Abdominal Wall Neoplasms

R. Brooke Jeffrey, MD

Key Facts

Terminology

Malignant abdominal wall tumor, not arising from normal constituents of abdominal wall

Imaging

Best diagnostic clue
- Spherical soft tissue density mass(es) within abdominal wall muscles or subcutaneous tissues
Best imaging tool: CECT, US, or MR
Protocol advice
- Always consider hernia before performing biopsy of abdominal wall mass

Top Differential Diagnoses

Abscess
Hematoma
Hernia
Varices
Endometriosis

Pathology

10% of patients with Gardner syndrome present with abdominal wall neoplasms

Clinical Issues

Most common signs/symptoms
- Palpable mass
- May be asymptomatic (lipoma or desmoid) or painful (metastases)
Clinical profile
- Patient with known malignancy or lymphoma (especially immunocompromised patients)

Diagnostic Checklist

Consider spigelian hernia if mass is lateral to rectus sheath

(Left) Axial NECT in a patient with a palpable right flank mass 2 years after a left colectomy for stage III mucinous adenocarcinoma of the descending colon. Note the densely calcified right flank mass

, proven on biopsy to be a metastasis of colon cancer. (Right) Axial NECT in the same patient demonstrates a calcified midline mass

. Given the fact that the lesion arose in close proximity to the prior surgical incision, this possibly represents a tumor implant at the time of colectomy.

(Left) Axial CECT in a 50-year-old woman undergoing routine surveillance after a left nephrectomy for stage IIA renal cell carcinoma reveals bowel loops

occupying the left renal fossa. Note the hypervascular abdominal wall mass

seen laterally, which was proven on biopsy to be a metastasis from renal cell carcinoma. (Right) Axial CECT in a 19-year-old patient with Gardner syndrome reveals a solid mass

involving the lower rectus muscle, surgically proven to be a desmoid tumor.

TERMINOLOGY

Definitions

Benign or malignant abdominal wall tumor not arising from or metastatic to normal constituents of abdominal wall, including skin, subcutaneous fat, or muscle

IMAGING

General Features

Best diagnostic clue
- Spherical soft tissue density mass(es) within abdominal wall muscles or subcutaneous tissues
Size
- Few mm to several cm
Morphology
- Spherical or oblong

Imaging Recommendations

Best imaging tool
- CECT, US, or MR
Protocol advice
- Always consider hernia before performing biopsy of abdominal wall mass

Radiographic Findings

Radiography
- Abdominal wall calcifications within metastases from adenocarcinoma and serous cystadenocarcinoma of ovary

CT Findings

Lipoma
- Subcutaneous fatty mass
Most primary tumors and metastases are enhancing, well-defined soft tissue masses
Some sarcomas and metastases are hypervascular
- Renal cell carcinoma
Both mucinous colon cancer and serous ovarian carcinomas may calcify
Dermoids
- Soft tissue attenuation
- Often infiltrative appearance