A case of paraganglioma of the retroperitoneum

Abstract

Background : Paraganglioma (PGL) is a relatively rare neuroendocrine tumor that usually arises in the skull, peritoneal aorta, or urinary bladder. In this study, we report a case of PGL that was located in the retroperitoneum.

Case : A 40-year-old female patient was referred to our hospital with a history of muscle spasms throughout the body and abnormally elevated creatine kinase levels in the blood. Abdominal imaging revealed a mass around the duodenum, and endoscopic ultrasound-guided fine-needle aspiration cytology showed loose agglomerates of tumor cells. The cellular cytoplasm was lacy and pale and had unclear boundaries. The nuclear-cytoplasmic ratio was generally low, and the nuclei were round-to-oval shaped, varying in size. The nuclear chromatin varied from fine to coarse, and there were some cells with large nuclei. Histopathological examination of the excised surgical specimen showed alveolar-shaped cells with basophilic granular cytoplasm in a Zellballen pattern, surrounded by vascular stroma. Immunohistochemistry showed positive staining of the tumor cells for chromogranin A, and positive staining of the sustentacular cells for S-100. Based on these findings, we diagnosed the tumor as a PGL.

Conclusion : In the presence of a variegated cell cytology, the possibility of PGL should be borne in mind.