Case 9
History:
46 year old male with right lower quadrant pain
Findings:
Abdominal CT scan shows a calcified soft tissue lesion in the right lower quadrant with desmoplastic reaction around it.
Diagnosis:
Carcinoid tumor
Discussion:
Carcinoid tumors are the most common gastrointestinal endocrine tumors accounting for approximately 55% of such neoplasms. Typical symptoms include gastrointestinal bleeding, abdominal pain, bowel obstruction from tumor growth or tumor-induced mesenteric fibrosis or symptoms arising from tumor secreted hormones. Tumors can be found anywhere from the stomach to the rectum and are most common in the appendix, ileum and rectum. In addition, desmoplastic reaction from mesenteric spread resulting in intestinal kinking, obstruction and rarely vascular compromise can be seen.
Appendiceal tumors account for nearly half of the tumors. They are usually small, solitary and benign. Colorectal carcinoids have a similar benign course and are usually asymptomatic. In contrast, small bowel and bronchial carcinoids have a more malignant course. Local transmural invasion, early metastases to lymph nodes and liver and symptoms from hormone secretion are common.
Metastases are found in fewer than 2% of tumors less than 1 cm in diameter but in nearly 100% of tumors greater than 2 cm.
References:
- Eisenberg RL. Gastrointestinal Radiology: A Pattern Approach,
3rd Edition. Lippincott-Raven, Philadelphia; 1996:497-498. - Lee JK, Sagele SS. Computed Body Tomography with MRI Correlation,
2nd Edition. Raven, New York; 1989:495-496. - Harrison TR. Principles of Internal Medicine, 13th Edition.
McGraw-Hill, New York; 1994:1537.
