PDPN and malignant mesothelioma: By contrast, podoplanin expression has been reported in many cancers, including squamous cell carcinomas (head and neck, lung, and esophageal carcinomas), malignant brain tumors, malignant mesotheliomas, bladder cancers, and testicular tumors1, 9, 10, 11, 12, 13, 14, 15, 16, 17.