CD68 positivity suggests histiocytic (monocytic) lesions, but also soft tissue granulosa cell tumors, melanotic tumors, and some carcinomas, and patients need to be examined promptly to clarify the cause. CD68 is a lysosomal protein. Monoclonal antibodies are available as KP-1 and PG-M1. KP-1 can label monocytes, macrophages and myeloid cells, while PG-M1 only labels monocytes and macrophages, not myeloid cells, and the commonly used antibody is KP-1. CD68 may be positive in histiocytic (monocytic) lesions such as juvenile yellow granuloma, xanthoma, fibrous xanthoma and histiocytic lymphoma. However, CD68 is not a specific marker for histiocytes, and certain cancers, such as soft tissue granulosa cell tumors, melanomatous tumors, and some cancers can also result in CD68 positivity. When the CD68 positive need to be timely examination, to clarify the specific lesions caused by the patient to ensure that enough rest after the examination, avoid excessive exertion to quit smoking and alcohol.