Malignant paraganglioma arising from the kidney

Differential diagnosis and unusual diffuse cytokeratin expression in renal paraganglioma: A case report

Paraganglioma is a rare neuroendocrine tumor arising from undifferentiated cells of the primitive neural crest. We report a case of renal paraganglioma in a 67-year-old patient. Computed tomography demonstrated a solid mass in the middle and lower pole of the right kidney. Sonography revealed an enlarged right kidney with an irregular shape but distinct border. Renal cell carcinoma was diagnosed provisionally; the tumor was completely resected and submitted for pathological examination. Unexpectedly, histopathology and immunohistochemistry confirmed paraganglioma arising from the renal parenchyma. In this study, we report the exceptional occurrence of Paired box gene 8 (PAX-8) expression in a renal paraganglioma. In addition, we demonstrated diffuse cytokeratin positivity in this renal paraganglioma. Although our report of a paraganglioma originating from the kidney is not unique, our finding expands the known immunophenotypic spectrum of this tumor. The awareness of the possible occurrence of cytokeratin diffuse positivity in paraganglioma is relevant to avoiding misdiagnosis of paraganglioma.

Malignant Intrarenal/Renal Pelvis Paraganglioma with Co-Occurring SDHB and ATRX Mutations

Paragangliomas are rare neuroendocrine tumors which originate from embryonic neural crest cells. These tumors may arise from parasympathetic or sympathetic paraganglia, may secrete catecholamines, and can occur in varied anatomic locations, with some locations being less common than others. Hereditary paraganglioma-pheochromocytoma (PGL/PCC) syndromes are characterized by paragangliomas and pheochromocytomas and have been associated with germline heterozygous mutations in MAX, SDHA, SDHAF2, SDHB, SDHC, SDHD, or TMEM127. Herein, we report a case of a middle-aged male who was diagnosed with an intrarenal/renal pelvis paraganglioma after presenting in hypertensive crisis with palpitations, headache, and diaphoresis. He was later found to have extensive metastatic disease, as well as genetic testing that showed biallelic inactivation of SDHB and a co-occurring somatic ATRX mutation. Respectively, these germline and somatic mutations have been associated with increased risk of metastatic spread and clinical aggressiveness. Despite multiple surgical resections and various treatment modalities, the patient eventually elected for palliative care measures and died of disease. Together, the findings seen in this patient are unique and serve as an appropriate catalyst for discussing the unusual locations, interesting genetic profiles, and metastatic risk factors that may be associated with paragangliomas.

A primary malignant melanoma of the mediastinum with gross surgical view

Primary malignant mediastinal melanomas are rare. Few studies have reported on the chest computed tomography (CT) scan and histopathological features. We report a case of a primary malignant mediastinal melanoma in a 32-year-old man and provide a gross surgical view of the tumour.

Renal paraganglioma: report of a case managed by robotic assisted laparoscopic partial nephrectomy and review of the literature

We describe the pathological and clinical presentation of a rare case of renal paraganglioma occurring as an incidental left renal mass in a 58-year-old woman. The patient underwent robotic assisted laparoscopic partial nephrectomy, which is the first one in the literature.

Pigmented paraganglioma of the kidney: a case report

Paragangliomas are rare neoplasms arising from undifferentiated cells of the primitive neural crest. We report a case of a 57-year-old patient with renal pigmented paraganglioma that was an incidental finding. Histopathological examination showed typical morphology of paraganglioma, as well as the unusual feature of large amounts of pigment in the cytoplasm of the tumor cells which was confirmed by bleached Fontana-Masson. Electron microscopy showed abundant, pleomorphic electron-dense granules consistent with neuromelanin. The tumor cells were positive for CD56 and chromogranin A, negative for HMB-45. The unique morphologic appearance represents divergent differentiation from neural crest. To our knowledge, the present case represents the first example of pigmented paraganglioma of the kidney.