Photoclinic Diagnosis: Primary Adenocarcinoma of the Appendix Presenting as a Buttock Mass

A64-year-old man from southern Iran presented with a one-year history of intermittent right sided lower extremity pain and limping. Since three months prior to his referral, pain had mainly focused in his right hip and buttock. His family and past medical histories were unremarkable. The patient was not receiving any medications. On physical examination, he was conscious and had no difficulty with speech, vision, or respiration. His vital signs were within normal limits. Cardiopulmonary examination was unremarkable and there was no evidence of lymphadenopathy or organomegaly. However, a large nontender mass was found in his right buttock. The patient had two pelvic X-rays, which were reported normal. Abdominopelvic ultrasonography and computed tomography (CT) revealed a dumble-shaped mass with solid and cystic components. The mass involved the right iliac fossa and buttock (Figure 1). Preoperative complete blood count, liver and renal function tests, chest X-ray, and erythrocyte sedimentation rate were all normal.