Endocrine Abstracts

Background: Pheochromocytoma (PHEO) and paraganglioma (PGL) are the tumors of adrenal medulla and extra adrenal ganglia respectively. Most of these PHEO/PGL are benign and may become malignant, if remain undiagnosed/untreated for a longer time. Vaginal PGL are extremely rare. There is not much published literature on vaginal PGL.

Objective: To carry out biochemical and genetic analysis of the patient with MIBG negative malignant vaginal PGL.

Methods: Blood sample was collected from the patient lying supine for at least 30 min. Plasma free metanephrines (MN, NMN and 3-MT) were estimated using HPLC. SDHB, C and D genes were sequenced after amplification from the DNA extracted from peripheral blood.

Results: 22 years female attending endocrine clinic complained of headache, palpitation for 6 years. She had visual disturbance for 1 month. She had tender firm mass involving anterior vaginal wall, hard non tender mass along right lateral pelvic wall. Her MIBG scan was done and it was found negative. Her NMN was 6.800 pg/ml (reference range <800 pg/ml). Owing to high NMN levels MIBG and DOTANOC scan was done. MIBG scan was negative and DOTANOC scan showed increased uptake in pelvic mass, along bilateral sympathetic chain and in left femur. MRI showed solid mass arising from proximal vagina extending along right internal iliac vessels.USG abdomen showed B/l polycystic ovaries, vaginal mass 4.5×4.5 cm and Rt. parametrical mass 2.8×2.9. Her genetic analysis showed 11 bp (AACACTCTAGC) deletion of SDHB Ex-4 from c.325 to c.335. Her family history was negative for the disease from maternal and paternal side. Genetic analysis of her family members was also done. Her father was found positive for the same deletion.

Conclusion: The biochemical and genetic analysis should be carried out in the patients with MIBG negative imaging. In this case the mutation showed variable expression.