A Pelvic Sympathetic Paraganglioma Presenting As an Intestinal Mass and Mimicking a Gastrointestinal Stromal Cell Tumor (GIST)

Presentation Number: LBS-060
Date of Presentation: March 7th, 2015

Maria de Lurdes Matos*1, Jorge Brito2, Rui Bettencourt3, Ana Carvalho4, Silvia Silva4, Ana Crespo4, Paula Tavares4 and Jose Mario Coutinho4
1Hospital Curry Cabral, Lisbon, Portugal, 2Clinica Medica Praia da Vitoria, Praia da Vitoria, Portugal, 3Hospital Angra do Heroismo, Angra do Heroismo, Portugal, 4Hospital Curry Cabral, Lisboa, Portugal

Abstract

Introduction:

Paragangliomas are neuroendocrine tumors of paraganglia, associated with sympathetic tissue in adrenal (pheochromocytomas or PCCs about 80%) and extra-adrenal (sympathetic paraganglioma of thorax, abdomen and pelvis or sPGLs about 20%) or parasympathetic tissue of the head and neck paragangliomas. Sympathetic tumors tend to hypersecrete catecholamines (up to 90%). The diagnosis of a rare disease as pelvic paragangliomas can be a challenge for clinicians.

Case report:

We report a case of a 64-year-old woman, presenting hypertension controlled with losartan/hydrochlorothiazide and elevated catecholamines. 24-h urinary catecholamines:  total 953 μg (14-606), Noradrenaline 85 μg (12-86), Adrenaline 5 μg (2-22) and Dopamine 863  μg (< 498). 24-h urinary fractionated metanephrines: total 4815  μg (329-1263) Metanephrine 288 μg ( 64-302)  Normetanephrine 1562  μg ( 162-527), 3-Methoxytyramine 2965  μg (103-434). Cromogranine A negative. Other hormonal studies were negatives, including 5-HIAA.

I 123-MIBG scintigraphy and 1st abdominal MRI presented no evidence of adrenal or extra-adrenal mass.  In 111- Octreoscan revealed a median low abdominal mass positive for somatostatine receptors. 2nd abdominal MRI presented a pelvic mass, solid with 4 cm suggesting a GIST with exophitic growth. Enterographic CT scan confirmed a pelvic mass related with the sigmoid and/or the small intestine. Colonoscopy showed at 45 cm, a compressive but not invasive mass out of the colon.

The patient underwent preoperative blockade with fenoxibenzamine. Laparotomy was performed with complete resection of the mass, located in the mesenterium adherent to the sero-muscular sigmoid wall. Histopathology confirmed a paraganglioma, capsulated without necrosis or vascular invasion and positive for sinaptophisin, chromogranin A and S100 protein, Ki-67 < 1%.

Discussion:

Our patient presented a pelvic tumor with elevated catecholamines but for differential diagnosis others abdominal tumors, including  GIST were considered.  Abnormal tumor location in pelvis and imaging studies presented no clear criteria for a diagnosis. Paraganglioma was confirmed only after histopathology.

Although most PGL/PCCs are benign, factors such tumor size, tumor location, high metanephrines levels and genetic background are associated with metastatic disease.

This case was a sporadic pelvic paraganglioma in a 64-years-old woman but as the risk of malignancy is greater in sPGLs than PCCs, we consider a genetic study in view of follow-up.

 

Nothing to Disclose: MDLM, JB, RB, AC, SS, AC, PT, JMC