Well-differentiated Papillary Mesothelioma Research Articles

Fine Needle Aspiration Cytologic Features of Well-Differentiated Papillary Mesothelioma in the Pleura - A Case Report -

Well-differentiated papillary mesothelioma (WDPM) is a rare subtype of malignant mesothelioma, which is considered to have low malignant potential. Because of its rare occurrence in the pleura, cytopathologists are not familiar with the cytologic features of WDPM, and to date only one report regarding the cytomorphology of aspiration biopsies of WDPM in pleura has been released. The authors present the findings of fine needle aspiration cytology of WDPM in the pleura in a 53-year-old woman. Aspiration smears showed papillary clusters composed of one to three layers of surface tumor cells and a central hyalinized stromal core. Tumor cells were round, ovoid, and spindle like with minimally atypical nuclei and small conspicuous nucleoli. Mitotic activity was virtually absent. Excisional biopsy histologic and immunohistochemical findings were wholly compatible with WDPM findings. Knowledge of the specific cytologic findings of WDPM is crucial for accurate diagnosis and appropriate treatment.

Peritoneal Mesotheliomas: Clinicopathologic Features, CT Findings, and Differential Diagnosis

The objective of our study was to illustrate various CT findings of peritoneal mesotheliomas, to review their clinicopathologic features, and to discuss the differential diagnoses. The clinicopathologic features of peritoneal mesotheliomas vary among the subtypes such as malignant mesotheliomas, cystic mesotheliomas, and well-differentiated papillary mesotheliomas, and accordingly, there is a spectrum of CT appearances.

Cytomorphologic features of well‐differentiated papillary mesothelioma in peritoneal effusion: A case report

Well-differentiated papillary mesothelioma (WDPM), a distinct subtype of diffuse malignant mesothelioma, usually occurs in the peritoneum and is seen most commonly in women of reproductive age. Histologic features of WDPM include papillary growth and stout fibrous cores surrounded by a single layer of tumor cells. We present the case of a 73-year-old woman without subjective symptoms who showed signs of peritoneal effusion during a routine examination and for whom cytologic examination of the ascitic fluid was performed. Many spherical clusters, with a smooth external surface composed of a single layer of uniform cuboidal cells, were observed. Within each cluster, a collagenous ball showed light green Papanicolaou staining. Immunohistochemistry of surgical specimens showed tumor cells positive for calretinin, D(2)-40, and HBME-1 staining. The histologic diagnosis was WDPM. The identification of a collagenous ball within these clusters is a useful cytologic finding for the diagnosis of WDPM. WDPM should be suspected when numerous collagenous balls are present by effusion cytology and isolated cells are not.

Unusual Multifocal Glomeruloid Pattern in a Well-Differentiated Papillary Mesothelioma of the Peritoneum

by clefted spaces. The mesothelial origin of the tumor was confirmed by immunoreactivity showing positive immunolabeling for calretinin (1:300; Dako, Carpinteria, California), CK 5/6 (1:30; Bio Sb, Santa Barbara, California), thrombomodulin (1:50; Dako), WT-1 (1:50; Cell Marque, Austin, Texas), and CK7 (1:100; Cell Marque). CK20 (1:50; Cell Marque) was negative (Figure 2). Well-differentiated papillary mesothelioma is an uncommon distinct subtype of mesothelioma that occurs principally in the peritoneum of women in the third and fourth decades. It is often discovered incidentally during abdominal or pelvic surgery, and it is generally regarded as a tumor of low malignant potential. In the English literature, less than 100 cases have been reported affecting both men and women, including cases arising in the pleura and tunica vaginalis. Histologically, WDPM is A46-year-old woman presented to the ABC Medical Center in Mexico City with the clinical picture of acute cholecystitis and underwent cholecystectomy. The patient had no history with regard of asbestos exposure. During surgery, incidental multifocal small firm, white to tan peritoneal nodules were found, ranging from 5 mm to 1 cm, and on frozen section, a diagnosis of papillary epithelial neoplasm consistent with well-differentiated papillary mesothelioma (WDPM) was rendered (Figure 1A). The patient underwent total hysterectomy, along with omentectomy and resection of multiple peritoneal and diaphragmatic implants. The serosal membranes of the uterus and ovary were unremarkable, although a microscopic focus (1 mm) of parenchymal infiltration was found in the left ovary. The histological study disclosed a well-developed tubulopapillary growth pattern with solid areas. The papillae were lined by a single layer of uniform cuboidal to flattened cells with minimal cytological atypia, covering thin fibrovascular cores. Mitosis was absent. The stroma showed focal myxoid change. Focal psammoma bodies were present. Throughout the tumor, constituting approximately 20% of the neoplasm and mainly localized to the periphery of the nodules, the fibrovascular papillae were arranged forming a distinct glomeruloid pattern of growth characterized by round to oval neoplastic mesothelial cell tufts supported by a fibrovascular core (Figures 1B and 1C). The mesothelial cells were sometimes arranged in semicircular concentric rows separated

