Case report: patient with multiple paragangliomas treated with long acting somatostatin analogue

Metastatic Pheochromocytoma and Paraganglioma: Somatostatin Receptor 2 Expression, Genetics, and Therapeutic Responses

CONTEXT

Pheochromocytomas and paragangliomas (PPGLs) with pathogenic mutations in the succinate dehydrogenase subunit B (SDHB) are associated with a high metastatic risk. Somatostatin receptor 2 (SSTR2)-dependent imaging is the most sensitive imaging modality for SDHB-related PPGLs, suggesting that SSTR2 expression is a significant cell surface therapeutic biomarker of such tumors.

OBJECTIVE

Exploration of the relationship between SSTR2 immunoreactivity and SDHB immunoreactivity, mutational status, and clinical behavior of PPGLs. Evaluation of SSTR-based therapies in metastatic PPGLs.

METHODS

Retrospective analysis of a multicenter cohort of PPGLs at 6 specialized Endocrine Tumor Centers in Germany, The Netherlands, and Switzerland. Patients with PPGLs participating in the ENSAT registry were included. Clinical data were extracted from medical records, and immunohistochemistry (IHC) for SDHB and SSTR2 was performed in patients with available tumor tissue. Immunoreactivity of SSTR2 was investigated using Volante scores. The main outcome measure was the association of SSTR2 IHC positivity with genetic and clinical-pathological features of PPGLs.

RESULTS

Of 202 patients with PPGLs, 50% were SSTR2 positive. SSTR2 positivity was significantly associated with SDHB- and SDHx-related PPGLs, with the strongest SSTR2 staining intensity in SDHB-related PPGLs (P = .01). Moreover, SSTR2 expression was significantly associated with metastatic disease independent of SDHB/SDHx mutation status (P < .001). In metastatic PPGLs, the disease control rate with first-line SSTR-based radionuclide therapy was 67% (n = 22, n = 11 SDHx), and with first-line "cold" somatostatin analogs 100% (n = 6, n = 3 SDHx).

CONCLUSION

SSTR2 expression was independently associated with SDHB/SDHx mutations and metastatic disease. We confirm a high disease control rate of somatostatin receptor-based therapies in metastatic PPGLs.

Case Report: Octreotide plus CVD chemotherapy for the treatment of multiple metastatic paragangliomas after double resection for functional bladder paraganglioma and urothelial papilloma

Background

Metastatic pheochromocytomas and paragangliomas are rare neuroendocrine tumors with a poor prognosis. Bladder paraganglioma concomitant with urothelial papilloma is even rarer. However, the rate of tumor response to cyclophosphamide-vincristine-dacarbazine (CVD) chemotherapy and 5-year overall survival for patients with metastatic PPGLs remained lower. We described, for the first time, a case of a patient with multiple metastatic bladder PGL who received octreotide LAR combined with CVD chemotherapy after urological surgery and then octreotide therapy was continued during follow-up.

Case presentation

A 43-year-old male patient was admitted to the urology department for frequent micturition syncope concomitant with malignant hypertension. Preoperative findings were elevated levels of normetanephrine in 24-h urine or plasma. CT and MRI indicated diagnosis of suspicious bladder paraganglioma. Transurethral resection of bladder tumor combined with laparoscopic partial cystectomy was performed successfully after preoperative phenoxybenzamine with aggressive volume repletion for 7 days. The result of postoperative pathology was immediate-risk functional bladder paraganglioma (T2N0M0, Stage II) concomitant with urothelial papilloma, and the immunohistochemistry results of PPGL were positive for Ki-67 (15%), SDHB, CgA, and SSTR2. The patient achieved enhanced recovery with normal urination and no syncope after surgery. However, the results of ¹⁸F-FDG and ¹⁸F-DOTATATE PET/CT found that the metastatic localizations of bladder PGLs were in the liver, lung, and bones at the 8th month after surgery. The patient received octreotide long-acting repeatable plus six courses of CVD chemotherapy for 6 months, and then octreotide therapy was continued every 3 months until now. Metastatic localizations were stable in CT scans, and vanillylmandelic acid in 24-h urine was maintained at lower levels during follow-up.

Conclusion

Octreotide long-acting repeatable plus CVD chemotherapy after surgery could achieve stable disease in the case with multiple metastatic bladder PGLs, and the following octreotide therapy could maintain a state of stable disease during the period of 6-month follow-up.

