275 Metastatic Anaplastic Oligodendroglioma to the Scapula—A Rare but Real Diagnostic Challenge

• Published in: American journal of clinical pathology Vol. 149; no. suppl_1; p. S117
• Main Authors: Appleford, Colin, Donev, Kliment, Qu, Zhenhong
• Format: Journal Article
• Language: English
• Published: US Oxford University Press 11-01-2018
• Subjects: Biopsy; Bone lesions; Brain cancer; Case reports; Cell proliferation; Frontal lobe; Glial fibrillary acidic protein; Humerus; Hybridization; Magnetic resonance imaging; Medical diagnosis; Metastases; Metastasis; Mitosis; Oligodendroglioma; Scapula; Seizures; Temozolomide; Tumor cells
• ISSN: 0002-9173; 1943-7722
• DOI: 10.1093/ajcp/aqx123.274

Abstract
Extracranial metastasis of an oligodendroglioma is exceedingly rare. We report a case of a metastatic anaplastic oligodendroglioma to the scapula. The patient was a 44-year-old man who was found to have a right frontal lobe mass during the work-up for episodes of seizures. Biopsy of the mass revealed an anaplastic oligodendroglioma with 1p/19q codeletion. The mass was resected and the patient was treated with temozolomide. Subsequently, the patient had three intracranial recurrences, three, five, and six years after the original resection. Twelve years after his initial diagnosis of oligodendroglioma, he presented with shoulder pain. An MRI demonstrated a large heterogeneously enhancing mass within the body of the left scapula extending into the glenoid and coracoid processes, as well as extending across the glenohumeral joint and involving the proximal humerus. Extensive anterior and posterior extraosseous extension was also present. Biopsy of the mass revealed neoplastic proliferation of cells with round nuclei and frequent mitoses, morphologically very similar to the patient’s prior anaplastic oligodendroglioma in the right frontal lobe. Tumor cells were positive with GFAP and S100 immunostains, and IDH1-R132H mutation was detected by immunostain. In situ hybridization study revealed 1p/19q codeletion in the neoplastic cells. Overall, the findings were consistent with metastatic anaplastic oligodendroglioma.
Metastatic oligodendrogliomas are rare and only a handful of cases have been reported in the literature with bone being the most frequent metastatic site. It is important to be aware of the possibility of extracranial metastasis of oligodendroglioma when diagnosing bone lesions because it can represent a serious diagnostic challenge if clinical history is unknown. Knowledge of prior patient’s clinical history aids tremendously in diagnostic accuracy of these cases.