A case report of a 2-year-old boy, admitted to the hospital with a solitary benign fibrous mesothelioma (BFM) in the abdomen, was recently published in the Asian Journal of Surgery.
The report, “Solitary benign fibrous mesothelioma of the peritoneum: A rare entity in a 2-year-old child,“ by Sunita Singh and colleagues from the Pandit Bhagwat Dayal Sharma Post Graduate Institute of Medical Sciences, India, describes an extremely unusual event.
BFM usually develops in men with a mean age of 54. Apart from the age of the patient, the location of the tumor was also uncommon in the child. BFM most often develops from cells lining the pleural cavity – the bodily space holding the lungs. BFM tumors arising in other locations in the thoracic cavity are called extrapleural fibrous tumors and affect only 2.8 of 100,000 individuals.
While malignant mesothelioma is associated with asbestos exposure, researchers are still in the dark about the cause of more benign types of the tumors arising in the mesothelium. Benign tumors can often be removed surgically, but they might reoccur, therefore patients with benign tumors need to be closely monitored.
A visual examination cannot easily distinguish between malignant and benign mesothelioma tumors, and since the tumor present in the child was found in such a rare place – close to the pelvis – the doctors had to consider several different diagnoses.
The team examined the tumor with ultrasound and computed tomography (CT) scans before surgically removing it. Tissue from the tumor was then analyzed using antibody staining specific for a range of different tumors.
The child’s tumor was found to be positive for antibodies directed at CD34 and vimentin, but did not stain with antibodies directed at CD117, SMA, S100, and CD99. This profile allowed the team to exclude the possibility that the tumor was either a gastrointestinal stromal tumor, a mesenteric fibromatosis, or a myofibroblastic tumor, finally arriving at the BFM diagnosis.
Reports of child mesothelioma mention a handful of cases since the 1950s. Earlier theories of child mesothelioma mentioned secondary asbestos exposure from exposed family members as a potential cause, but a report from 1989 concluded that is an unlikely cause of child mesothelioma. Since the cases are so rare, it is difficult to investigate the reasons for mesothelioma development in children.