Evaluation of quantitative parameters for distinguishing pheochromocytoma from other adrenal tumors

A Case of Pheochromocytoma With Coagulation Necrosis Due to Hypertensive Crisis Aggravated by Contrast-Enhanced CT Scan and Negative 123I-Metaiodobenzylguanidine (MIBG) Scintigraphy

123I-metaiodobenzylguanidine (123I-MIBG) scintigraphy is a highly sensitive and specific imaging test for the diagnosis of pheochromocytoma. Typical pheochromocytomas are positive on 123I-MIBG scintigraphy; however, cases of paragangliomas eliciting negative results have been reported. We encountered a case of hypertensive crisis resulting in extensive coagulative necrosis of a pheochromocytoma and negative findings on 123I-MIBG scintigraphy. A 50-year-old Japanese female presented with an acute onset of vomiting, epigastralgia, and abdominal pain. Immediately after contrast-enhanced CT, the patient developed respiratory failure and was intubated. The CT scan revealed a 5-cm left adrenal mass, and a pheochromocytoma crisis was suspected. The patient's condition stabilized following phentolamine administration. Regarding the assessment for pheochromocytoma, plasma metanephrine levels were not markedly increased, and 123I-MIBG scintigraphy was negative. However, a histological examination of the left adrenal mass revealed extensive coagulative necrosis of the entire adrenal mass, comprising trabecular and alveolar growth of large polygonal cells that were immunopositive for chromogranin A/synaptophysin, thereby suggesting a diagnosis of pheochromocytoma. There have been three reported cases of 123I-MIBG scintigraphy-negative pheochromocytomas because of pure avascular necrosis without hemorrhage or rupture. To the best of our knowledge, this is the first reported case of massive tumor necrosis due to hypertensive crisis exacerbated after contrast-enhanced CT imaging. In conclusion, pheochromocytoma cannot be ruled out even with negative findings on 123I-MIBG scintigraphy. Accordingly, clinical judgment must be made based on a comprehensive assessment of the clinical course and pathological diagnosis, especially for cases involving a hypertensive crisis.

Prevalence of Functioning Adrenal Incidentalomas: A Systematic Review and Meta-analysis

CONTEXT

Adrenal hyperfunction is associated with an increased risk of cardiometabolic complications in subjects with adrenal incidentaloma (AI). Reliable prevalence estimates of functioning AIs are important to direct resources allocations.

OBJECTIVE

To assess the prevalence of autonomous/possible autonomous cortisol secretion (ACS), primary aldosteronism (PA), pheochromocytoma (PHEO), and Cushing syndrome (CS) in patients with AI.

METHODS

We performed a comprehensive search of multiple databases (PubMed, Ovid MEDLINE, Web of Science) for potentially relevant studies without language restriction, up to February 2022. Of the 1661 publications evaluated at title and abstract levels, 161 were examined as full text and 36 were included. Study level clinical data were extracted by 3 independent reviewers.

RESULTS

The overall prevalence of functioning AIs was 27.5% (95% CI 23.0, 32.5). ACS/possible ACS, with a prevalence of 11.7% (95% CI 8.6, 15.7), was the most frequent hormonal alteration, while PA occurred in 4.4% of the patients (95% CI 3.1, 6.2). Subgroup analysis showed that PA was more prevalent in patients from Asia than in patients from Europe/America; in contrast, ACS/possible ACS had a lower prevalence in Asian countries. At meta-regression analysis, the prevalence of ACS/possible ACS was influenced by the proportion of female patients, while the prevalence of PA was positively associated with the proportion of patients with hypertension and the publication year. Finally, PHEO and CS prevalence were 3.8% (95% CI 2.8, 5.0) and 3.1% (95% CI 2.3, 4.3) respectively.

CONCLUSION

This meta-analysis provides extensive data on the prevalence of functioning AIs and the factors affecting heterogeneity in prevalence estimates.