Well-Differentiated Papillary Mesothelioma of the Tunica Vaginalis Testis

An 18-year-old man presented with a growing painless left scrotal mass. Sonography showed a hydrocele and a homogeneous, well-encapsulated left extratesticular mass with similar echogenicity as the normal testis, suggestive of a splenogonadal fusion. To substantiate the diagnosis, the patient underwent Tc-99m heat-denatured red blood cell scintigraphy showing normal physiological hyperactivity in the spleen but activity similar to the blood pool projecting on the upper part of the left testis. This made testicular splenic tissue less likely. The patient underwent resection and histopathology revealed a well-differentiated papillary mesothelioma. Inguinal orchidectomy was subsequently performed and the patient was free of recurrence at 18 months.

Multicystic and Well-differentiated Papillary Peritoneal Mesothelioma Treated by Surgical Cytoreduction and Hyperthermic Intra-peritoneal Chemotherapy (HIPEC)

Multicystic peritoneal mesothelioma (MPM) and well-differentiated papillary peritoneal mesothelioma (WDPPM) are exceedingly uncommon lesions with uncertain malignant potential and no uniform treatment strategy. The aim of the current study was to review our experience with cytoreduction and hyperthermic intraperitoneal chemotherapy (HIPEC) in these clinical settings. Four women with MPM and eight with WDPPM underwent 13 procedures of cytoreduction and close-abdomen HIPEC with cis-platin and doxorubicin. Seven patients had recurrent disease after previous debulking (one operation in five patients, two in one, four in one). Potential clinicopathological prognostic factors were assessed. Optimal cytoreduction (residual tumor nodules <or=2.5 mm) was performed in 12 of 13 procedures. Median follow-up was 27 months (range 6-94). One grade 4 postoperative complication (NCI/CTCAE v.3.0) and no operative mortalities occurred. One patient underwent the procedure twice due to locoregional MPM recurrence. Transition of typical WDPPM to malignant biphasic mesothelioma was documented in one patient who died of disease progression following incomplete cytoreduction and HIPEC. Following multimodality treatment, 5-year overall and progression-free survival were 90.0% (standard error = 9.0) and 79.7% (11.9), respectively. Progression-free survival following previous debulking surgery (median 24 months; range 2-87) was statistically worse (P = .0156). Incomplete cytoreduction and poor performance status correlated to both reduced overall and progression-free survival after cytoreduction and HIPEC. MPM and WDPPM are borderline tumors capable of transformation into potentially lethal processes. Definitive tumor eradication by means of cytoreduction and HIPEC seems more effective than debulking surgery in preventing disease recurrence or transition to aggressive malignancies.

