CASE 18539 Published on 24.04.2024

Pseudomyxoma pleuri – A rare manifestation of pseudomyxoma peritonei


Chest imaging

Case Type

Clinical Case


Megha J., H. N. Pradeep, Raghu K. H., Manveena D., Kiran H. Nadagaddi

Mysore Medical College and Research Institute, Mysuru, Karnataka, India


52 years, female

Area of Interest Abdomen, Oncology, Thorax ; Imaging Technique CT, MR, Ultrasound
Clinical History

A 52-year-old female with a known case of carcinoma caecum who underwent right hemicolectomy and chemotherapy for mucinous adenocarcinoma of the caecum, presented with complaints of difficulty in breathing and cough for 1 month. Reduced breath sounds in the right lung field were found during the respiratory system evaluation. Standard lab tests were within normal limits.

Imaging Findings

Chest radiograph (X-ray) showed near total opacification of the right thorax and mild cardiomediastinal shift to the left (Figure 1).

Abdominal and thoracic ultrasonography (USG) showed multiloculated pleural effusion and loculated non-mobile echogenic ascites with scalloping of the hepatic margins (Figures 2a and 2b).

Thoracic contrast-enhanced computed tomography (CT) showed massive multiloculated peripherally enhancing collections with few specks of calcification in the right hemithorax with a near complete collapse of the right lung and cardiomediastinal shift to the left (Figures 4a, 4b and 4c).

Abdominal contrast-enhanced CT showed few loculated hypodense collections with few specks of calcifications in the right subhepatic region with extension along falciform ligament, causing scalloping of the liver surface.

T2-weighted magnetic resonance imaging (MRI) showed multiloculated hyperintense collections in the right hemithorax with mild cardiomediastinal shift to the left (Figures 5a, 5b and 5c). T1 contrast MRI showed multiloculated peripherally enhancing collections and few loculated hyperintense collections in the subhepatic region (Figures 6a and 6b). The pleural extension appeared as a thickened pleura with multiple lobulated masses.

Peritoneal and pleural aspiration showed abundant mucinous material. Cytological examination of the fluid showed mucus with cohesive aggregates of muco-producing epithelial cells (Figure 7).


According to an American study published in 2000, the intrathoracic spread of pseudomyxoma peritonei is a rare condition, occurring in only 5.4% of cases [1]. Diffuse collections of gelatinous fluid and mucinous implants on the peritoneal surface, omentum, and pleura are characteristic of pseudomyxoma peritonei, pleuri. The primary tumour in our case is mucinous adenocarcinoma of caecum that perforates and spreads mucus-producing cells throughout the abdomen and pleura [2,3]. Imaging plays a major role in the diagnosis of pseudomyxoma pleuri and peritonei.

Iatrogenic perforation of the diaphragm, occurring during sub-diaphragmatic peritonectomy, is the most frequent mechanism for intrathoracic extension [1,4]. Congenital pleuroperitoneal communications, direct invasion of the diaphragm, and haematogenous dissemination can also lead to pleural extension [1]. The synchronous pleural involvement of pseudomyxoma peritonei, in our case, resulted from the massive mucinous tumour invading the diaphragm and extending into the pleural space.

It has to be differentiated from mesothelium carcinomatosis, where diffuse or nodular thickening of the peritoneal serosa with infiltration of the greater omentum, mesenteric masses, and pleural plaques is noted [7].

The current course of treatment for pseudomyxoma pleuri and peritonei involves multiple surgical debulking and cytoreductive surgery with hot intraoperative intraperitoneal chemotherapy [1]. Bicavitary hyperthermic chemoperfusion is a treatment for pleural involvement [1,5].

Differential Diagnosis List
Pseudomyxoma peritonei with pseudomyxoma pleuri
Soft tissue neoplasms with myxoid changes
Mesothelium carcinomatosis
Peritoneal carcinomatosis
Cystic lymphangioma
Final Diagnosis
Pseudomyxoma peritonei with pseudomyxoma pleuri
Case information
DOI: 10.35100/eurorad/case.18539
ISSN: 1563-4086