Hereditary paragangliomas

Paraganglioma in a Young Adult Female Patient: A Case Report

Paragangliomas are catecholamine-secreting neuroendocrine tumors that originate from the chromaffin cells of the sympathetic ganglia. Roughly 10% of paragangliomas are malignant, resulting in a rare occurrence of 90-95 cases per 400 million people. Herein, we report a case of a 29-year-old female patient who presented with nausea, vomiting, and bloating and was found to have a large left retroperitoneal tumor upon imaging. The tumor was successfully removed, and subsequent histological analysis was compatible with the presence of a paraganglioma. This case serves as a reminder that despite its rarity, paragangliomas should never be dismissed as a differential diagnosis if correlating symptoms and diagnostic findings are consistent with that of paraganglioma etiology.

Bladder paraganglioma, gastrointestinal stromal tumor, and SDHB germline mutation in a patient with Carney-Stratakis syndrome: A case report and literature review

Background

Carney-Stratakis syndrome (CSS) is a rare dyad of paraganglioma (PGL)/pheochromocytoma (PHEO) and gastrointestinal stromal tumor (GIST). PGLs are neuroendocrine tumors of neural crest origin which are mostly found in the head, neck, and retroperitoneal space. GISTs are the most common mesenchymal tumors of the digestive tract, usually caused by KIT/PDGFRA mutations. Here, we reported a case of CSS with unusual bladder PGL and succinate dehydrogenase (SDH) deficient GIST due to a germline mutation in SDH-subunit B (SDHB) gene.

Case presentation

A 39-year-old female patient initially diagnosed with gastric GIST and isolated pelvic metastasis was eventually found to be CSS with bladder PGL and SDH-deficient GIST after surgery. This patient underwent resection of gastric and bladder tumors, and postoperative pathology confirmed the diagnosis of CSS. According to the next-generation sequencing (NGS), the patient carried a germline mutation in the SDHB gene, which was the cause of the disorder. The patient had no tumor recurrence with regular follow-up in 10 months.

Conclusions

CSS is an autosomal genetic disorder with no gender difference in incidence, and PGLs are more frequent than GISTs. SDH germline mutation is the molecular biological mechanism of CSS while the most common type is SDHB mutation. The unique mechanism of tumorigenesis including hypoxia and hypermethylation caused by SDH deficiency renders target therapy with tyrosine kinase inhibitors ineffective, therefore complete surgical resection is the optimal treatment in the absence of tumor metastases.

Retroperitoneal paraganglioma with loss of heterozygosity of the von Hippel-Lindau gene: a case report and review of the literature

Von Hippel-Lindau (VHL) disease is an autosomal dominant disease related to germline mutations in VHL. In VHL disease, pheochromocytoma develops in 10%-20% of patients because of germline mutations and loss of heterozygosity of VHL. However, the rate of paraganglioma associated with VHL is low compared with that of pheochromocytoma, and the reason is unknown. In this study, we performed germline and somatic mutation analyses of retroperitoneal paraganglioma that developed in a patient with clinically diagnosed VHL disease and investigated the tumorigenic mechanism of paraganglioma. The patient was a 25-year-old woman who was considered to have VHL disease on the basis of her family history. She was referred to our clinic to investigate a tumor at the bifurcation of the common iliac artery. The tumor was diagnosed as retroperitoneal paraganglioma by clinical evaluations. A left renal cell carcinoma was also suspected. Polymerase chain reaction direct sequencing analysis and polymorphic microsatellite analysis within the VHL locus suggested that loss of heterozygosity of VHL was associated with paraganglioma and renal cell carcinoma. Multiplex ligation-dependent probe amplification analysis showed a loss of the copy number of VHL exons in paraganglioma. These results suggest that VHL disease contributes to the development of paraganglioma. A literature review showed no reported common missense variants involved in the progression of paraganglioma. The loss of heterozygosity of VHL can be a tumorigenic mechanism of retroperitoneal paraganglioma in VHL disease. However, the low rate of paraganglioma compared with pheochromocytoma is not explained by their genetic background alone.

