Large pelvic accessory spleen mimicking an adnexal malignancy in a teenagegirl

A large pelvic accessory spleen in a teenage female is rare and may be misd iagnosed as an adnexal tumor. A 17-year-old girl, gravida 0, had suffered f rom intermittent and dull pain in the lower abdomen for I month. Laboratory evaluation showed a low platelet count (136,000/muL). Abdominal sonography showed a large solid mass situated at the right pelvis, containing abundan t vascular supply with low resistant blood flow. At laparotomy, an accessor y spleen fed by a tortuous vascular pedicle from the omentum was found and then excised. Histopathologic examination revealed congestive accessory spl enomegaly. Follow-up platelet count returned to normal levels (37-1,000/muL ). The importance of including accessory spleen in the differential diagnos is of a solid adnexal tumor with thrombocytopenia is emphasized.