On retrospective review of the tumor registry files between 1979 and 1992 at the North Iowa Medical Center, six cases of endometrioid adenocarcinoma of the prostate were identified among 1582 cases of prostatic carcinoma. Along with long-term clinicopathologic follow-up, immunohistochemical studies of the prostatic tumor tissues were performed. All six cases of endometrioid carcinoma, together with control cases of benign prostatic hypertrophy (BPH) and ordinary adenocarcinoma of the prostate had unequivocal diffuse positive staining for PSA and similar reactivity to ER-D5 and PS2. Thus, endometrioid carcinoma is most likely derived from the prostate or prostatic urethral duct rather than the utricle. However, due to its unusual initial clinical manifestations, biological behavior, and distinctive histomorphology, the term "endometrioid adenocarcinoma of the prostate" is worth preserving.

The relationship between cholecystectomy and subsequent development of colon cancer was investigated in a case-control study of 165 patients with histologically proven adenocarcinoma of the colon. These patients were from a community in Iowa where incidence of colon cancer was considered to be higher than average in the United States. The relative risk of developing colon cancer after cholecystectomy was shown to be 2.11 (P = .009) for the entire series and 2.91 (P = .002) for the female group. There was a difference of frequency in developing colon cancer after cholecystectomy between the right- and left-sided colons; the relative risk of the right versus the left colon cancer was 2.31 (P = .019). The other factors, including blood group, red cell indices, obesity, serum cholesterol, colonic diverticula, and co-existence of hyperplastic or adenomatous polyp disclosed no significant relation to colon cancer developed after cholecystectomy.

No abstract

Primary adenocarcinoma of the appendix is rare; approximately 200 cases have been reported. Preoperative diagnosis is extremely difficult. We report two cases with two distinctive histologic patterns of adenocarcinoma resulting in different outcomes. The classification and treatment of primary epithelial malignant tumors of the appendix are also discussed.

A 75-year-old man developed neurilemmoma of the left eighth cranial nerve, adenomatous polyp of the sigmoid colon, adenocarcinoma of the prostate, mixed cell type lymphoma of the right neck, and infiltrating ductal carcinoma of the right breast metachronously during a period of 38 years. The cancer of the right breast occurred 7 years after the long-term stilbestrol treatment of prostatic carcinoma, which suggests a causal relationship between the hormonal therapy and development of breast carcinoma.