The tip of the iceberg: a giant pelvic atypical lipoma presenting as a sciatic hernia

Abstract

Background: This case report highlights two unusual surgical phenomena: lipoma-like well-differentiated liposarcomas and sciatic hernias. It illustrates the need to be aware that hernias may not always simply contain intra-abdominal viscera.

Case presentation: A 36 year old woman presented with an expanding, yet reducible, right gluteal mass, indicative of a sciatic hernia. However, magnetic resonance imaging demonstrated a large intra- and extra-pelvic fatty mass traversing the greater sciatic foramen. The tumour was surgically removed through an abdomino-perineal approach. Subsequent pathological examination revealed an atypical lipomatous tumour (synonym: lipoma-like well-differentiated liposarcoma). The patient remains free from recurrence two years following her surgery.

Conclusion: The presence of a gluteal mass should always suggest the possibility of a sciatic hernia. However, in this case, the hernia consisted of an atypical lipoma spanning the greater sciatic foramen. Although lipoma-like well-differentiated liposarcomas have only a low potential for recurrence, the variable nature of fatty tumours demands that patients require regular clinical and radiological review.

Figure 1

Photograph demonstrating obvious swelling in right gluteal area.

Figure 2

Sagittal T1-weighted MRI section (arrow indicating tumour).

Figure 3

Transverse T1-weighted MRI section (arrow indicating tumour).

Figure 4

View of the tumour within the pelvis (arrow demonstrating tumour).

Figure 5

View of the tumour within the pelvis (arrow demonstrating tumour).

Figure 6

Delivery of the tumour via the perineal wound.

Figure 7

Gross appearance of the tumour after excision.