Malignant pheochromocytoma secreting vasoactive intestinal peptide and response to sunitinib: a case report and literature review

VIP-secreting Pheochromocytoma: A Case Report and Review of Literature

Objective

To describe a case of composite vasoactive intestinal peptide (VIP)-secreting pheochromocytoma and review literature to provide insight into the various presentations and potential management of these rare tumors.

Case Report

A 64-year-old male patient presented with hypertensive emergency and coronary demand ischemia with development of watery diarrhea, hypokalemia, and achlorhydria syndrome. Serum and urine studies demonstrated elevated metanephrine and VIP levels. Definitive surgical resection resolved symptoms and normalized laboratory values. Pathologic examination of the specimen revealed pheochromocytoma with a Pheochromocytoma of the Adrenal gland Scaled Score of 4 and patchy expression of VIP.

Discussion

Given the different actions of hormones that can be secreted by these composite tumors, we suggest that pheochromocytomas with diversified secretory capabilities may be an underrecognized clinical entity. Localized disease is often amenable to surgical resection, although management of metastatic disease is not well established due to the rarity of these tumors and lack of randomized trials.

Conclusion

In patients presenting with diarrhea of unclear etiology or the suggestion of secondary hypertension, assessment for a possible neuroendocrine tumor may be prudent. If an adrenal mass is discovered but the patient exhibits atypical symptoms of catecholamine excess, a diagnosis of composite pheochromocytoma with multisecretory properties should be considered.

Vasoactive intestinal peptide producing pheochromocytoma and intracardiac thrombosis

A case of pheochromocytoma producing vasoactive intestinal peptide (VIP) and left ventricular thrombus in the absence of cardiomyopathy or wall motion abnormalities on echocardiogram is presented along with a review of the relevant literature. A 30-year-old female of Afghani descent with past medical history of panic attacks presented with fever, cough, sore throat, vomiting, and was found to have an 11 cm adrenal mass consistent with primary adrenocortical adenoma versus carcinoma. Her tumor elicited catechols and vasoactive intestinal peptide. Her hospitalization was complicated by left ventricular thrombosis leading to an embolic injury to her right kidney, respiratory failure, need for transient dialysis and urinary tract infections. She developed a profuse secretory diarrhea and decision was made to treat with empiric octreotide infusion and imodium with improvement in symptoms. She underwent coil and particle embolization followed by resection. Followup PET gallium scan showed no evidence of residual disease or metastasis. VIP producing pheochromocytoma associated with intracardiac thrombosis is rare. Outcomes depend on prompt diagnosis of the pheochromocytoma and multidisciplinary approach to management.

Case Report: Irreversible Watery Diarrhea, Severe Metabolic Acidosis, Hypokalemia and Achloridria Syndrome Related to Vasoactive Intestinal Peptide Secreting Malignant Pheochromocytoma

BACKGROUND

Pheochromocytoma (PHEO) clinical manifestations generally mirror excessive catecholamines secretion; rarely the clinical picture may reflect secretion of other hormones. Watery diarrhea, hypokalemia and achlorhydria (WDHA) is a rare syndrome related to excessive secretion of vasoactive intestinal peptide (VIP).

CLINICAL CASE

A 73-year-old hypotensive man affected by adrenal PHEO presented with weight loss and watery diarrhea associated with hypokalemia, hyperchloremic metabolic acidosis (anion gap 15 mmol/l) and a negative urinary anion gap. Abdominal computed tomography scan showed a right adrenal PHEO, 8.1 cm in maximum diameter, with tracer uptake on ⁶⁸GaDOTA-octreotate positron emission tomography. Metastasis in lumbar region and lung were present. Both chromogranin A and VIP levels were high (more than10 times the normal value) with slightly elevated urine normetanephrine and metanephrine excretion. Right adrenalectomy was performed and a somatostatin analogue therapy with lanreotide started. Immunostaining showed chromogranin A and VIP co-expression, with weak somatostatin-receptor-2A positivity. In two months, patient clinical conditions deteriorated with severe WDHA and multiple liver and lung metastasis. Metabolic acidosis and hypokalemia worsened, leading to hemodynamic shock and exitus.

CONCLUSIONS

A rare case of WDHA syndrome caused by malignant VIP-secreting PHEO was diagnosed. High levels of circulating VIP were responsible of the rapidly evolving clinical picture with massive dehydration and weight loss along with severe hyperchloremic metabolic acidosis and hypokalemia due to the profuse untreatable diarrhea. The rescue treatment with lanreotide was unsuccessful because of the paucity of somatostatin-receptor-2A on VIP-secreting PHEO chromaffin cells.

