Surgery for Pheochromocytoma: A Single-Center Review of 60 Cases from South Africa

Predictive Factors for Conversion from Laparoscopic Adrenalectomy to Open Surgery: A 9-Year Review of 911 Cases

Background: With the development of minimally invasive techniques, laparoscopic adrenalectomy (LA) has become the standard for the treatment of adrenal surgical diseases, but conversion to open adrenalectomy (OA) is also necessary in some cases. The purpose of this study was to investigate the risk factors for conversion from LA to OA. Methods: A retrospective study was performed on 911 patients who were diagnosed with adrenal tumors and underwent LA in the Department of Urology, Second Hospital of Lanzhou University from January 2013 to December 2021. According to the surgical methods, the patients were divided into the laparoscopic group (n = 873) and the conversion group (n = 38). Logistic regression was used to analyze the independent risk factors of conversion, and the logistic regression equation was established to predict the probability of conversion. Results: In this study, 38 patients (4.17%) were converted to open. In the univariate analysis, body mass index (P = .037), tumor side (P < .001), tumor size (P < .001), surgical approach (P < .001), and histological type (P = .006) were significantly associated with conversion. In the multivariate analysis, tumor diameter >7 cm (odds ratio = 2.835, 95% confidence interval 1.096-7.335; P = .032), transabdominal approach (odds ratio = 2.400, 95% confidence interval 1.136-5.074; P = .022), pheochromocytoma (odds ratio = 5.018, 95% confidence interval 1.964-12.822; P = .001), and malignant tumor (odds ratio = 17.781, 95% confidence interval 4.156-76.075; P < .001) were independent risk factors for transition opening. The logistic regression equation showed good power to predict conversion. Conclusion: Tumor size, surgical approach, and histological type were predictive factors for conversion from a laparoscopic to an open procedure. Preoperative evaluation of these characteristics is of great value for clinicians to evaluate the risk of conversion and make a surgical plan. It can not only reduce the conversion rate but also help to improve the intraoperative situation and shorten the length of hospital stays.

A Study of Paraganglioma Cases With Non-European Ancestry

Capable of generating excess catecholamines, untreated extra-adrenal paragangliomas (PGLs) result in severe cardiovascular morbidity and mortality. Increasingly, a hereditary basis can be identified to underlie PGLs, though such data are largely absent in populations of non-European descent. We present two patients with PGL, both exhibiting similar age, sex, and geographic ancestry. Our patients are unrelated, Kinyarwanda-speaking females from the Democratic Republic of the Congo. The first patient presented with lower extremity edema and poorly controlled hypertension and was found to have multifocal PGL in the abdomen and bladder, proven by biopsy and treated with surgical excision. Our second patient presented with palpitations, shortness of breath, headache, and hypertension, was found to have mediastinal PGL, and underwent surgical excision. Genetic testing was negative in both cases. The first patient has not shown recurrence based on active surveillance with imaging and biochemical testing. There is a concern for recurrence in the second patient, eight years after diagnosis, which is currently being investigated. Our second patient lived at a high altitude for most of her life, pointing toward a possible role of hypoxia in the pathogenesis of her tumor development. Our cases raise questions that require active inquiry regarding additional environmental and/or genetic factors that might predispose to PGLs in uncommon anatomic sites and in understudied, vulnerable populations.

Dutch founder SDHB exon 3 deletion in patients with pheochromocytoma-paraganglioma in South Africa

OBJECTIVE

Screening studies have established genetic risk profiles for diseases such as multiple endocrine neoplasia type 1 (MEN1) and pheochromocytoma-paraganglioma (PPGL). Founder effects play an important role in the regional/national epidemiology of endocrine cancers, particularly PPGL. Founder effects in the Netherlands have been described for various diseases, some of which established themselves in South Africa due to Dutch emigration. The role of Dutch founder effects in South Africa has not been explored in PPGL.

DESIGN

We performed a single-center study in South Africa of the germline genetic causes of isolated/syndromic neuroendocrine tumors.

METHODS

Next-generation panel, Sanger sequencing and multiplex ligand-dependent probe amplification for endocrine neoplasia risk genes.

RESULTS

From a group of 13 patients, we identified 6 with PPGL, 4 with sporadic or familial isolated pituitary adenomas, and 3 with clinical MEN1; genetic variants were identified in 9/13 cases. We identified the Dutch founder exon 3 deletion in SDHB in two apparently unrelated individuals with distinct ethnic backgrounds that had metastatic PPGL. Asymptomatic carriers with this Dutch founder SDHBexon 3 deletion were also identified. Other PPGL patients had variants in SDHB, and SDHD and three MEN1variants were identified among MEN1 and young-onset pituitary adenoma patients.

CONCLUSIONS

This is the first identification of a Dutch founder effect for PPGL in South Africa. Awareness of the presence of this exon 3 SDHB deletion could promote targeted screening at a local level. Insights into PPGL genetics in South Africa could be achieved by studying existing patient databases for Dutch founder mutations in SDHx genes.

SDHB-Associated Paraganglioma Syndrome in Africa-A Need for Greater Genetic Testing

A germline mutation is identified in almost 40% of pheochromocytoma/paraganglioma (PPGL) syndromes. Genetic testing and counseling are essential for the management of index cases as well as presymptomatic identification and preemptive management of affected family members. Mutations in the genes encoding the mitochondrial enzyme succinate dehydrogenase (SDH) are well described in patients with hereditary PPGL. Among patients of African ancestry, the prevalence, phenotype, germline mutation spectrum, and penetrance of SDH mutations is poorly characterized. We describe a multifocal paraganglioma in a young African male with an underlying missense succinate dehydrogenase subunit B (SDHB) mutation and a history of 3 first-degree relatives who died at young ages from suspected cardiovascular causes. The same SDHB mutation, Class V variant c.724C>A p.(Arg242Ser), was detected in one of his asymptomatic siblings. As there are limited data describing hereditary PPGL syndromes in Africa, this report of an SDHB-associated PPGL is a notable contribution to the literature in this growing field. Due to the noteworthy clinical implications of PPGL mutations, this work highlights the existing need for broader genetic screening among African patients with PPGL despite the limited healthcare resources available in this region.