Carney Triad, Carney-Stratakis Syndrome, 3PAS and Other Tumors Due to SDH Deficiency

Succinate dehydrogenase (SDH) is a key respiratory enzyme that links Krebs cycle and electron transport chain and is comprised of four subunits SDHA, SDHB, SDHC and SDHD. All SDH-deficient tumors are caused by or secondary to loss of SDH activity. As many as half of the familial cases of paragangliomas (PGLs) and pheochromocytomas (PHEOs) are due to mutations of the SDHx subunits. Gastrointestinal stromal tumors (GISTs) associated with SDH deficiency are negative for KIT/PDGFRA mutations and present with distinctive clinical features such as early onset (usually childhood or adolescence) and almost exclusively gastric location. SDH-deficient GISTs may be part of distinct clinical syndromes, Carney-Stratakis syndrome (CSS) or dyad and Carney triad (CT). CSS is also known as the dyad of GIST and PGL; it affects both genders equally and is inherited in an autosomal dominant manner with incomplete penetrance. CT is a very rare disease; PGL, GIST and pulmonary chondromas constitute CT which shows female predilection and may be a mosaic disorder. Even though there is some overlap between CT and CSS, as both are due to SDH deficiency, CSS is caused by inactivating germline mutations in genes encoding for the SDH subunits, while CT is mostly caused by a specific pattern of methylation of the SDHC gene and may be due to germline mosaicism of the responsible genetic defect.

Orbital Paraganglioma and Succinate Dehydrogenase Staining for Genetic Testing Triage and Prognosis

PURPOSE OF THE STUDY

To describe the rare occurrence of a paraganglioma in the orbit and how to triage for genetic testing and assess the prognosis with succinate dehydrogenase subunit B (SDHB) immunohistochemical staining.

METHOD

Case report.

PROCEDURES

A 47-year-old 'healthy' male presented with painless exophthalmos and diplopia secondary to an infraorbital tumour mass.

RESULTS

The orbital biopsy was diagnosed as paraganglioma with positive staining with SDHB.

CONCLUSION

The rarity of an orbital paraganglioma was followed by the clinical search for a possible occult extraorbital primary paraganglioma. SDHB staining helped in the triage for genetic testing and gave an idea about the prognosis for this tumour.

15 YEARS OF PARAGANGLIOMA: The association of pituitary adenomas and phaeochromocytomas or paragangliomas

The combination of pituitary adenomas (PA) and phaeochromocytomas (phaeo) or paragangliomas (PGL) is a rare event. Although these endocrine tumours may occur together by coincidence, there is mounting evidence that, in at least some cases, classical phaeo/PGL-predisposing genes may also play a role in pituitary tumorigenesis. A new condition that we termed '3Pas' for the association of PA with phaeo and/or PGL was recently described in patients with succinate dehydrogenase mutations and PAs. It should also be noted that the classical tumour suppressor gene, MEN1 that is the archetype of the PA-predisposing genes, is also rarely associated with phaeos in both mice and humans with MEN1 defects. In this report, we review the data leading to the discovery of 3PAs, other associations linking PAs with phaeos and/or PGLs, and the corresponding clinical and molecular genetics.

Counseling patients with succinate dehydrogenase subunit defects: genetics, preventive guidelines, and dealing with uncertainty

The discovery that mutations in the succinate dehydrogenase (SDH) complex subunit (SDHA, B/C/D/AF2) genes predispose patients to the development of tumors has led to the identification of a large population of patients and relatives at risk for developing malignancies. The most frequent conditions associated with these mutations are the familial paraganglioma syndromes. Other tumors that are frequently associated with SDH mutations (SDHx) are gastrointestinal stromal tumors and renal cell carcinomas. A number of other rare associations have also been described. SDHx mutations are often clinically silent and metastatic, but they may also be aggressive in their presentation. The penetrance of these mutations is beginning to be understood, and the characteristics of the phenotype are being elucidated. However, the inability to accurately predict the appearance, nature, and location of tumors as well as their tendency to recur or metastasize pose challenges to those who counsel and manage patients with SDHx mutations. In this work, we present our approach for counseling these families in the context of the current uncertainties, while striving to maintain patient autonomy.