Intricacies of the Molecular Machinery of Catecholamine Biosynthesis and Secretion by Chromaffin Cells of the Normal Adrenal Medulla and in Pheochromocytoma and Paraganglioma

The adrenal medulla is composed predominantly of chromaffin cells producing and secreting the catecholamines dopamine, norepinephrine, and epinephrine. Catecholamine biosynthesis and secretion is a complex and tightly controlled physiologic process. The pathways involved have been extensively studied, and various elements of the underlying molecular machinery have been identified. In this review, we provide a detailed description of the route from stimulus to secretion of catecholamines by the normal adrenal chromaffin cell compared to chromaffin tumor cells in pheochromocytomas. Pheochromocytomas are adrenomedullary tumors that are characterized by uncontrolled synthesis and secretion of catecholamines. This uncontrolled secretion can be partly explained by perturbations of the molecular catecholamine secretory machinery in pheochromocytoma cells. Chromaffin cell tumors also include sympathetic paragangliomas originating in sympathetic ganglia. Pheochromocytomas and paragangliomas are usually locally confined tumors, but about 15% do metastasize to distant locations. Histopathological examination currently poorly predicts future biologic behavior, thus long term postoperative follow-up is required. Therefore, there is an unmet need for prognostic biomarkers. Clearer understanding of the cellular mechanisms involved in the secretory characteristics of pheochromocytomas and sympathetic paragangliomas may offer one approach for the discovery of novel prognostic biomarkers for improved therapeutic targeting and monitoring of treatment or disease progression.

An Institutional Experience of Tumor Progression to Pituitary Carcinoma in a 15-Year Cohort of 1055 Consecutive Pituitary Neuroendocrine Tumors

Pituitary carcinoma is a rare disease, defined by the presence of cerebrospinal or distant metastasis of a pituitary neuroendocrine tumor (PitNET). To review our institutional experience of pituitary carcinoma, we searched the database of the UHN Endocrine Oncology Site group and the University Health Network pathology laboratory information system from 2001 to 2016. Among 1055 PitNETs from 1169 transsphenoidal resections, we identified 4 cases of pituitary carcinoma, indicating that pituitary carcinoma represents around 0.4% of PitNETs. All four patients were women. The age at initial presentation ranged from 23 to 54 years. Two patients had Cushing disease with corticotroph tumors; one was initially a densely granulated corticotroph tumor that evolved to become sparsely granulated, while the other was a Crooke cell tumor. One patient had a functioning sparsely granulated lactotroph tumor and one had a clinically silent poorly differentiated PIT1 lineage tumor. Apart from a relatively high Ki67 labeling index (≥ 10%) in three tumors, there were no cytomorphologic features at the time of initial presentation that could predict subsequent metastatic behavior. The time from diagnosis of the pituitary neuroendocrine tumor to the diagnosis of malignancy was 3 to 14 years. Therapies included somatostatin analogs, external beam radiotherapy, chemotherapies including capecitabine/temozolomide, everolimus, sunitinib, bevacizumab, and peptide receptor radionuclide therapy (PRRT). One patient died of disease 18 years after initial diagnosis, underscoring the protracted course of this ultimately fatal neuroendocrine malignancy.

Octreotide reverses shock due to vasoactive intestinal peptide-secreting adrenal pheochromocytoma: A case report and review of literature

Vasoactive intestinal peptide-producing tumors (VIPoma) usually originate in the pancreas and are characterized by diarrhea, hypokalemia, and achlorhydria (WDHA syndrome). In adults, nonpancreatic VIPoma is very rare. Herein, we report an unusual case of VIP-producing pheochromocytoma marked by persistent shock, flushing, and watery diarrhea and high sensitivity to octreotide. A 53-year-old woman was hospitalized for sudden-onset hypertension with convulsions, which then rapidly evolved to persistent shock, flushing, and watery diarrhea. Abdominal computed tomography indicated a left adrenal mass, accompanied by bleeding; and marked elevations of both plasma catecholamine and VIP concentrations were documented via laboratory testing. Surprisingly, all clinical symptoms responded swiftly to octreotide treatment. Once surgically treated, hormonal levels normalized in this patient, and the clinical symptoms dissipated. Postoperative pathological and immunohistopathological studies confirmed a VIP-secreting pheochromocytoma with strong, diffuse positivity for somatostatin receptor type 2. During a 6-mo follow-up period, she seemed in good health and was symptom-free.

Sunitinib in the therapy of malignant paragangliomas: report on the efficacy in a SDHB mutation carrier and review of the literature

Metastatic pheochromocytomas (PHEOs) and paragangliomas (sPGLs) are rare neural crest-derived tumors with a poor prognosis. About 50% of them are due to germ-line mutations of the SDHB gene. At present, there is no cure for these tumors. Their therapy is palliative and represented by different options among which antiangiogenic drugs, like sunitinib, have been hypothesized to be effective especially in malignant SDHB mutated tumors. We report the effects of sunitinib therapy in a SDHB mutation carrier affected by a malignant sPGL. During 101 weeks of therapy at different doses, sunitinib was able to cause a partial response and then a stable disease for a total of 78 weeks. This favorable response is the longest, out of the 35 so far reported in the literature, registered in a patient treated exclusively with sunitinib but, similarly to the other responses, the effect was limited in time. From our analysis of the scanty data present in the literature, the effect of sunitinib does not seem to be different among wild-type patients and those carrying a cluster 1 germ-line mutation. Sunitinib seems able to slow the disease progression in some patients with malignant PHEO/PGL and therefore may represent a therapeutic option, although randomized controlled studies are needed to assess its efficacy definitively in the treatment of these aggressive tumors.