Unusual presentation of chondroid syringoma of the hand: a literature review and case report

Introduction and importance: Malignant chondroid syringoma (CS) is a sporadic skin tumor with slow growth and metastatic potential. Its presentation in the hand is uncommon, and limited cases have been reported in the literature. This case highlights an unusual presentation of malignant CS with delayed diagnosis, bone erosion, and distant metastases, adding to the sparse surgical literature on this tumor's aggressive behavior. Case presentation: A 67-year-old male with a 5-year history of a progressively enlarging ulcerative lesion on his left hand, initially mistaken for an insect bite. The lesion caused pain, limited finger mobility, and led to fifth-digit loss. Imaging revealed soft tissue swelling, bone erosion, and multiple lytic lesions in bone. The patient underwent a ray amputation of the ring finger. Pathology confirmed malignant CS with positive S-100 and CA-9/19 markers. Despite chemotherapy and surveillance, the patient's condition worsened due to metastatic progression, resulting in death 2 years after the initial presentation. Clinical discussion: Malignant CS of the hand is a rare tumor with sparse literature on its aggressive behavior. It may be easily misdiagnosed as a benign chronic lesion, leading to delayed treatment. Early recognition with aggressive evaluation could allow for timely wide excision with appropriate margins and surveillance, limiting metastasis and poor prognosis. Conclusion: This case emphasizes the importance of considering malignant CS in chronic hand lesions with progressive bone involvement. Early diagnosis, wide local excision, and close monitoring are crucial due to the tumor's metastatic potential and poor prognosis, especially in larger or truncal tumors.