cAMP/PKA signaling defects in tumors: genetics and tissue-specific pluripotential cell-derived lesions in human and mouse

In the last few years, bench and clinical studies led to significant new insight into how cyclic adenosine monophosphate (cAMP) signaling, the molecular pathway that had been identified in the early 2000s as the one involved in most benign cortisol-producing adrenal hyperplasias, affects adrenocortical growth and development, as well as tumor formation. A major discovery was the identification of tissue-specific pluripotential cells (TSPCs) as the culprit behind tumor formation not only in the adrenal, but also in bone. Discoveries in animal studies complemented a number of clinical observations in patients. Gene identification continued in parallel with mouse and other studies on the cAMP signaling and other pathways.

Succinate dehydrogenase (SDHx) mutations in pituitary tumors: could this be a new role for mitochondrial complex II and/or Krebs cycle defects?

Succinate dehydrogenase (SDH) or mitochondrial complex II is a multimeric enzyme that is bound to the inner membrane of mitochondria and has a dual role as it serves both as a critical step of the tricarboxylic acid or Krebs cycle and as a member of the respiratory chain that transfers electrons directly to the ubiquinone pool. Mutations in SDH subunits have been implicated in the formation of familial paragangliomas (PGLs) and/or pheochromocytomas (PHEOs) and in Carney-Stratakis syndrome. More recently, SDH defects were associated with predisposition to a Cowden disease phenotype, renal, and thyroid cancer. We recently described a kindred with the coexistence of familial PGLs and an aggressive GH-secreting pituitary adenoma, harboring an SDHD mutation. The pituitary tumor showed loss of heterozygosity at the SDHD locus, indicating the possibility that SDHD's loss was causatively linked to the development of the neoplasm. In total, 29 cases of pituitary adenomas presenting in association with PHEOs and/or extra-adrenal PGLs have been reported in the literature since 1952. Although a number of other genetic defects are possible in these cases, we speculate that the association of PHEOs and/or PGLs with pituitary tumors is a new syndromic association and a novel phenotype for SDH defects.

Role of ultrasound and color Doppler imaging in the detection of carotid paragangliomas

INTRODUCTION

Carotid body paragangliomas (PGLs) are highly vascularized lesions that arise from the paraganglia located at the carotid bifurcation.

PURPOSE

To evaluate the usefulness of gray-scale ultrasound (US) and color Doppler ultrasound (CDUS) in the detection and follow-up of carotid PGLs of the neck.

MATERIALS AND METHODS

The authors retrospectively reviewed US and CDUS examinations of the neck performed in 40 patients with PGL syndrome type 1 and single or bilateral neck PGLs confirmed by CT or MRI; the patients had a total of 60 PGLs of the neck. US and CDUS outcome was compared to the outcome of second-line imaging techniques such as magnetic resonance imaging (MRI) or computed tomography (CT). The following findings were considered: presence/absence of focal lesions at US imaging and difference in maximum diameter of the lesion measured at US and MRI/CT. Results were compared using the Student's t-test.

RESULTS

Of the 60 PGLs of the neck only 5 (8.3%) were not visualized at US or CDUS examination. The difference in maximum diameter of these lesions measured at CT/MRI and US/CDUS ranged between -5 mm and +16 mm (mean difference 2.2 ± 6.0). This difference was statistically significant (p = 0.008).

CONCLUSIONS

US and CDUS are useful methods for identifying carotid PGLs also measuring less than 10 mm in diameter. However, diagnostic accuracy of US and CDUS is reduced in the measurement of the exact dimensions of the lesions.