Urinary bladder malignant paraganglioma with vertebral metastasis: a case report with literature review
In September 2005, a 53-year-old woman complaining of odynuria over a week was admitted to the Department of Urinary Surgery at the Affiliated Zhongshan Hospital of Dalian University. The pain began as an odd sensation described as a pricking pain in the lower abdomen without radiating pain. This pricking pain happened suddenly, without any motivation or signs. There was no history of hematouria, pyuria, or low-back pain, and there was no precipitating trauma nor aggravating or alleviating factors.\nThe patient appeared healthy and had a blood pressure of 21.3/12.0 kPa (160/90 mmHg). In the following physical examination, there was no tenderness to palpation over the whole abdomen, nor were any other positive physical signs found. Abdominal sonography revealed a heteroplastic, hyperechoic mass in the right anterior wall of the urinary bladder, which was confirmed on subsequent computed tomography (CT) scan. The CT documented the presence of a hypervascularized mass approximately 4.7 cm in diameter with a homogeneous aspect.\nThe patient underwent partial cystectomy for bladder tumor. During surgery, the tumor appeared as an intensely vascularized mass (6 cm × 5 cm × 4 cm) located in the right anterior wall of the urinary bladder. No apparent margin invasion and local metastasis were found, and these findings were confirmed by subsequent pathologic examination. The biopsy in the remaining proximal part of the urinary bladder revealed that there was no tumor tissue left. The tumor histology revealed an alveolar pattern with nests of neoplastic cells surrounded by vascularized connective tissue septa, and no vascular or capsular invasion was found. The tumor was composed of three cell types: epithelioid cells, surrounding spindle-shaped sustentacular cells, and scattered ganglion cells. The epithelioid cells were arranged in nests. Immunohistochemical staining was positive for chromogranin A, neuron-specific enolase, and synaptophysin () and negative for cytokeratin. No signs of necrosis were found. Based on the pathologic findings, the definite diagnosis was paraganglioma. The patient's postoperative course was uncomplicated, and she was discharged on the eighth day after surgery. No further therapy was thought to be indicated.\nFollow-up at 1 year showed complete resolution of preoperative symptoms, and abdominal sonography revealed no evidence of local recurrence. However, at 19 months of follow-up, the patient came back to the hospital and reported a month-long history of increasing back pain radiating along the intercostal space. She got abrupt paralyzing numbness in both lower limbs as well. The patient reported that the pain was usually aggravated at night. She also reported a month-long history of night sweat and hectic fever. In the physical examination, there was apparent tenderness on palpation of the spinous process and the nearby area of the sixth and seventh thoracic vertebra. The measurement of muscle strength revealed grade 3/5 flexion at the hips and extension at the knees, and grade 4/5 dorsiflexion and plantar flexion at the ankles. Hypesthesia was present under the fourth lumbar nerve level in both lower limbs as well as in the saddle area.\nA thoracic CT scan showed bone damage with low density in the sixth thoracic vertebra, where there was a soft tissue mass protruding into the vertebral canal and compressing the spinal cord (). Total body Tc-99m bone scan revealed a well-circumscribed area of intense uptake in the same region ().\nBecause of the vertebral tumor, the patient underwent tumor excision together with allograft bone transplantation and spinal fusion. The surgery confirmed the tumor in the sixth thoracic vertebra. Pathologic examination confirmed the diagnosis of vertebral metastasis of the malignant paraganglioma, which had the same histologic pattern and immunohistochemical findings as the paragangioma in her urinary bladder 19 months before. The patient's postoperative course was uncomplicated, and she was discharged on the 14th day after surgery. Follow-up at 1 year and 1.5 years showed complete resolution of preoperative symptoms and no local recurrence or metastasis according to CT scan and total body metaiodobenzylguanidine (MIBG) scintigraphy.