A 65-year-old female was admitted to the hospital in October 2019, with a chief complaint of chest tightness for 2 months. The patient underwent a complete cytoreductive surgery (CRS) for pseudomyxoma peritonei (PMP) one year ago. Thoracic computed tomography (CT) showed massive pleural effusions on the right side with local atelectasis of the right lung (Fig. 1A). Abdominal CT revealed multiple low-density shadows of unequal size in the liver, and the edge of the lesions were slightly enhanced (Fig. 1B). Combined with previous medical history, she was diagnosed as pleural extension of PMP. After comprehensive assessment, she underwent thoracotomy. The operation revealed 1500ml free mucus in the right pleural space (Fig. 1C), and multiple masses along the pleura, diaphragm and liver (Fig. 1D). Postoperative pathological consisted with low-grade mucinous neoplasm (Fig. 1E).
Chest CT scan showed massive pleural effusions on the right side with local atelectasis of the right lung (A). Abdominal CT scan revealed multiple low-density shadows of unequal size in the liver, and the edge of the lesions were slightly enhanced (B). An open thoracotomy revealed 1500ml free mucus in the right pleural space (C), and multiple masses along the pleura, diaphragm and liver (D). Postoperative pathological showed low-grade mucinous neoplasm (E).
PMP is a rare disease characterized by mucinous ascites from intra-abdominal neoplastic mucin secreting cells proliferating on the peritoneal surface. It usually originates from the appendix or ovary.1 Metastases and extraperitoneal involvement are extremely rare.2 Here, we report a rare case of PMP metastasizing to the pleural and speculate that is the result of diaphragmatic injury caused by the previous operation. The mucus-producing cells migrate to the pleural space through the minor injury and result progressive accumulation of gelatinous material. In addition, the tumor deposits also accumulate at the liver surface close to the diaphragm which supported our speculation.
