Localized Malignant Mesothelioma

Abstract

Localized malignant mesotheliomas are uncommon sharply circumscribed tumors of the serosal membranes with the microscopic appearance of diffuse malignant mesothelioma but without any evidence of diffuse spread. Little is known about their behavior. We report 23 new cases. The mean age at presentation was 63 years, and the sex ratio was approximately 2:1 (male/female). Twenty-one tumors were pleural and 2 were peritoneal. Sixteen tumors reproduced microscopic patterns of diffuse epithelial mesotheliomas, 6 had mixed epithelial and sarcomatous patterns, and 1 was purely sarcomatous. After surgical excision of the tumor, 10 of 21 patients with follow-up data were alive without evidence of disease from 18 months to 11 years after diagnosis. Patients who died had developed local recurrences and metastases, but none had diffuse pleural spread. Localized malignant mesotheliomas should be separated from diffuse malignant mesotheliomas because of their localized presentation, quite different biologic behavior, and far better prognosis.

Malignant Peritoneal Mesothelioma Masquerades as Peritoneal Metastasis on 18F-FDG PET/CT Scans; a Rare Diagnosis that Should Not Be Missed

“…It can arise from either parietal or visceral peritoneum. A solitary circumscribed peritoneal nodule/mass (as in the present cases) is termed Blocalized^MPM, which is rarer than the Bdiffuset ype but has a much better prognosis because the tumor can be easily resected [10]. However, in the setting of extensive metastasis (as in the present cases), a curative aim of treatment is not possible.…”

A localized malignant mesothelioma of the visceral pleura treated with minimal resection of the lung

“…[1,9] Resection is considered the treatment of choice for LMM of the pleura. Allen et al [6] reported that almost half of the patients (10 out of 21) were alive after resection 18 months to 11 years after the diagnosis. On the other hand, the other half (n=11) died due to local recurrences and metastases.…”

“…[1,3,[7][8][9] Although the role of asbestos exposure in the development of DMM has been described in many reports, a history of asbestos exposure has been detected in only a small proportion of patients with LMM. [4,6,7] Our patient had no known history of asbestos exposure. The clinical presentation of patients is mostly insignificant, and they are generally asymptomatic.…”

“…[5] The US-Canadian Mesothelioma Reference Panel described the largest series of LMM of the pleura, which included 23 patients, in 2005. [6] The criteria used to diagnose these cases was as follows: (i) Radiologic, surgical, or pathologic evidence of a localized serosal/subserosal (but not organcentered) tumor mass without evidence of diffuse, serosal spread; (ii) A microscopic pattern identical to that found in ordinary DMM. Allen et al [6] also identified 22 previously reported cases in the review of the literature.…”

Epithelioid Lesions of the Serosa

“…Most reported cases of localized MM have developed in the pleura or as intrapulmonary or mediastinal tumors, but peritoneal localization and even hepatic and pancreatic tumors with visceral peritoneal origin have also been reported. 3,[74][75][76][77] All histologic subtypes and different morphologic patterns of MM have been described in association with localized MM. Localized MM has a better prognosis than diffuse MM because it is often surgically treatable.…”