Endocrine Abstracts

Background: Neuroblastomas are malignant tumors that arise from sympathetic plexus or adrenal medulla. Their clinical behavior can range from spontaneous regression to aggressive disease. Like paragangliomas, they have the capacity to secrete catecholamines and to express somatostatin receptors, which is important for diagnostic and treatment purposes. However, the differential diagnosis with paraganglioma can be challenging. We present a case of a catecholamine-producing tumor whose final diagnosis was not straightforward.

Clinical case: A 24 years female presented with dorsal, lumbar and pelvic pain, pelvic paresthesia, dysuria and fever in the last 2 months. The complementary exams showed elevated inflammatory parameters, normocytic normochromic anemia and a right pleural effusion. Antibiotic therapy and several exams were performed.

The computerized tomography scan (CT) revealed several soft tissue lesions (the 2 dominant ones located in left paravertebral areas): D3-D6 measuring 48×44×32 mm and D8-12 with 46×40×46 mm, sacred vertebrae (S1−S4) and iliac bones. The magnetic resonance confirmed well defined lesions and hyperintense in T2. A CT-guided biopsy of both dominant lesions was made, suggesting a paraganglioma positive for S-100, chromogranin and synaptophysin in immunohistochemistry in the superior lesion (D3-D6) and a schwannoma in the inferior (D8-12). No immediate complications of the procedure occurred. At that point she was referenced to our endocrine oncology center. It was required a positron-emission tomography (PET) with 68Ga-dotanoc, which showed hyperexpression of somatostatin receptors in the paravertebral lesions (SUVmax 5.2 in the superior lesion and 12.8 in the inferior), in the sacrum (SUVmax 6.3), in the fourth left rib (SUVmax 4.8) and right scapula (SUVmax 7.5). The total urine metanephrines were high (38.4 mg/24 h, normal range (NR)<1) and also the vanillylmandelic acid (86.6 mg/24 h, NR<14) and chromogranin A (546 ng/ml, NR<100). She started phenoxybenzamine and palliative treatment. A PET-18Fluorodeoxyglucose was performed showing extensive metastasis in bones, muscles and lymph nodes. At that time a review of the previous histology was made: it was diagnosed a poorly differentiated neuroblastoma and a ganglioneuroma in the superior and inferior paravertebral lesion, respectively. An osteomedullary biopsy was than performed and revealed neuroblastoma infiltration in the medulla. She started chemotherapy with vincristine, etoposide and carboplatin. During chemotherapy she developed dural metastases and she is being treated with cranial radiotherapy at this point.

Conclusion: This case illustrates the importance of considering the neuroblastoma in the diagnostic workup of apparently metastatic paraganglioma in young adults, even when catecholamines are produced, 68Ga-dotanoc uptake is present and immunohistochemistry profile is compatible.