Background: Lung cancer accounts for more deaths than any other cancer in the country for both men and women.. Here we describe a case of rectus abdominis muscle, small bowel and mesenteric metastasis with poorly differentiated lung adenocarcinoma at the time of diagnosis.
Case Report: This is a case of 51 year old male patient who came with complains of severe abdominal pain for 3 days. He had a workup done for hemoptysis (over 2 months) including a CT chest which showed a 3.1×2.7cm cavitary lesion but the following bronchoscopy for malignancy was negative. He had a 30 pack year smoking history and had quit 10 years back. CT abdomen showed dense lobular mesenteric mass likely representing hemorrhagic mass seen in the right aspect of the mesentery. A second lesion was seen at inferior lateral aspect of the right rectus muscle which likely represents hemorrhagic lesion with hemoperitonuem. Pathology result came back as most consistent with metastatic poorly differentiated pulmonary adenocarcinoma. The patient is undergoing radiation treatment at present.
Conclusions: There are very few case reports of lung cancer presenting with small bowel obstruction or perforation as the initial presentation. Skeletal muscle metastasis although rare, has been described to forearm, gluteal and psoas muscle. Our case presented as a hemorrhage resulting in overlying bruise which is not described before. Treatment options for such cases are not clear but as the patients usually have advanced disease at the time of diagnosis. Multimodality treatment options including surgical excision, chemotherapy and radiotherapy have been tried with mixed results.

Keywords: lung adenocarcinoma, Metastasis, Rectus Abdominis, Mesenteric