Case Of Well-differentiated Papillary Mesothelioma Research Articles

Histological and immunohistochemical characteristics and p16 status studied by FISH in six incidentally detected cases of well-differentiated papillary mesothelioma of the peritoneum.

Well-differentiated papillary mesothelioma (WDPM) is an uncommon mesothelial neoplasm, which is generally regarded as benign or indolent in terms of its clinical behavior. However, details about WDPM have remained relatively unknown. Therefore, in this study, we examined six incidentally detected cases of WDPM of the peritoneum. All six cases were surgically excised, without any additional therapeutic measures. None of the cases showed recurrence. All six cases presented single lesions and the tumor sizes ranged from 2 to 10 mm. Histologically, all six cases exhibited papillary proliferation of cytologically bland mesothelial cells with a fibroconnective tissue core. One of the cases (Case 6) presented small invasive foci in the stalk. The tumor cells were immunohistochemically positive for mesothelial markers and negative for GLUT-1, p53, and CD146. The Ki-67 labeling index of the tumor cells was lower than 5% at the hot spots. All samples were BAP1-positive. None of the samples presented p16 homozygous deletion, as assessed by fluorescence in situ hybridization (FISH). None of the patients deceased due to WDPM. However, in Case 3, death occurred due to pancreatic cancer. The results of this study indicate the importance of analyzing immunohistochemical markers and p16 status to diagnose WDPM accurately.

Well-differentiated papillary mesothelioma: A 17-year single institution experience with a series of 75 cases

We present our experience with 75 cases of well-differentiated papillary mesothelioma (WDPM) that were diagnosed at our institution between 2000 and 2017. The patients included 58 females and 17 males with age ranging from 18 to 69 years (mean, 42 years). Clinically, the vast majority of WDPMs were incidental findings during laparotomy or laparoscopic surgery for a variety of benign or malignant disease. The lesion manifested as either a small solitary nodule or multiple miliary nodules on the peritoneum or serosal surfaces of internal organs. Histologically, 67 cases were consistent with a classical WDPM, of which 6 cases contained microinvasive foci and 1 case had malignant transformation. Eight cases were hybrid tumors with variable combined component of adenomatoid tumor (n = 4), multicystic mesothelioma (n = 2), and both (n = 2). By immunohistochemistry, besides calretinin, D2-40, CK5/6 and WT1, 94% (29/31) of cases also showed immunostaining for PAX8. In comparison, PAX8 staining was only present in 12% (6/50) of epithelioid malignant mesothelioma selected as control cases. Follow-up information available in 46 cases revealed no signs of tumor progression or local recurrence except for the case that showed transformation to a fully malignant mesothelioma after a period of 15 years. Our comprehensive study further expanded the clinical and histopathological spectrum of WDPM. Compared with epithelioid malignant mesothelioma, PAX8 staining is highly sensitive and specific for WDPM (P < 0.001).

A Case of Well-Differentiated Papillary Mesothelioma of the Male Peritoneum: Successful Treatment by Systemic Chemotherapy

Well-differentiated papillary mesothelioma of the peritoneum (WDPMP) is a rare subtype of epithelioid mesothelioma, which is usually seen in young women without a history of asbestos exposure, and generally, has an indolent course. The relative rarity of this neoplasm in males prompted us to report this case of a well-differentiated papillary mesothelioma of the peritoneum in a 36-year-old man.The patient, who had no history of asbestos exposure, presented with abdominal pain and ascites of unknown etiology. Computed tomography showed abundant ascites with nodules of the peritoneal cavity. Laparoscopic examination revealed a large number of white miliary nodules diffusely covering the peritoneum. Pathology revealed a diagnosis of well-differentiated papillary mesothelioma of the peritoneum, based on histomorphology and immunohistochemistry. The patient started chemotherapy with cisplatin and pemetrexed. After six cycles of chemotherapy, the effectiveness of this chemotherapy was checked by only the computed tomography. PET scan was not used because it is not routinely recommended in WDPMP. Few data are currently available in the literature regarding the performance of the PET scan in WDPMP. Nine months later, the patient was free of symptoms.Based on reviewing the literature and our observations in this case, consultation of other pathologists is highly recommended to discern WDPMP from other disseminated peritoneal diseases, in order to offer the most effective and safe therapeutic strategy. Chemotherapy should be strongly considered if the tumor is unresectable and accompanied by symptoms. Cisplatin and pemetrexed chemotherapy could be a promising therapeutic choice.