Recent advances in the management of pheochromocytoma and paraganglioma

Pheochromocytomas and paragangliomas (PPGLs) are rare tumors that cause refractory hypertension and hypertensive crisis. Although metastatic disease accounts for 30% of PPGLs, the diagnosis of malignancy is difficult without the presence of metastatic lesions. Here, we review several advancements in the diagnosis and treatment of PPGL. A nationwide epidemiological survey in Japan revealed that the annual number of patients with PPGL was 3000, which was higher than that reported previously. While plasma and urine fractionated metanephrines are recommended for use in specific biochemical testing for diagnosis, creatinine-corrected fractionated metanephrines in spot urine samples that had been widely used in Japan as a convenient screening test were shown to be as useful as 24-h urine fractionated metanephrines. Regarding imaging studies, a more specific functional imaging for PPGLs, ⁶⁸Ga DOTATATE, was newly developed. ⁶⁸Ga DOTATATE provides a clear image with high sensitivity and specificity. Currently, PASS or GAPP histological scores and SDHB immunostaining are clinically used to attempt to discriminate benign from malignant tumors. However, since this distinguishing process remains difficult, all cases were classified as malignant with the possibility of metastasis in the WHO classification of endocrine tumors updated in 2017. Approximately 60% of PPGLs have germline mutations in PPGL-related genes. Currently, the genes are classified into two clusters based on their mechanism for the etiology of tumorigenesis. Based on the possible mechanisms of tumor development associated with gene mutations, several molecular target drugs are under evaluation to explore more promising treatments for malignant PPGL.

Not all adrenal incidentalomas require biochemical testing to exclude pheochromocytoma: Mayo clinic experience and a meta-analysis

Background

Excluding a pheochromocytoma is important when a patient presents with an incidentally discovered adrenal mass. However, biochemical testing for pheochromocytoma can be cumbersome, time consuming, or falsely positive. Our objective was to determine if unenhanced computed tomography (CT) imaging alone can be used to rule out pheochromocytoma.

Methods

We performed a retrospective study of all patients with a pathologically confirmed pheochromocytoma and unenhanced CT imaging who were treated at the Mayo Clinic between 1998 and 2016. Additionally, we performed a systematic review and meta-analysis of original studies published after 2005 with patients who had adrenal masses, more than 10 patients with pheochromocytomas, and reported attenuation on unenhanced CT imaging in Hounsfield units (HU).

Results

In the Mayo cohort, we identified 186 patients and 199 pheochromocytomas with unenhanced CT imaging. The mean unenhanced CT attenuation was 35±9 HU (range, 15-62), and only 15 tumors had attenuation ≤20 HU. The systematic review identified 26 studies (1,217 tumors), and 23 studies provided a mean unenhanced CT attenuation. The overall mean unenhanced CT attenuation across the studies was 35.6 HU (95% CI, 22.0-49.1 HU). A cutoff of >10 HU had a 100% sensitivity (95% CI, 1.00-1.00) for pheochromocytoma with low heterogeneity between the 21 qualified studies (I²=0%). Sensitivity for pheochromocytoma was 100% and 99% for an unenhanced CT attenuation cutoff of >15 and >20 HU.

Conclusions

Biochemical testing may not be required to exclude pheochromocytoma if an incidental adrenal mass has low attenuation (<10 HU) on unenhanced CT images.

Predictors of recurrence of pheochromocytoma and paraganglioma: a multicenter study in Piedmont, Italy