Well-differentiated papillary mesothelioma: report of a case

患者女,41岁.因腹胀伴腹部隐痛5年余于2005年5月入院.体检:一般情况良好,追问病史患者以往曾有10年与职业相关的石棉接触史.入院后行腹腔镜检查时发现在子宫、双附件、回肠、阑尾、直肠等器官和肠系膜及盆腔底部腹膜表面有多发性散在分布的灰白色半透明结节,0.2～1.5cm大小.另见盆腔内有少量积液,于术中分别取盆底、右输卵管及肠系膜病变组织,同时抽取腹水20 ml送检。

Well-differentiated papillary mesothelioma occurring in the tunica vaginalis of the testis with contralateral atypical mesothelial hyperplasia

Well-differentiated papillary mesothelioma (WDPM) occurs rarely in the paratesticular region, with only a handful of published case reports. Often presenting with recurrent hydrocele, WDPM is a multifocal mesothelial proliferation with a predominantly indolent clinical course. Accordingly, pathologic distinction of this lesion from true malignant mesothelioma is crucial, although it may be difficult because of the variability of associated histologic features. In addition, rare cases of WDPM have progressed to malignant mesothelioma, leading to its classification as a tumor of low malignant potential. Here, we report a case of multifocal WDPM occurring in the tunica vaginalis and tunica albuginea, with contralateral atypical mesothelial hyperplasia, a potentially premalignant lesion.

Well-differentiated Papillary Mesothelioma of the Peritoneum: A Pathological Analysis and Review of the Literature

Well-differentiated Papillary Mesothelioma of the Peritoneum: A Pathological Analysis and Review of the Literature

Value of estrogen and progesterone receptor immunostaining in distinguishing between peritoneal mesotheliomas and serous carcinomas

The differential diagnosis between peritoneal mesotheliomas and serous carcinomas involving the peritoneum may be difficult, but it can be facilitated by the use of immunohistochemistry. To determine whether estrogen receptors (ER) or progesterone receptors (PR) may have any value as immunohistochemical markers for discriminating between these malignancies, 40 serous carcinomas of the ovary metastatic to the peritoneum, 7 primary peritoneal serous carcinomas, 30 epithelioid peritoneal malignant mesotheliomas, 5 well-differentiated papillary mesotheliomas, and 4 adenomatoid tumors were immunostained for ER and PR. Reactivity for ER was obtained in 35 (88%) of the metastatic serous carcinomas of the ovary and 6 (86%) of the primary peritoneal serous carcinomas, whereas positivity for PR was observed in 24 (60%) of the metastatic serous carcinomas and 4 (56%) of the primary peritoneal serous carcinomas. None of the mesotheliomas or adenomatoid tumors expressed ER or PR. It is concluded that, because of its high sensitivity for serous carcinomas, ER immunostaining could be very useful in distinguishing between serous carcinomas and peritoneal mesotheliomas. Immunostaining for PR, however, has little practical utility.

Well-differentiated papillary mesothelioma of the peritoneum: A pathological analysis and review of the literature

Background Well-differentiated papillary mesothelioma (WDPM) of the peritoneum is a rare subtype of peritoneal epithelioid mesothelioma which typically has low malignant potential. It most commonly occurs in young women lacking a history of asbestos exposure. Only 38 female patients with peritoneal WPDM have been reported in the literature, and no uniform treatment recommendation has been established. Case report A 74-year-old asymptomatic woman without significant past medical history underwent workup and subsequent surgery for an adnexal mass with a normal serum CA-125 level. Exploratory laparotomy identified an ovarian serous cystadenoma and an incidental multifocal peritoneal neoplasm with extensive calcifications. Histology and cytology confirmed WDPM with extensive, intimately associated mesothelial cystic inclusions and zonal calcifications with osseous metaplasia. Our patient did not receive adjuvant therapy and was without clinical or radiologic evidence of disease 12 months after diagnosis. Conclusion WDPM of the peritoneum in women is frequently asymptomatic and associated with an indolent course. Patient outcomes are usually favorable after tumor-debulking surgery without adjuvant therapy.