Targeted Therapies in Pheochromocytoma and Paraganglioma

Molecular targeted therapy plays an increasingly important role in the treatment of metastatic pheochromocytomas and paragangliomas (PPGLs), which are rare tumors but remain difficult to treat. This mini-review provides an overview of established molecular targeted therapies in present use, and perspectives on those currently under development and evaluation in clinical trials. Recently published research articles, guidelines, and expert views on molecular targeted therapies in PPGLs are systematically reviewed and summarized. Some tyrosine kinase inhibitors (sunitinib, cabozantinib) are already in clinical use with some promising results, but without formal approval for the treatment of PPGLs. Sunitinib is the only therapeutic option which has been investigated in a randomized placebo-controlled clinical trial. It is clinically used as a first-, second-, or third-line therapeutic option for the treatment of progressive metastatic PPGLs. Some other promising molecular targeted therapies (hypoxia-inducible factor 2 alpha [HIF2α] inhibitors, tumor vaccination together with checkpoint inhibitors, antiangiogenic therapies, kinase signaling inhibitors) are under evaluation in clinical trials. The HIF2α inhibitor belzutifan may prove to be particularly interesting for cluster 1B-/VHL/EPAS1-related PPGLs, whereas antiangiogenic therapies seem to be primarily effective in cluster 1A-/SDHx-related PPGLs. Some combination therapies currently being evaluated in clinical trials, such as temozolomide/olaparib, temozolomide/talazoparib, or cabozantinib/atezolizumab, will provide data for novel therapy for metastatic PPGLs. It is likely that advances in such molecular targeted therapies will play an essential role in the future treatment of these tumors, with more personalized therapy options paving the way towards improved therapeutic outcomes.

Pancreatic paraganglioma diagnosed by endoscopic ultrasound-guided fine needle aspiration: A case report and review of literature

BACKGROUND

Pancreatic paragangliomas (PPGL) are rare benign neuroendocrine neoplasms but malignancy can occur. PPGL are often misdiagnosed as pancreatic neuroendocrine tumor or pancreatic adenocarcinoma.

CASE SUMMARY

We reviewed 47 case reports of PPGL published in PubMed to date. Fifteen patients (15/47) with PPGL underwent endoscopic ultrasound-guided fine needle aspiration (EUS-FNA). Only six (6/15) were correctly diagnosed as PPGL. All patients with PPGL underwent surgical resection except three (one patient surgery was aborted because of hypertensive crisis, two patients had metastasis or involvement of major vessels). Our patient remained on close surveillance as she was asymptomatic.

CONCLUSION

Accurate preoperative diagnosis of PPGL can be safely achieved by EUS-FNA with immunohistochemistry. Multidisciplinary team approach should be considered to bring the optimal results in the management of PPGL.

Somatostatin Receptors and Analogs in Pheochromocytoma and Paraganglioma: Old Players in a New Precision Medicine World

Neuroendocrine tumors overexpress somatostatin receptors, which serve as important and unique therapeutic targets for well-differentiated advanced disease. This overexpression is a well-established finding in gastroenteropancreatic neuroendocrine tumors which has guided new medical therapies in the administration of somatostatin analogs, both "cold", particularly octreotide and lanreotide, and "hot" analogs, chelated to radiolabeled isotopes. The binding of these analogs to somatostatin receptors effectively suppresses excess hormone secretion and tumor cell proliferation, leading to stabilization, and in some cases, tumor shrinkage. Radioisotope-labeled somatostatin analogs are utilized for both tumor localization and peptide radionuclide therapy, with ⁶⁸Ga-DOTATATE and ¹⁷⁷Lu-DOTATATE respectively. Benign and malignant pheochromocytomas and paragangliomas also overexpress somatostatin receptors, irrespective of embryological origin. The pattern of somatostatin receptor overexpression is more prominent in succinate dehydrogenase subunit B gene mutation, which is more aggressive than other subgroups of this disease. While the Food and Drug Administration has approved the use of ⁶⁸Ga-DOTATATE as a radiopharmaceutical for somatostatin receptor imaging, the use of its radiotherapeutic counterpart still needs approval beyond gastroenteropancreatic neuroendocrine tumors. Thus, patients with pheochromocytoma and paraganglioma, especially those with inoperable or metastatic diseases, depend on the clinical trials of somatostatin analogs. The review summarizes the advances in the utilization of somatostatin receptor for diagnostic and therapeutic approaches in the neuroendocrine tumor subset of pheochromocytoma and paraganglioma; we hope to provide a positive perspective in using these receptors as targets for treatment in this rare condition.

