Peritoneal Malignant Psammomatous Mesothelioma

Area of Science:

• Oncology
• Pathology

Background:

• Psammoma bodies (PBs) are calcified structures commonly found in papillary thyroid carcinoma, meningioma, and ovarian papillary serous cystadenocarcinoma.
• Peritoneal malignant mesothelioma (PMM) is a rare tumor arising from the peritoneum.

Observation:

• A 72-year-old male presented with abdominal swelling and weight loss.
• Imaging revealed diffuse peritoneal fluid, thickened omentum with micronodules, and peritoneal enhancement.
• Laparoscopy showed diffuse peritoneal nodules, and biopsy confirmed malignant epithelial-like cells with submesothelial involvement and massive psammoma body deposition.

Findings:

• Neoplastic cells exhibited positive calretinin, D2-40, and cytokeratin 5 staining.
• The patient received chemotherapy with gemcitabine, vinorelbine, and cisplatin.
• The presence of massive psammoma bodies in PMM is a rare finding.

Implications:

• Massive psammoma bodies might signify an active biological process, potentially leading to tumor cell death and growth retardation.
• Psammomatous malignant mesothelioma can mimic serous psammocarcinoma of the peritoneum.
• Further research is needed to determine if this finding defines a new PMM variant with a better prognosis.