Abdominal actinomycosis.

PURPOSE: Actinomyces israelii are normal inhabitants in the oral cavity and upper intestinal tract of humans. They rarely cause disease and are seldom reported as pathogens. As a pathogen it causes fistulas, sinuses, and may appear as an abdominal mass and/or abscess. The abdominal mass can masquerade as a malignant process that is very difficult to differentiate, often requiring surgical intervention with resection. Because of difficulty in making a preoperative diagnosis, we undertook this review to determine if all patients require surgical intervention and whether other adjunctive modalities may improve preoperative diagnosis.

METHODS

We report two patients with abdominal actinomycosis, one affecting the sigmoid colon and the other the retroperitoneum, iliac crest region. Both simulated a malignant process and required operations for diagnosis and treatment.

RESULTS

As reported, actinomycotic abdominal masses and strictures can be treated by penicillin alone. Long-term medical treatment seems to be very successful and avoids surgical resection. The difficulty is obtaining a definitive diagnosis.

CONCLUSION

The computed tomographic scan is the most helpful diagnostic modality. Appearance of abdominal actinomycosis is usually a contrast enhancing multicystic lesion as was found in these two patients. Needle aspiration cytology can be fairly accurate in obtaining the diagnosis and is recommended for suspicious lesions.