Role of 68Ga-DOTATATE PET/CT in a Case of SDHB-Related Pterygopalatine Fossa Paraganglioma Successfully Controlled with Octreotide

We describe an unusual case of a 42-year-old female with an unresectable succinate dehydrogenase subunit B (SDHB)-related pterygopalatine fossa paraganglioma. She underwent somatostatin receptor imaging with ⁶⁸Ga-DOTA(0)-Tyr(3)-octreotate (⁶⁸Ga-DOTATATE) positron emission tomography/computed tomography (PET/CT), which showed uptake in the above mentioned tumor. Hence, the patient was started on octreotide, a cold somatostatin analog, and responded with tumor stabilization and improvement of clinical symptoms for 36 months since initiation of octreotide therapy. This case demonstrates the role of ⁶⁸Ga-DOTATATE PET/CT in diagnostic localization and its subsequent role in treatment using cold somatostatin analog as a potential choice of therapy in the management of paraganglioma in an unusual location with limited therapeutic options.

Evaluation of somatostatin, CXCR4 chemokine and endothelin A receptor expression in a large set of paragangliomas

Paragangliomas are predominantly benign tumors, but in some cases invasive growth and also metastasis are observed. Given the limited number of nonsurgical treatment options, novel target structures for diagnostics and therapy of this tumor entity are urgently needed. In the present study, expression of all five somatostatin receptor (SST) subtypes, chemokine receptor CXCR4 and endothelin receptor type A (ETA) was assessed by means of immunohistochemistry in a total of 66 paraffin-embedded paraganglioma samples from 55 patients. The stainings were rated by means of the Immunoreactive Score and correlated to clinical data and to succinate dehydrogenase subunit B (SDHB) expression. SST2A was by far the most prominent receptor in the paragangliomas investigated. It was present in 89% of the tumors at a high intensity, followed by SST5, SST3, SST1 and SST4, which were detected in 47%, 35%, 35% and 13% of the samples, respectively. SDHB positive tumors exhibited significantly higher SST2A and SST3 expression as compared to SDHB negative cases. There was no correlation between SST and Ki-67 expression or grading of the tumors and no difference in SST expression between primary tumors and metastases. Cell surface expression of CXCR4 and ETA was detected only in few samples. On tumor capillaries, however, exceptionally strong staining for these two receptors was noticed in the vast majority of the tumors. In conclusion, paragangliomas are well suited for SST2A-based diagnostics and treatment modalities. An indirect targeting of these highly vascularized tumors via CXCR4 or ETA may also represent a promising future strategy.

Functional extra-adrenal paraganglioma of the retroperitoneum giving thoracolumbar spine metastases after a five-year disease-free follow-up: a rare malignant condition with challenging management

Paragangliomas are benign neoplasms that arise from the autonomic nervous system and the associated paraganglia. Although benign, they have been shown to possess metastatic potential. Extra-adrenal retroperitoneal paraganglioma with vertebral metastasis is considered very uncommon. Here, we present a case of a functional extra-adrenal paraganglioma of the retroperitoneum giving metastasis to T4 vertebra after five years of follow-up in a 48-year-old man who had been initially treated with complete resection of the primary tumor. The condition of the patient improved significantly after radiosurgery and somatostatin analogs treatment, until lumbar spine lesions appeared six months later. Our case demonstrates that retroperitoneal paraganglioma is a rare condition which should be considered in the differential diagnosis of a retroperitoneal mass combined with vertebral lesions. Additionally, increased physician awareness and long-term follow-up is mandatory for all patients with history of retroperitoneal paraganglioma since metastases may occur after long latent intervals from the initial diagnosis.

Clinical characteristics and surgical treatment of spinal paraganglioma: A case series of 18 patients

BACKGROUND AND OBJECTIVES

Paraganglioma rarely develops in the spine. With few cases reported, little knowledge about this disease was known. The objective of this study is to illustrate the clinical features, imaging manifestations, pathological appearances and long-term outcomes of the consecutive surgeries by literature review.

