A juvenile case of pulmonary lymphangitic carcinomatosis caused by sigmoid colon cancer with a component of micropapillary carcinoma

Micropapillary carcinoma is known to be associated with a poor prognosis and high propensity for lymphovascular invasion and lymph node metastasis. Case reports on colorectal micropapillary carcinoma are relatively rare. We report here a 26-year-old woman who had sigmoid colon cancer with a micropapillary component. We made the diagnosis of pulmonary lymphangitic carcinomatosis but could not identify the primary lesion. We gave her chemotherapy as an occult primary cancer. But her respiratory condition did not improve and she died of respiratory failure. Autopsy was performed after her death. The final diagnosis was pulmonary lymphangitic carcinomatosis and multiple lymph node metastases of sigmoid colon cancer with a component of micropapillary carcinoma.