Primary Pineal Melanoma With Leptomeningeal Carcinomatosis

Pineal region tumors commonly present with features of increased intracranial pressure such as headache, nausea, and vomiting due to obstructive hydrocephalus. Parinaud syndrome is also common.

Poster 29 Primary Pineal Melanoma with Leptomeningeal Carcinomatosis Ashley Aaroe1, Isabella Glitza Oliva1, Nagham Al-Zubidi1, Marc-Elie Nader1, Diana Kaya1, Sherise Ferguson1, Chenyang Wang1, Gregory Fuller1, Rebecca Harrison1 1 MD Anderson Cancer Center, Houston, Texas, USA Introduction: Pineal region tumors commonly present with features of increased intracranial pressure such as headache, nausea, and vomiting due to obstructive hydrocephalus. Parinaud syndrome is also common. Description of Case(s): A 62-year-old man presented with five months of rapidly progressive bilateral hearing loss and intermittent binocular diplopia. Examination revealed light-near dissociation with minimal retraction nystagmus on upward gaze consistent with Parinaud syndrome. Audiometry showed moderate to severe bilateral sensorineural hearing loss. Contrast-enhanced MRI of the brain demonstrated an intrinsically T1 hyperintense contrast-enhancing infiltrative mass in the pineal region extending into the midbrain and thalami with evidence of leptomeningeal spread. Other diagnostic imaging was unrevealing. CSF sampling was deferred. He underwent an endoscopic biopsy and intraoperatively black material was seen lining the ventricles. Pathology revealed a high-grade pigmented epithelioid neoplasm with strong expression of markers HMB45, MART1 and tyrosinase. The integrated diagnosis was primary pineal melanoma. He was treated with one cycle of ipilimumab and nivolumab, followed by whole brain radiation with concurrent temozolomide chemotherapy. Conclusions, including unique features of the case(s): Germ cell tumors are the most common pathologic entity in the pineal region, followed by pineal parenchymal tumors [1,2]. As hydrocephalus is often observed, the risks and benefits of CSF sampling by lumbar puncture must be weighed. Primary pineal melanoma is an extraordinarily rare entity, estimated to account for 3.6% of all primary central nervous system melanomas, which themselves only account for approximately 0.07% of intracranial neoplasms [3]. It is thought to arise from melanocytes in the pia mater of the pineal interlobular septa, as neural crest cells are known to migrate into the leptomeninges during development [4]. The optimal treatment is unknown, but commonly these tumors are treated with surgical resection, radiation, and either chemotherapy or immunotherapy. Some patients have received targeted therapy (such as vemurafenib in patients with BRAF V600E mutation) with varying degrees of success. [5] References: [1] Al-Hussaini M, Sultan I, Abuirmileh N, Jaradat I, Qaddoumi I. Pineal gland tumors: experience from the SEER database. J Neurooncol. 2009;94(3):351-358. doi:10.1007/s11060-009-9881-9 [2] Dahiya S, Perry A. Pineal tumors. Adv Anat Pathol. 2010;17(6):419-427. doi:10.1097/PAP.0b013e3181f895a4 [3] Biswas A, Chaudhari PB, M SK, et al. Primary pineal malignant melanoma - illustrated review. Turk Neurosurg. 2015;25(2):201-209. doi:10.5137/1019-5149.JTN.6568-12.1 [4] Wendel C, Kaech DL, Woodtli M. Primary Malignant Melanoma in the Pineal Region: Case Report and Literature Review. J Neurol Surg A Cent Eur Neurosurg. 2018;79(4):344-352. doi:10.1055/s-0038-1639504 [5] Jetschke K, Viehweger H, Freesmeyer M, Warnke JP, Mawrin C. Primary pineal malignant melanoma with B-Raf V600E mutation: a case report and brief review of the literature. Acta Neurochir (Wien). 2015;157(7):1267-1270. doi:10.1007/s00701-015-2427-3 Keywords: tumors, neuroimaging, neuro-ophth & systemic disease (eg. MS, MG, thyroid) Financial Disclosures: The authors had no disclosures. Grant Support: None. Contact Information: Ashley Aaroe, [e-mail] 2021 Annual Meeting Syllabus | 111