[A case of jejunal metastasis from pulmonary adenocarcinoma occurring as perforative peritonitis].

On first admission on June 5, 1989, pulmonary adenocarcinoma of left S3b in a 62-year-old male had already metastasized to the brain and the clinical stage was T2N2M1. Radiation therapy for the metastatic brain lesion was very successful but chemotherapy for the primary lesion was not effective. He was discharged on August 24, 1989. He was readmitted to our hospital on Jan. 5, 1990 because of severe abdominal pain. His chest roentgenogram showed free air under the diaphragm. An emergency laparotomy was performed, because perforation of gastrointestinal tract was suspected. At operation, two localized tumors were found, one located in the jejunum approximately 20 cm distal to the ligament of Treitz, accompanied by perforation and another approximately 20 cm distal to the above lesion in the mesentery. The resected specimen of the perforated lesion demonstrated a deep and large ulcer, compared to the tumor size, similar to a submucosal tumor, accompanied by bridging folds. The pathologic interpretation was adenocarcinoma of the lung metastatic to the jejunum and mesentery. Primary lung cancer metastasizes to a wide variety of organs, but metastasis to the small intestine is uncommon, even on postmortem examination. Furthermore, it is rare that the metastatic lesion causes abdominal symptom leading to laparotomy.