Leptomeningeal dissemination of a low-grade lumbar paraganglioma: case report

Abstract

Leptomeningeal dissemination of paraganglioma is rare, with only 2 prior cases in the literature. The authors present the case of a metastatic low-grade lumbar paraganglioma via leptomeningeal dissemination. This report emphasizes the utility of 3,4-dihydroxy-6-¹⁸F-fluoro-l-phenylalanine (¹⁸F-FDOPA) PET scanning for diagnosis, as well as the combination of radiation therapy and alkylating chemotherapeutic agents for the treatment of this rare phenomenon. The patient was a 61-year-old woman who presented with low-back pain and was found to have an isolated L-3 intrathecal tumor on MRI. Sixteen months after gross-total en bloc resection of the paraganglioma, the patient again became symptomatic with new neurological symptoms. MRI findings revealed enhancing leptomeningeal nodules throughout the spine. ¹⁸F-FDOPA PET/CT scanning was used to confirm the diagnosis of disseminated paraganglioma. Intrathecal thiotepa, radiation therapy, and systemic therapy with capecitabine and temozolomide have been used sequentially over a 2-year period, with each able to stabilize tumor growth for several months. The authors also summarize the 2 other reports of leptomeningeal dissemination of paragangliomas in the literature and compare the course and management of the 3 cases.

Keywords: 18F-FDOPA = 3,4-dihydroxy-6-18F-fluoro-l-phenylalanine; 18F-FLT = 3′-deoxy-3′-18F-fluorothymidine; lumbar; metastasis; neuroendocrine tumor; oncology; paraganglioma; spinal neoplasm.

Figure 1

Hematoxylin and eosin (H&E) staining of the tumor reveals nests of cells (the classic Zellballen pattern) consisting of small ovoid nuclei and eosinophilic cytoplasm separated by thin, fibrovascular septae (H&E × 200 - Figure 1a (left)). Higher power reveals the bland, stippled chromatin pattern and scattered nucleoli (H&E × 400 - Figure 1b (right)).

Figure 2

The tumor is positive by immunohistochemical staining for non-specific enolase (NSE × 400 – Figure 2a (left)) and synaptophysin (synaptophysin × 400 – Figure 2b (right)).

Figure 3

Sagittal T1 post-contrast images depict an enhancing mass at presentation (left) and enhancing recurrence at 17 months in the lumbar spine (middle), including dependently in the inferior thecal sac, in addition to post-operative changes from prior mass resection. (Right) Sagittal T1 post-contrast image depicting thoracic metastases at 17 months.

Figure 4

Sagittal CT Scan (left) compared with ¹⁸F-FDOPA PET/CT uptake scan (right) demonstrating recurrence of paraganglioma at 6 months.