Contributed by Kathryn McFadden, MD
Published on line in June 2002
The patient is a 62 year old female who presented with progressively worsening abdominal/pelvic pain over a period of 6 weeks. She had experienced minor intermittent pain in that area after undergoing laminectomy in 1993 but was now in moderate to severe constant pain. Review of symptoms was positive for deep abdominal and sacral pain and negative for recent weight loss, lower extremity weakness, and bladder/bowel dysfunction. On physical exam the patient had normal strength and sensation throughout and a normal gait, however there was a large, palpable mass posterior to the sacrum. Because she had a known history of diverticulitis, CT scans of the abdomen and pelvis were performed in preparation for colonoscopy.
Plain film of the region showed lytic destruction of the sacrum with aberrant soft tissue masses both anterior and posterior to the sacrum (Figure 1). CT of the pelvis (Figure 2) showed a 7.0 cm, lobulated mass enveloping the sacrococcygeal area with associated destruction of bone. The rectosigmoid colon and bladder were seen to be unaffected. Pelvic lymph nodes were not enlarged. CT scan of the abdomen was negative. MRI (Figures 3 and 4) likewise revealed a lobulated mass in the sacrococcygeum measuring approximately 7.5 x 7.0 x 6.0 cm. The mass appeared to arise in the coccygeal bone with both anterior and posterior exophytic extensions into surrounding tissue. There was no involvement of S3 or the thecal sac to the level of S2-3.
The patient underwent CT guided biopsy to confirm the preliminary radiographic diagnosis. A radical excision of the sacrum from S3 to the coccyx was performed.