Typical Mesothelioma, Diagnostic of Mesothelioma

Detecting characteristic ultrastructural features by electron microscopy may help the diagnosis of malignant mesothelioma.

Typical mesothelioma show tall and thin microvilli on the cell surface. It has been suggested that only microvilli whose length exceeds the width by a margin of 15:1 are diagnostic of mesothelioma.[35] Because the microvilli are often poorly developed in the sarcomatoid variety, electron microscopy is generally not useful in their diagnosis.

Peritoneal mesothelioma usually remains confined to the peritoneal cavity for most of its natural history. Typical growth pattern of peritoneal mesothelioma is locally expansive masses.
 Hematogenous or lymphatic metastasis is unusual. However, parasternal,[37] retroperitoneal,[38] mediastinal,[39,40] axillary, supraclavicular,[41] and cervical[40] lymph nodes; lung,[42] bone,[41,43] liver,[40] and umbilical ('Sister Mary Joseph's nodule')[44] metastases have all been reported.

   
Treatment
For patients with confirmed MPM, radical resection is associated with better prognoses and should be pursued when possible. Other treatments for peritoneal mesothelioma include intensive loco-regional therapeutic strategies: cytoreductive surgery, hyperthermic intraoperative or early postoperative intraperitoneal chemotherapy, and immunotherapy.

Surgery can achieve a complete or incomplete resection. The aim of cytoreductive surgery is to remove as much tumor as possible, as it is often not possible to achieve a complete resection. After surgical debulking, the resection can be classified according to the Completeness of Cytoreduction Score,[45]
which evaluates the residual peritoneal seeding within the operative field: complete (CC-0) or partial with a diameter of the residual nodules < 0.25 cm (CC-1), 0.25-2.5 cm (CC-2), > 2.5 cm or confluence of tumor nodules (CC-3). The CC-1 tumor nodule size is thought to be penetrable by intracavitary chemotherapy and is, therefore, designated as complete cytoreduction if perioperative intraperitoneal chemotherapy is used. The limitation of this score is the fact that it can be evaluated only after surgery; therefore, no preoperative informations can be obtained about the resectability of the tumor