Acute appendicitis with abscess stimulating carcinoma of the sigmoid.

Acute appendicitis with abscess often produced a distinctive extrinsic pressure deformity of the cecum. If the abscess is large or disseminated, other parts of the gastrointestinal tract may be secondarily involved. Abscesses usually produce extrinsic compression defects with benign radiologic characteristics, but occasionally the lesions may simulate malignant disease. Even careful evaluation of the clinical symptoms and signs may not be helpful in the differentiation of benign from malignant disease. Three examples of atypical acute appendicitis are described in patients with clinical and radiologic findings strongly suggestive of malignant disease.