Malignant Peritoneal Mesothelioma in Women: A Study of 75 Cases With Emphasis on Their Morphologic Spectrum and Differential Diagnosis

Seventy-five malignant mesotheliomas of the peritoneum in women were reviewed to highlight their morphologic spectrum. The patients ranged from 17 to 92 (mean, 47.4) years of age. The clinical presentation was usually abdominal or pelvic pain, abdominal swelling (sometimes due to ascites), or a pelvic mass. On microscopic examination, the majority of the tumors had only an epithelial morphology, but 4 were biphasic and 1 was sarcomatoid. The most common epithelial patterns were tubular and papillary (which often coexisted), but 5 tumors were purely diffuse; 2 had cells with abundant glassy eosinophilic cytoplasm (so-called deciduoid mesothelioma). The cells in the tubular and papillary patterns were generally cuboidal with scant to moderate amounts of eosinophilic cytoplasm. Nuclear atypia was usually only mild, although a minority of cases had moderate or even, occasionally, severe atypia. Many tumors had foci that, viewed in isolation, resembled so-called well-differentiated papillary mesothelioma, and accordingly that diagnosis should be made cautiously. Unusual features were lymphoid follicles (13 cases), striking myxoid stroma (5 cases), prominent foamy histiocytes (5 cases), and a striking vascular proliferation (1 case). The varied morphology of peritoneal malignant mesotheliomas may raise a broad differential diagnosis, but in most cases the resemblance to other tumors is limited. Histochemistry, immunohistochemistry, and electron microscopy may provide important aid, particularly when tissue is limited, but should be needed only occasionally.

Malignant Peritoneal Mesothelioma in Women

Seventy-five malignant mesotheliomas of the peritoneum in women were reviewed to highlight their morphologic spectrum. The patients ranged from 17 to 92 (mean, 47.4) years of age. The clinical presentation was usually abdominal or pelvic pain, abdominal swelling (sometimes due to ascites), or a pelvic mass. On microscopic examination, the majority of the tumors had only an epithelial morphology, but 4 were biphasic and 1 was sarcomatoid. The most common epithelial patterns were tubular and papillary (which often coexisted), but 5 tumors were purely diffuse; 2 had cells with abundant glassy eosinophilic cytoplasm (so-called deciduoid mesothelioma). The cells in the tubular and papillary patterns were generally cuboidal with scant to moderate amounts of eosinophilic cytoplasm. Nuclear atypia was usually only mild, although a minority of cases had moderate or even, occasionally, severe atypia. Many tumors had foci that, viewed in isolation, resembled so-called well-differentiated papillary mesothelioma, and accordingly that diagnosis should be made cautiously. Unusual features were lymphoid follicles (13 cases), striking myxoid stroma (5 cases), prominent foamy histiocytes (5 cases), and a striking vascular proliferation (1 case). The varied morphology of peritoneal malignant mesotheliomas may raise a broad differential diagnosis, but in most cases the resemblance to other tumors is limited. Histochemistry, immunohistochemistry, and electron microscopy may provide important aid, particularly when tissue is limited, but should be needed only occasionally.

Well-differentiated papillary mesothelioma of the pleura: a series of 24 cases.

Well-differentiated papillary mesothelioma (WDPM) of the pleura represents a distinct mesothelial tumor presenting with unilateral pleural effusion and superficial spreading of stout papillary formations with myxoid cores, lined by bland, flattened, or epithelioid cells, without or with limited invasion of the submesothelial layer. The majority of cases have been reported in the peritoneum in women of reproductive age with no history of asbestos exposure and also in the tunica vaginalis of men. We report 24 cases of pleural WDPM and compared their histologic, epidemiologic, and clinical features with those of classic mesothelioma. Men and women were equally affected, with a mean age of 60 years. Half of the patients had a history of occupational asbestos exposure. In 11 patients with a minimal follow-up period of 24 months, the survival ranged from 36 to 180 months with an average of 74 months as compared with 9.89 months for 1248 paired patients with diffuse malignant mesothelioma. Ten-year survival was 30.8%. We conclude that WDPM is a rare and unusual mesothelial tumor, characterized by a lack of deep invasion and associated with an indolent clinical course and long survival. For these reasons, WDPM is best considered as a specific clinico-pathologic entity distinct from conventional diffuse malignant mesothelioma.

