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.
- Pathology 02/2010; 42(2):182-4. · 2.66 Impact Factor
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ABSTRACT: Localized malignant mesothelioma is very uncommon and mainly arises in pleura and peritoneum, and preferentially occurs in older adults. In this article, we report a case of a Localized malignant mesothelioma that was developed in the stomach of a 6-year-old boy. This boy was admitted to hospital for anemia. An epigastric mass was palpated through systemic physical examination and MR scanning demonstrated an 8×6 cm-sized, well-defined elliptic mass at gastric corpus. Partial resection of the stomach was performed for this boy and no nodules were found on the liver, peritoneum, and other abdominal sites in surgery. In view of the morphological and immunohistochemical findings, a diagnosis of localized malignant mesothelioma, epithelial type was made. This is the first case report of localized malignant mesothelioma arising in the stomach of a child. Accumulation of more cases of malignant mesothelioma involving gastrointestinal tract and longer follow-up of the patients are necessary to further characterize the features of this rare disease.International journal of clinical and experimental pathology. 01/2014; 7(5):2636-40.
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ABSTRACT: Herein is reported a highly rare case of combined adenomatoid tumor and well differentiated papillary mesothelioma of the omentum. A 45-year-old Japanese man was incidentally found to have a mesenteric mass during abdominal ultrasonography. Grossly, a well-circumscribed and non-encapsulated tumor, measuring 24 × 23 × 22 mm, was located in the omentum with no obvious invasion to the surrounding stomach and pancreas. Microscopically, the tumor consisted of two histological distinct components; the majority of it showed irregular arrangement of numerous cysts lined by a single layer of flattened or epithelioid cells and the multifocal minor component exhibited prominent papillary protrusions lined by a single layer of cuboidal cells with relatively uniform nucleus. Immunohistochemically, the tumor cells were diffusely positive for cytokeratin (AE1/AE3), vimentin, calretinin, D2-40 and WT-1, and negative for epithelial membrane antigen (EMA), desmin, S-100 protein and CD68. Ki-67 labeling index of the tumor cells was <5%. The postoperative course was uneventful, though he has not received any adjuvant therapy. Despite the rarity, recognition of such combined cases of mesothelial lesions is important to prevent overdiagnosis.Pathology International 10/2011; 61(11):681 - 685. · 1.72 Impact Factor