Well-differentiated papillary mesothelioma: peritoneal implants are not always metastases in the presence of cancer

Abstract

We highlight the need for a high index of suspicion, biopsies at staging laparoscopy and undertake a review of the literature regarding this uncommon condition.

Well-Differentiated Papillary Mesothelioma with Omental Calcifications: A Case Report and Review of the Literature

“…PAX8 has also been shown to be less useful in differentiating WDPM from serous papillary carcinoma due to crossover of the immunophenotypic patterns of PAX8 [5]. However, the presence of calretinin, as in our case, is much more likely in WDPM [4][5][6][7][8][9][10][11][12][13][14][15][16]18] and occurs in a smaller percentage of cases of serous papillary carcinoma [5,23] (Table 2). Interestingly, the calcification in our case was positive for ER, which occurs commonly in serous papillary carcinoma but generally not in WDPM [23,33].…”

“…The well-formed papillary architecture of WDPM superficially spreads and is lined by single layers of bland, cuboidal, or flattened mesothelial cells with little to no nuclear atypia, usually without mitoses [5,38]. In some instances of WDPM, psammomatous bodies [8,11,15,16,20,21] and invasive foci [5,6] have been reported. In a recent study of 75 patients with WDPM [5], the affected areas/nodules were generally less than 2 cm in diameter but ranged from 6 mm to 6.0 cm in diameter.…”