Paratesticular mesothelial proliferations

Varied mesothelial proliferations are found around the testes. Benign reactive mesothelial proliferations in hydrocoeles may be very florid and histologically worrisome, but these can usually be separated from malignant mesotheliomas of the tunica vaginalis because they are confined to a sharply demarcated zone near the luminal surface. In addition, benign inflamed hydrocoeles tend to show a distinct zonation with cellular areas near the luminal surface and more fibrotic areas beneath. The proliferating mesothelial cells in benign reactions often form lines that are parallel to the surface of the hydrocoele. Malignant mesotheliomas of the tunica vaginalis are usually grossly visible as single or multiple nodules. Histologically, they show an epithelial- or mixed epithelial- and sarcomatous-morphologic image, with evidence of stromal invasion. Well-differentiated papillary mesotheliomas are usually solitary exophytic nodules with a distinctive morphologic appearance and benign course, but they must be carefully separated from malignant mesotheliomas with a focally exophytic papillary growth pattern. By definition, well-differentiated papillary mesotheliomas do not exhibit stromal invasion. Peritesticular adenomatoid tumors are also very common; they are benign circumscribed cellular nodules with an appearance comparable to that of adenomatoid tumors in other body locations such as the uterine serosa.

Peritoneal mesothelioma treated by induction chemotherapy, cytoreductive surgery, and intraperitoneal hyperthermic perfusion

Peritoneal mesothelioma (PM) is a rare disease, with a poor prognosis. We decided to prospectively evaluate the prognostic impact of aggressive surgery followed by intraperitoneal chemotherapy with local hyperthermia. In this prospective study, 19 patients with PM were treated by cytoreductive surgery (CRS) and intraperitoneal hyperthermic perfusion (IPHP). Mean follow-up was 27 months (range: 1-65). Fifteen (68%) patients had malignant disease, two had well-differentiated papillary mesothelioma, and two had multicystic PM. Thirteen (65%) patients received preoperative chemotherapy. Fifteen cases (75%) underwent optimal cytoreduction (residual disease <2.5 mm). One patient underwent the procedure twice due to locoregional progression. IPHP was performed with closed abdomen technique, using a preheated polysaline perfusate (42.5 degrees C) containing cisplatin + mitomycin C or cisplatin + doxorubicin administered through a heart-lung pump for 60 or 90 min. Three-year overall and progression-free survival was 69 and 66%, respectively. The operative morbidity (grade II/III), mortality, and overall toxicity (grade I-IV) rates were 25, 0, and 30%, respectively. Seventeen (94%) out of 18 patients had resolution of ascites. This therapeutic strategy proved feasible and was well tolerated. Early results seem promising and consistent with a potentially major impact on survival in selected patients with PM.

Laparoscopic Diagnosis and Treatment of a Well-Differentiated Papillary Mesothelioma of the Peritoneum

Well-differentiated papillary mesothelioma is a rare neoplasm of peritoneum, found mainly in women of reproductive age, and usually misdiagnosed as an ovarian mass. A 46-year-old woman was clinically suspected of having an adnexal mass. Peritoneal mesothelioma was diagnosed and successfully removed at laparoscopy. Laparoscopy allows differentiation from ovarian serous tumors and treatment of the lesions. Long follow-up is recommended because of the tendency to recur.

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.

Benign papillary mesothelioma of the tunica vaginalis testis.

We report a case of benign mesothelioma of the tunica vaginalis testis in a 69-year-old man who presented with a 4-month history of scrotal swelling. A polypoid pedunculated nodule, 1.5 cm in diameter, was found near the head of the right epididymis. Histologically, the tumor exhibited features characteristic of a well-differentiated papillary mesothelioma. The mesothelial origin of this tumor was further supported by immunohistochemical analysis. The tumor cells exhibited nuclear p53 protein accumulation, despite the benign histologic findings and a 3-year uneventful follow-up after resection. A polymerase chain reaction analysis for simian virus 40 DNA was negative. The papillary configuration seen in this tumor is uncommon for this site, inasmuch as benign mesotheliomas of the tunica vaginalis testis usually exhibit an adenomatous pattern. One should be aware of this pattern, and benignity should be mentioned in the pathologic report to prevent overtreatment. In addition, positive p53 immunohistochemical staining should not be taken automatically as evidence for malignancy in this type of lesion.