Well‐differentiated papillary mesothelioma: a clinicopathological and immunohistochemical study of 18 cases with additional observation

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. 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. The simultaneous occurrence of WDPM, adenomatoid tumour and multicystic mesothelioma in some cases suggested histogenetic relationships among these three less aggressive mesotheliomas.

Well-differentiated papillary mesothelioma of the epididymis in a man with recurrent haematospermia

We present a case of well-differentiated papillary mesothelioma of the epididymis occurring in a 60-year-old man who came to urologic consult after recurrent episodes of haematospermia. The patient denied pain, fever and trauma in genitals. Local examination revealed indolent swelling at the right testicle and ecography localised a well-circumscribed nodule at the epididymis tail, measuring 2 cm in greater diameter, with associated haemorrhagic hydrocele. A nodulectomy was performed and the patient is alive with no evidence of disease 17 months following surgery.

卵巣表層上皮に発生した高分化乳頭状中皮腫の 1 例

卵巣表層上皮に発生した高分化乳頭状中皮腫の 1 例

Laparoscopic Management of Peritoneal Mesothelioma Associated with Pelvic Endometriosis

Objective To describe 3 cases of peritoneal mesothelioma associated with endometriosis that were managed laparoscopically. Design Case series. Setting University and community hospitals. Patients Three women with well-differentiated papillary mesothelioma of the peritoneum associated with endometriosis. Interventions Laparoscopic excision and treatment of mesothelioma and endometriosis. Results Three patients underwent laparoscopy for treatment of endometriosis and were found to have peritoneal mesothelioma. All 3 patients underwent total laparoscopic excision of the lesions and were followed up regularly for surveillance of possible recurrence. Conclusions In selected cases of well-differentiated papillary mesothelioma associated with pelvic endometriosis, operative laparoscopy can be used effectively to diagnose and treat this condition.

Well-Differentiated Papillary Mesothelioma

Well-differentiated papillary mesothelioma is an unusual variant of epithelial mesothelioma considered to be of low malignant potential. The majority of previously reported cases developed in the peritoneum of young women without a history of asbestos exposure. The authors report 14 cases of well-differentiated papillary mesothelioma, seven of which originated in the pleura, six in the peritoneum, and one in the tunica vaginalis. Eleven of the patients were male and three were female, with an average age at presentation of 58 years (range 32-82 years). Six of the patients had a quantifiable history of asbestos exposure. Of the nine cases with complete follow-up, six had clinically indolent disease, one showed resolution after adjuvant chemotherapy, one pursued an aggressive course, and one died of other causes. These findings indicate that well-differentiated papillary mesothelioma is a rare variant of mesothelioma with a variable clinical prognosis that is etiologically related to asbestos exposure in some cases.

A Case of Well-differentiated Papillary Mesothelioma Developing Malignant Mesothelioma with Seeding Mass on the Trocar Insertion Site of Diagnostic Laparoscopy and Malignant Change.

Although well-differentiated papillary mesothelioma (WDPM) is usually classified as benign, the natural history of this lesion has not been clearly established. We present a case of WDPM in 60-year old woman developing malignant mesothelioma with seeding mass on the trocar insertion site over a period of 2 years. The initial symptom exhibited by the patient was abdominal distension from massive ascitic fluid. With an impression of peritoneal carcinomatosis, we performed a diagnostic laparoscopy. On the laparoscopic finding, a small whitish nodule was found on the liver surface and the pathologic result revealed reactive mesothelial hyperplasia. At exploro-laparotomy, multiple small nodules were found on the omentum and a biopsy revealed well-differentiated papillary mesothelioma of the peritoneum. The patient underwent pelvic lymphadenectomy and omentectomy of the colon and was followed for 2 years without any further treatment. Subsequently, she presented with abdominal distention with massive ascites and palpable abdominal wall mass at the previous trocar insertion site. Malignant mesothelioma was confirmed histologically via re- exploration. The rare transformation of well-differentiated papillary mesothelioma into a typically malignant diffuse mesothelioma and the unusual seeding on trocar insertion site prompted us to report this case.

Well-differentiated papillary mesothelioma of the peritoneum. A clinicopathologic study of 22 cases

Twenty-two cases of well-differentiated papillary mesothelioma of the peritoneum (WDPMP) are described. Eighteen of the 22 patients were women. The peritoneal tumor was usually multifocal. Many of the tumors appear to be indolent or inactive and for practical purposes are benign. However, a few patients receiving adjuvant therapy have died under circumstances that make it difficult to determine whether the tumor was responsible for the death. It is suggested that adjuvant therapy be withheld from patients with WDPMP, unless there is clear evidence of progression. The cause of these rare tumors is not apparent, although three patients had had possible exposure to asbestos and two were sisters.