Radiological and pathological findings of a metastatic composite paraganglioma with neuroblastoma in a man: a case report

Abstract

Introduction: Composite tumors of the adrenal medulla or paraganglia are extremely rare and present a diagnostic dilemma. These tumors consist of a neuroendocrine component mixed with a neural component.We describe the imaging characteristics together with the corresponding pathological findings of a composite tumor. Apart from any component-specific imaging findings, the hallmark of this entity is the presence of histologically distinguishable components.

Case presentation: A 61-year-old Caucasian man was referred to our hospital due to a suspect lesion found on chest computed tomography carried out for unclear thoracic pain. An abdominal computed tomography scan and ultrasound examination detected a retroperitoneal tumor comprising two different tumor components. Twenty-four-hour urine revealed high levels of normetanephrine, characteristic of a neuroendocrine tumor. An octreoscan prior to surgical procedures revealed multiple osseous and intra-hepatic metastases. The final histopathological workup revealed a composite paraganglioma with neuroblastoma. Our patient died ten months after the initial diagnosis from tumor-associated complications.

Conclusions: Composite paragangliomas with neuroblastoma are rare tumors of the retroperitoneum. Such tumors should be considered in the differential diagnosis of retroperitoneal masses.

Figure 1

Ultrasound image of the composite paraganglioma. (A) The caudally located neuroblastoma. (B) The hypervascularized paraganglioma (arrowhead) and shows the delineation from the neuroblastoma (asterisk).

Figure 2

(A) Axial and (B) coronal multi-planar reformation showing the composite paraganglioma (arrowhead) including the hyperdense paraganglioma with cystic lesions and the hypodense neuroblastoma component compressing the right ureter leading to delayed enhancement of the right kidney (asterisk). The duodenum is displaced (arrow).

Figure 3

(A) A macroscopic image of the composite paraganglioma. The well delineated cranial part (right side) of the tumor with cysts, necrosis and hemorrhages represents the paraganglioma. The less well demarcated, white-gray-tan colored solid part of the tumor (left side) represents the caudally located neuroblastoma component. (B) The microscopic image demonstrates the two histological components of the tumor delineated by fibrous tissue. The paraganglioma (upper part) appears lighter in the low power view corresponding to more abundant cytoplasm of the tumor cells that are arranged in the typical Zellballen pattern (inlet A). The neuroblastoma (lower part) appears bluish corresponding to the densely packed small blue round cells with scant cytoplasm (inlet B). In the fibrous band between both components the vascular invasion of the neuroblastoma can be appreciated.