[Extra-adrenal pheochromocytoma: report of 4 cases]

Paraganglioma (pheochromocytoma) of the urinary bladder: A systematic review with a diagnostic, management and treatment algorithm

Introduction:

Paraganglioma of the urinary bladder is a rare but well-documented tumour. Herein, we provide the largest, comprehensive systematic review of the literature and aim to increase familiarity with this rare but significant neoplasm.

Methods:

A systematic review of the literature was conducted on the NCBI PubMed database. The search criteria were not limited to any specific years or languages. There were 418 articles between January 1953 and August 2020, of which 255 case reports were selected.

Results:

Paragangliomas of the urinary bladder most commonly occurred in Caucasians in the fifth decade of life, most commonly presenting with haematuria and variations of ‘micturition attacks’. Eighty percent of tumours were functionally active. The mucosa was normal in 91% of patients. In all, 25% of tumours were treated with transurethral resection alone, 65% had partial cystectomy and 5% had radical cystectomy. Alpha-blockers were administered pre-operatively in 38% of patients and the risk of intra-operative hypertensive crisis was over three times greater in those who did not receive an alpha-blocker. The tumour was confined to the bladder in 75% of cases. Metastasis occurred in 20% of cases, most commonly to iliac nodes. The mean follow-up time was 26.5 months. In cases that documented follow-up, 18.6% had recurrence, most commonly in lymph nodes and bone.

Conclusion:

All patients presenting with micturition attacks or haematuria with a computed tomography showing an enhancing, well-defined submucosal bladder lesion and/or cystoscopy showing a lesion with normal overlying mucosa should be worked up for a possible paraganglioma of the urinary bladder.

Level of evidence:

Not applicable

Hyperfixation diffuse de la graisse brune à la tomoscintigraphie par émission de positons couplée à la tomodensitométrie (TEP-TDM) dans l’exploration d’un phéochromocytome extra surrénalien

We report an observation of strong bilateral uptake on a PET-CT scan compatible with activation of brown adipose tissue in a patient with extra-adrenal pheochromocytoma. A 42-year-old man was hospitalized for hypersudation together with weight loss and palpitations. Heart rate was 120 bpm and fasting blood glucose 1.36 g/l. Endocrine explorations revealed elevated serum chromogranine which reached 517 ng/ml (19-38). The norepinephrine level reached 49.7 nmol/l (<4.00) and urinary norepinephrine and normetanephrine levels reached 13977 nmol/24h (<414) and 32 micromol/24h (0.4-2.5) respectively. The thoraco-abdominal and pelvic scan showed a 6 cm diameter paraaortic hypervascularized mass with an infiltrative lesion of both perirenal area and mediastinal tissue without adenopathies. The abdominal MRI revealed the mass with a low intensity signal in T1 and a slight high intensity signal in T2. MIBG and octreoscan scintigraphies were negative. 18F-DG PET showed intensed uptake in the tumor mass together with intense, diffuse and bilateral uptake above and below the diaphragm. The mass was resected. Histological examination of the surgical specimen confirmed the diagnosis of extra-adrenal pheochromocytoma with an index of 13% cellular proliferation without cell atypia. There was a hypervascularization with small islets of brown adipose tissue in the perirenal fat. Both plasmatic and urinary catecholamines decreased to the normal range after the operation and PET-scan normalized. Bilateral spread of the radiotracer uptake was probably due to brown adipose tissue activation by excessive sympathetic stimulation induced by catecholamines released by the tumor.