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Updated: May 12, 2026
Generation and Expansion of Primary, Malignant Pleural Mesothelioma Tumor Lines
Published on: April 21, 2022
Well-differentiated papillary mesothelioma: a clinicopathological and immunohistochemical study of 18 cases with
Xiaochen Chen1, Weiqi Sheng, Jian Wang
1Department of Pathology, Fudan University, Shanghai, China.
Aims:
To present our experience with 18 cases of well-differentiated papillary mesothelioma (WDPM), with an emphasis on its relationship to adenomatoid tumour and multicystic mesothelioma.
Methods And Results:
Eighteen cases of WDPM were retrieved. Twenty cases of multicystic mesothelioma were selected for comparative study. The WDPM patients comprised 14 females and four males, with age ranging from 18 to 60 years (median 37 years). The tumour involved the abdominal or pelvic peritoneum (14 cases), the pleura (two cases), and the testicular tunica vaginalis (two cases). The majority of WDPMs were incidental findings during surgery for a wide variety of conditions. Histologically, 13 cases were consistent with classical WDPM. Two cases had a combined component of adenomatoid tumour, and three cases contained coexisting areas of multicystic mesothelioma. Among the multicystic mesothelioma cases, four had adenomatoid tumour-like foci present in the stroma. Immunohistochemically, all cases of WDPM and multicystic mesothelioma, as well as the coexisting combined components, were positive for mesothelial markers, with a low Ki67 index. This study also showed that WDPM was negative for epithelial membrane antigen and desmin.
Conclusions:
The simultaneous occurrence of WDPM, adenomatoid tumour and multicystic mesothelioma in some cases suggested histogenetic relationships among these three less aggressive mesotheliomas.
Insights
This study reviewed 18 cases of well-differentiated papillary mesothelioma (WDPM), finding connections to adenomatoid tumors and multicystic mesothelioma. These findings suggest a shared origin for these less aggressive mesothelioma types.
Area of Science:
- Pathology
- Oncology
- Surgical Pathology
Background:
- Well-differentiated papillary mesothelioma (WDPM) is a rare neoplasm.
- Its relationship with other mesothelial tumors like adenomatoid tumor and multicystic mesothelioma requires further elucidation.
Purpose of the Study:
- To describe the clinicopathological features of 18 WDPM cases.
- To investigate the potential histogenetic links between WDPM, adenomatoid tumor, and multicystic mesothelioma.
Main Methods:
- Retrospective analysis of 18 WDPM cases.
- Comparative study with 20 multicystic mesothelioma cases.
- Histological and immunohistochemical evaluation.
Main Results:
- WDPM commonly affects the peritoneum, pleura, and tunica vaginalis.
- 13 cases were classical WDPM; 2 had adenomatoid tumor components, and 3 had multicystic mesothelioma components.
- Multicystic mesothelioma cases sometimes showed adenomatoid tumor-like foci.
- All mesothelial tumors showed positive mesothelial markers and a low Ki67 index, negative for EMA and desmin.
Conclusions:
- The co-occurrence of WDPM, adenomatoid tumor, and multicystic mesothelioma suggests a shared histogenetic origin.
- These three entities represent less aggressive forms of mesothelioma.
