Diagnosis of mucinous tumors typically involves a combination of imaging studies, histopathological examination, and sometimes, molecular testing. Imaging techniques such as ultrasound, CT scans, and MRI can help identify the presence of a mucinous mass. Histopathology, which involves examining tissue samples under a microscope, is crucial for confirming the diagnosis. Special stains and immunohistochemistry may be used to differentiate mucinous tumors from other types of neoplasms.