The available data on the natural history of pheochromocytomas and paragangliomas after radical surgery are heterogeneous and discordant. The aim of our retrospective multicenter study was to find predictors of recurrence in patients with pheochromocytomas and sympathetic paragangliomas submitted to radical surgery in Piedmont (a region in northwest Italy). We collected data from 242 patients diagnosed between 1990 and 2016. Forty-two patients (17.4%) had disease recurrence. Multivariate analysis showed that genetic mutation (HR = 3.62; 95% CI 1.44-9.13; p = 0.006), younger age (HR = 0.97; 95% CI 0.95-0.99; p = 0.031) and larger tumor size (HR = 1.01; 95% CI 1.00-1.02; p = 0.015) were independently associated with a higher recurrence risk of pheochromocytoma and paraganglioma; in pheochromocytomas, genetic mutation (HR = 3.4; 95% CI 1.00-11.48; p = 0.049), younger age (HR = 0.97; 95% CI 0.94-0.99; p = 0.02), higher tumor size (HR = 1.01; 95% CI 1.00-1.03; p = 0.043) and PASS value (HR = 1.16; 95% CI 1.03-1.3; p = 0.011) were associated with recurrence. Moreover, tumor size was the only predictor of metastatic pheochromocytoma and paraganglioma (HR = 4.6; 95% CI 1.4-15.0; p = 0.012); tumor size (HR = 3.93; 95% CI 1.2-16.4; p = 0.026) and PASS value (HR = 1.27; 95% CI 1.06-1.53; p = 0.007) were predictors of metastatic pheochromocytoma. In conclusion, our findings suggest that the recurrence of pheochromocytoma and sympathetic paraganglioma develops more frequently in younger subjects, patients with a family history of chromaffin tissue neoplasms, mutations in susceptibility genes, larger tumors and higher values of PASS. We recommend genetic testing in all patients with PPGL and strict follow-up at least on an annual basis.

Diagnostic Accuracy of Computed Tomography to Exclude Pheochromocytoma: A Systematic Review, Meta-analysis, and Cost Analysis

OBJECTIVES

To assess the diagnostic accuracy of unenhanced computed tomography (CT) attenuation values to exclude a pheochromocytoma in the diagnostic work-up of patients with an adrenal incidentaloma and to model the associated difference in diagnostic costs.

METHODS

The MEDLINE and Embase databases were searched from indexing to September 27, 2018, and studies reporting the proportion of pheochromocytomas on either side of the 10-Hounsfield unit (HU) threshold on unenhanced CT were included. The pooled proportion of pheochromocytomas with an attenuation value greater than 10 HU was determined, as were the modeled financial costs of the current and alternative diagnostic approaches.

RESULTS

Of 2957 studies identified, 31 were included (N=1167 pheochromocytomas). Overall risk of bias was low. Heterogeneity was not observed between studies (Q=11.5, P=.99, I²=0%). The pooled proportion of patients with attenuation values greater than 10 HU was 0.990 (95% CI, 0.984-0.995). The modeled financial costs using the new diagnostic approach were €55 (∼$63) lower per patient.

CONCLUSION

Pheochromocytomas can be reliably ruled out in the case of an adrenal lesion with an unenhanced CT attenuation value of 10 HU or less. Therefore, determination of metanephrine levels can be restricted to adrenal tumors with an unenhanced CT attenuation value greater than 10 HU. Implementing this novel diagnostic strategy is cost-saving.

Tumor characteristics and surgical outcome in incidentally discovered pheochromocytomas and paragangliomas

OBJECTIVE

The proportion of incidentally discovered pheochromocytomas and paragangliomas(PPGL) has increased over time. However, our knowledge of them is quite limited. The purpose of this retrospective study is to generalize the commonalities in incidentally discovered PPGL, offer evidences for clinical diagnosis and management.

METHODS

526 patients were included in our study after filtration from the database of West China Hospital of Sichuan University between May, 2007 and December, 2016.Among the patients, 148 of them were incidental findings and 378 of them were suspected findings. All patients' demography and tumor characteristics were recorded in detail, especially hemodynamic records and hormonal assays. The reasons for taking radiography were also collected. Most patients received preoperative medical preparation . Intraoperative and postoperative courses as well as surgical outcomes were also analyzed to identify differences between incidental findings and suspected findings.

RESULTS

Incidentally discovered PPGL took up 28.1% of the study population. Suspected PPGLs had a higher prevalence of hypertension, lower proportion of non-functioning PPGL, higher prevalence of MEN2 and better post-surgical blood pressure recovery than incidental finding group. However, patients in the incidental finding group showed no significant difference in preoperative blood pressure and hormonal assays with suspected findings in metaphrine and normetaphrine in plasma and urine (P>0.05).

CONCLUSIONS

Due to the development of technology, more PPGLs are discovered incidentally. Considering the tumor characteristics and surgical outcome, surgical decisions should be made more cautiously.