Adrenocortical carcinoma posing as a pheochromocytoma: a diagnostic dilemma

Management of Pheochromocytomas and Paragangliomas: A Case-Based Review of Clinical Aspects and Perspectives

Paraganglioma and pheochromocytoma are rare medical conditions. Thus, there are still a small number of studies, clinical trials, and evidence-based data in this field. This makes clinical decisions more difficult. In this study, we present a case report enriched with a short review of available essential clinical data, indicating the need for constant metoxycatecholamine level observation and a proper diagnostic imaging approach, especially in terms of ongoing pandemics. Our research also provides a summary of the molecular background of these diseases, indicating their future role in clinical management. We analyzed the ClinicalTrials.gov dataset in order to show future perspectives. In this paper, the use of the PET-CT before MRI or CT is proposed in specific cases during diagnosis processes contrary to the guidelines. PET-CT may be as effective as standard procedures and may provide a faster diagnosis, which is important in periods with more difficult access to health care, such as during the COVID-19 pandemic.

An Adrenocortical Carcinoma Associated with Non-Islet Cell Tumor Hypoglycemia and Aberrant ACTH Production

Introduction. Adrenocortical carcinomas (ACCs) are infrequently reported to present with severe hypoglycemia syndrome resulting from the secretion of insulin-like growth factor II (IGF-II) by tumor cells. Adrenocorticotropic hormone- (ACTH) independent hypercortisolism is the norm of hormonally active ACCs, but aberrant ACTH production by tumor cells can theoretically cause ACTH-dependent hypercortisolism. The purpose of this report was to present a case of an ACC manifested with the co-occurrence of two extremely rare presentations. Case Description. We present a rare case of a 43-year-old male patient admitted with recurrent episodes of severe non-ketotic and non-insulin-mediated hypoglycemia due to IGF-II mediated disease and ACTH-dependent Cushing's syndrome. He was diagnosed with a diffusely disseminated adrenocortical carcinoma with immunohistochemistry of tumor cells showing focal ACTH immunostain positivity. Conclusion. Non-islet cell tumor hypoglycemia and ACTH-dependent Cushing's syndrome are extremely rare presentations of an ACC, and co-occurrence of these entities in a single patient is never reported in the literature.

PREDICTIVE VALUE OF CHROMOGRANIN A IN A DIAGNOSIS TOWARDS PHEOCHROMOCYTOMA IN ADRENAL INCIDENTALOMA

Context

Some adrenal tumors, such as pheochromocytoma, can be life-threatening. Therefore it is crucial to distinguish them from other lesions, especially prior to surgery. Chromogranin A (CgA) seems to potentially be a good marker for tumors of chromaffin origin.

Objective

To assess the differentiating value of CgA in the diagnostic work-up of pheochromocytoma.

Design

Retrospective study of operated patients with adrenal incidentaloma with lesions > 10 Hounsfield's units (HU) on CT.

Subjects and methods

Thirty patients (11 males, 19 females; aged 61.5±21 years) were enrolled in the study. Patients using medications interfering with the assessment of CgA and metanephrines were excluded. Two groups were formed: those with pheochromocytoma (Ph, n=16) and those with non-pheochromocytoma (N-Ph, n=14) lesions. Data included radiological features of masses, serum CgA and 24-hour urine metanephrines (24 - HUM) concentrations.

Results

No difference in 24-HUM level nor tumor size or density was found between groups Ph and N-Ph. Median serum CgA concentration was higher in Ph group compared to the N-Ph: 99.35 (68.12-172.73) vs. 52.92 (34.37-101.26) ng/mL, respectively (P=0.04). In Ph group, the size of the lesion correlated negatively with density (r= -0.53, P=0.042). No significant correlation in CgA, 24-HUM, density or size of the lesion was found. Performed curve receiver operating characteristic (ROC) showed AUC=0.7232 for CgA. Taking into account CgA serum value of ≤ 50 ng/mL (sensitivity: 93.75%, specificity: 50.00%, P=0.012), we proposed an algorithm for management of lesions > 10 HU on CT.

Conclusion

CgA level ≤ 50 ng/mL might be useful in initial screening evidence for the exclusion of pheochromocytoma. It is crucial to eliminate factors interfering with the measurements.