CASE PRESENTATION: A 62-year-old woman presented to the respiratory department with a 6-month history of progressive difficult breathing. She also complained red rash on scalp, hair and weight loss. She went to a local hospital 2 month ago and was examined by CT, which showed diffuse reticular interstitial thickening and multiple small nodules in both lungs (Fig 1a). She received immunosuppressive therapy, yet didn’t respond well. Physical examination found alopecia and red patches on calvarias. Lung auscultation revealed decreased respiratory sounds bilaterally, with dry crackles. Arterial blood gas analysis revealed hypoxemia. CT scan revealed bilateral plural effusion plus a diffuse reticular, nodular and ground-glass pattern (Fig 1b). Serum virology and autoantibody test were negative. Several of serum tumor markers turned out to be elevated. Cytological analysis of BALF showed total cells 0.21×106/mL, macrophagocyte 68%, lymphocyte 28%, segmented cell 4%. Bacterial and fungal BALF cultures were negative, including PCP microscopic and PCR examination. Histopathology of biopsy obtained from cervical skin confirmed to a poorly differentiated, signet ring cell-type adenocarcinoma metastasis (Fig 2a). Gastroscopy revealed two thicken folds with erosive mucosal lesion located on the junction of gastric-antrum and body (Fig 2b). Pathologic analysis of the lesion revealed a signet ring cell-type adenocarcinoma (Fig 2c). On the basis of these findings, poorly differentiated adenocarcinoma of the stomach, with lung lymphangitic carcinomatosis was diagnosed. The patient abandoned further therapy, and died 1 week later.