Definition of Omental Caking
Thickening of the omentum resulting from localized or diffuse infiltration of omental fat by soft tissue density mass is referred as “omental caking”.
It is a radiological sign, which is often identified in CT scan.
Involved Anatomical Structure in Omental Caking
Greater Omentum – an extension of the anterior and posterior visceral peritoneum.
Causes of Omental Caking
Metastatic involvement (Commonest)
- Ovarian carcinoma (commonest cause)
- Colonic carcinoma
- Gastric carcinoma
- Pancreatic carcinoma
- Others: Endometrial carcinoma, Bladder cancer, Renal cell carcinoma, Hepato-biliary malignancies, Melanoma, Lung cancer, Breast cancer
4 routes of spread to omentum:
- Direct extension
- Intraperitoneal seeding
- Hematogenous spread
- Lymphatic spread
Primary malignancies and benign tumors of omentum (Rare)
- Abdominal mesothelioma
- Haemangiopericytoma
- Leiomyoma
- Leiomyosarcoma
- Gastrointestinal stromal tumour (GIST)
- Lipoma
- Liposarcoma
- Neurofibroma
- Fibrosarcoma
- Small round cell tumours
Infections
- Tuberculous peritonitis
- Actinomycosis
- Coccidiodomycosis
- Non-tuberculous mycobacterial infection
- Histoplasmosis
- Omental paragonimiasis
Unusual Etiologies
- Myelofibrosis
- Sclerosing omentitis
- Amyloidosis
Further Investigation in Omental Caking
Percutaneous CT or US-guided biopsy for primary diagnosis and staging.
References
Mamlouk MD, vanSonnenberg E, Shankar S, Silverman SG. Omental cakes: unusual aetiologies and CT appearances. Insights into Imaging. 2011;2(4):399-408. doi:10.1007/s13244-011-0105-4.