MALIGNANT MESOTHELIOMA OF THE PERITONEAL CAVITY – EPIDEMIOLOGICAL,CLINICAL, DIAGNOSTIC, THERAPEUTIC AND PROGNOSTIC FEATURES. CASE REPORT –A DIFFERENTIAL DIAGNOSTIC CHALLENGE FROM OUR DAILY PRACTICE

Abstract

Malignant peritoneal mesothelioma (MPM) is a rare and clinically aggressive tumor originating from the serous surface of the abdominal cavity. Clinical manifestations include nonspecific symptoms. Several factors influence the prognosis of MPM patients, including age, gender, histological type, tumor grade, extent of disease and response to therapy. The treatment for MPM involves cytoreductive surgery combined with hyperthermic intraperitoneal chemotherapy. In some cases, systemic chemotherapy is also applied. However, treatment can be associated with significant complications, emphasizing the need for a multidisciplinary medical team to determine the most appropriate clinical approach. Pathologists face differential diagnostic challenges in distinguishing MPM from other conditions such as primary peritoneal serous carcinoma, reactive mesothelial proliferation, mesothelioma in situ, benign mesothelial inclusions and metastatic tumors. Histological features, along with immunohistochemistry markers, matched with clinical and imaging data, aid in making accurate diagnosis. In order to illustrate the application of this complex diagnostic approach, we present a case of a 29-year-old man. We initially diagnosed him with benign mesothelial inclusions in a cervical lymph node, which were considered a post COVID-19 infection complication. A few weeks later, after analyzing the data from new imaging test, we recommended obtaining a biopsy sample from the abdominal cavity and diagnosed him with malignant epithelioid mesothelioma.