Unexpected Circulatory Collapse After Cardiac Paraganglioma Resection: Rescue With Intra-Aortic Balloon Pump and Extracorporeal Membrane Oxygenator

Cardiac paragangliomas: A case series with clinicopathologic features and succinate dehydrogenase B immunostaining

Cardiac paragangliomas (PGs) are very rare tumors that comprise less than 1% of all cardiac tumors. PGs can occur sporadically, but inherited syndromes may also play a role in the development of PGs. Approximately one-third of PGs are associated with mutations in the succinate dehydrogenase (SDH) complex, specifically SDHB, as part of syndrome-associated PGs or sporadic PGs. SDH mutations have been assessed by SDHB immunohistochemistry, as negative staining indicates a high likelihood of mutation in PGs in other sites, but not in cardiac PGs. This study aims to evaluate the clinical and pathologic characteristic of cardiac PG cases and assess the expression of SDHB by immunohistochemistry. A retrospective chart analysis of 10 patients with cardiac PG was performed to assess the patient age, sex, size, site of the tumor, and clinical symptoms. Histologically the tumors showed the classic pattern of nested tumor cells surrounded by sustentacular cells. Immunohistochemistry for SDHB was performed in five cases. One case showed a complete absence of SDHB immunohistochemical staining and the others showed staining ranging from a weak-to-strong granular cytoplasmic staining pattern. We conclude that SDHB immunostaining is cost-effective in identifying cases with SDH mutation. It is recommended to assess SDH mutation in patients with cardiac PG to predict the aggressive behavior that has been reported by previous studies from PGs of other sites.

Unusual cardiac paraganglioma mimicking an atypical carcinoid tumor of the lung

We present a case of unusual cardiac paraganglioma (PG) initially misdiagnosed as atypical carcinoid tumor of the lung and discuss key clinical and pathologic characteristics that guide surgical management of these rare chromaffin cell tumors. A 64-year-old female with persistent cough and back pain was found to have a 4 cm × 3 cm mass abutting multiple cardiopulmonary structures. A biopsy was performed at an outside institution and pathology reported "atypical neuroendocrine carcinoma, consistent with carcinoid". The patient was transferred to our institution and pericardial resection with right pneumonectomy was performed to excise the tumor. Histology of the mass was that of PG with multiple ethanol embolizations. Immunohistochemical examination revealed that type I (chief) cells were positive for neuroendocrine markers (chromogranin A and synaptophysin), while type II (sustentacular) cells were positive for S100. There was no evidence of atypical carcinoid tumor in the lung. PG is an entity of chromaffin cell tumors that often affects the adrenal glands and carotid body. PG rarely occurs in the thoracic region, accounting for just 1-2% of all PG. Proper diagnosis of cardiac PG is challenging owing to its rare prevalence, subtle symptoms of presentation, and the neuroendocrine histopathological features it shares with atypical carcinoids. These tumors are typically benign and are best treated by surgical resection. Our report examines the approach to appropriate diagnosis of cardiac PG vs. atypical carcinoid, preoperative management, and surgical treatment by describing successful resection through thoracotomy without the use of cardiopulmonary bypass.