Metastasis of malignant peritoneal epithelioid mesothelioma in endoscopic gastric biopsy: a diagnostic pitfall.
OBJECTIVE
To describe a case of metastasis of malignant peritoneal epithelioid mesothelioma in gastric antral mucosa in a patient with a cryptogenic liver cirrhosis associated with esophageal varices, abdominal pain and distension, ascites, and weight loss.


METHODS
The patient underwent esophageal gastric endoscopy for varices, and a biopsy of a polypoid antral lesion was performed. The latter revealed a proliferation of polygonal cells with moderately atypical nuclei and pale eosinophilic, peripherally condensed cytoplasm infiltrating into the lamina propria between the normal mucosal glands of the antrum. The tumor cells were diffusely positive to anticalretinin antibody, whereas anti-claudin 4 and anti-CEA antisera were negative.


CONCLUSIONS
Metastases of malignant peritoneal mesotheliomas are unusual, and a predominantly gastrointestinal localization is rare. Pathologists should be aware of this possibility to avoid misdiagnosis, particularly in small biopsy specimens.
Daniele
Lorenzo
L
Department of Biomedical Sciences and Human Oncology, University of Turin, Turin, Italy.
Righi
Alberto
A
Ferraris
Andrea
A
Macrì
Luigia
L
Asioli
Sofia
S
D001706:Biopsy; D006801:Humans; D008654:Mesothelioma; D010534:Peritoneal Neoplasms; D010537:Peritoneum; D013270:Stomach