The tip of the iceberg: lipomatous tumours presenting as abdominal or pelvic wall hernias

Abstract

Liposarcomas are the most common soft tissue sarcoma. They occur mainly in the thigh or retroperitoneum. Due to their size, lipomatous tumours can herniate either through the abdominal wall or in the groin. The part of the tumour that herniates represents only the ‘tip of the iceberg’, as the main part of the tumour is not detectable clinically and is often underestimated. Due to their deep location, lipomatous tumours are often large at the time of presentation and therefore their surgical management can be challenging. Furthermore, due to their delayed presentation, there is a higher risk of de-differentiation. In this pictorial review, we discuss different presentations of herniating lipomatous tumours according to the location of the abdominal wall defects. We aim to cover a wide spectrum of hernia defects including inguinal, ventral, lumbar, sciatic and ischiorectal hernias. We also present cases of tumours within the psoas compartment ‘herniating’ from the pelvis into the thigh. In case of a palpable lump, the first diagnostic step is to perform an ultrasound. If the herniating tissue is not fully accessible with ultrasound, additional cross-sectional imaging by CT or MRI is warranted. In this article, CT and MRI findings in lipomatous tumours are addressed and the use of contrast enhanced sequences in MRI is discussed. Patients’ outcome depends not only on adequate diagnosis but also on the correct route of tissue sampling for histology and oncological resection to prevent local recurrence and loss of function. Therefore, referral to a specialised sarcoma treatment centre is key and needs to be done before biopsy.

Inguinoscrotal Hernia: An Unusual Presentation of Retroperitoneal Liposarcoma

“…Liposarcoma presenting within an inguinal hernia is rare and may signify a deeper underlying issue. The primary tumor might not be readily identifiable through clinical examination [ 9 ]. The retroperitoneal origin of the tumor is often indicated by the displacement of adjacent retroperitoneal organs or major vessels as seen on CT or MRI scans.…”

Large Intermuscular Lipoma Presenting as a Groin Hernia

“…When located over the anterior abdominal wall, the lump may not be obvious until the lipoma attains a large size [ 2 ]. The larger sized lesions can herniate through the abdominal wall or groin, however, the herniating part may only represent the “tip of the iceberg” and the remainder still undetected [ 6 ].…”

“…Due to their deep location, intramuscular and intermuscular lipomas are often large at diagnosis and rarely may present as hernias, which may only represent the “tip of the iceberg” [ 6 ]. A delayed presentation of these lipomas may increase the risk of de-differentiation [ 6 ]. Therefore, a high index of suspicion, timely diagnosis, and careful surgical excision are required to treat them.…”