METHODS

The clinical and follow-up data of 18 patients who were diagnosed of spinal paraganglioma and treated with surgeries in our hospitals from 2003 to 2014 were retrospectively analyzed.

RESULT

A total of fourteen patients radiographed of intra-spinal tumor underwent extra-capsular tumor resection. Of five patients with obvious vertebral bone damage, four cases underwent piecemeal resection, and the left one with sacral tumor underwent en bloc tumor excision. Spinal reconstruction was performed in all cases. Follow-up lasted for 16-96 months (44.1 months on average). There was no local recurrence or distant metastasis in cases without obvious bone invasion. Of those five cases with vertebral bone damage, one case suffered and survived from the repeat relapse of T1 vertebral body tumor. Local recurrence was not observed in one case with T10 vertebral tumor after tumor resection, but the tumor metastasized to T2 attachment during the follow-up and was finally eradicated by re-operation. No tumor recurrence was observed in the left three cases.

CONCLUSION

Paraganglioma, usually benign, rarely occurs. Surgical resection, especially complete surgical resection, is preferred to treat spinal paraganglioma. Chemotherapy, radiotherapy, use of octreotide and other somatostatin are selected as adjuvant therapies, but their effects remain unknown.

Non-functional paraganglioma of retroperitoneum mimicking pancreatic mass with concurrent urinary bladder paraganglioma: an extremely rare entity

Paragangliomas are extra-adrenal tumours of the autonomic nervous system, which rarely present as primary retroperitoneal mass mimicking pancreatic malignancy (incidence 2-8 per million populations). Urinary Bladder Paraganglioma are also extremely rare (0.06% of all Bladder Tumour and 6% of Paragangliomas) with most being malignant and high grade tumours. Non-functional varieties of both tumours are usually incidentally diagnosed. The possibility for malignant transformation in them makes surgical excision the treatment of choice. A 45-year-old lady with abdominal pain was investigated to have a complex retroperitoneal mass behind head of pancreas and a urinary bladder mass. Complete excision of retroperitoneal and bladder lesion was done. Histopathological examinations of both specimens were suggestive of Paraganglioma with no abnormal mitotic activity and capsular/vascular invasion. Although concurrent non functional paragangliomas had been reported but the synchronous non-functional paragangliomas of retroperitoneum and urinary bladder reported in this case is extremely rare and is not reported so far in English literature.

Metastatic paraganglioma of the spine: case report and review of the literature

Paragangliomas are relatively rare tumors, accounting for only about 0.3% of all neoplasms. Most paragangliomas are defined as benign in nature, but 10-20% possess metastatic potential. There have been scattered reports of metastatic paraganglioma in the literature, but in rare circumstances, paragangliomas can metastasize to the spinal column causing destruction or compression of the spinal cord, clinically manifesting as pain or neurological deficit. We report a case of metastatic paraganglioma in which a 47-year-old man had spinal metastasis from a primary abdominal paraganglioma and was found to be positive for SDHB mutation, portraying negative implications for prognosis. Long-term follow-up is reported. In addition, we review the literature on the topic of metastatic paraganglioma, management of paragangliomas involving spine, and touch on the importance of the presence of SDHB mutations in these cases.

Primary retroperitoneal paraganglioma simulating a pancreatic mass: a case report and review of the literature

Paragangliomas are extra-adrenal tumors of the autonomic nervous system and may be found within the skull base, neck, chest, and abdomen. When presenting within the abdominal cavity, they may arise as a primary retroperitoneal neoplasm and can mimic vascular malformations or other conditions related to specific retroperitoneal organs such as the pancreas, kidneys, or adrenals. Retroperitoneal paragangliomas are mostly benign with good prognosis; however, they can present with abdominal pain, palpable mass, or hypertensive episodes. Patients should be initially evaluated with catecholamine levels, followed by computed tomography or magnetic resonance imaging to locate the primary lesion. Surgical excision remains the mainstay of treatment, although advanced disease and proximity to vital organs can make excision difficult or impossible. This case report describes a patient who initially underwent work up for a suspected pancreatic head mass which was discovered to be a retroperitoneal paraganglioma by frozen section.