ventriculoperitoneal shunt. Significant recurrence of the intracranial portion of tumor was found during preoperative imaging for her second stage procedure. She underwent a second craniotomy for resection of the tumor. Her postoperative magnetic resonance imaging showed significant residual tumor and the patient therefore underwent a third craniotomy for total tumor resection, which involved reconstruction of the superior sagittal sinus. She did well after this surgery, with no new neurologic deficits. Her final operation involved resection of the residual tumor in the neck and chest by both otolaryngology and cardiothoracic surgery. This surgery involved opening the jugular vein and resecting residual tumor from the intima. Pathologic results from all surgeries were consistent with rhabdoid meningioma; however, the tissue from the biopsy and first craniotomy lacked the high-grade features that were found on subsequent resections. Genetic analysis found loss of both BAP1 tumor suppressor genes. Peripheral blood testing showed that this patient was a germline carrier of a pathogenic BAP1 variant.

DISCUSSION: Pediatric rhabdoid meningiomas represent a rare disease and are found on recurrent tumors in conjunction with lower-grade meningioma disease. Our patient presented with what was initially believed to be a low-grade meningioma with rhabdoid features, which then transformed into a World Health Organization grade III rhabdoid meningioma on recurrence. This tumor was discovered to have a biallelic loss of BAP-1 mutation and the patient was found to have a germline mutation in 1 of her BAP-1 alleles. Germline mutations in BAP-1 are associated with a cancer syndrome that involves uveal and cutaneous melanoma, malignant mesothelioma, atypical Spitz tumors, and clear-cell renal cell carcinoma. Patients with this mutation are encouraged to undergo annual eye examinations starting at the age of 11 years. The BAP-1 tumor predisposition syndrome is most commonly an inherited mutation associated with incomplete penetrance and variation with nonoverlapping tumor types.

CONCLUSIONS: Rhabdoid meningiomas are unlikely to be found in children and have a high rate of local recurrence. Gross total resection has to be balanced with risk of postoperative deficit. Genetic testing of this rare entity should be performed to identify any hereditary germline mutations.