[Cutaneous and subcutaneous primary leiomyosarcoma: A retrospective cohort of 26 cases examining clinical data and treatments].

Background: Superficial leiomyosarcoma is a rare malignant soft tissue tumor arising from smooth muscle cells, accounting for 2-3% of superficial sarcomas, with limited literature available on the subject. It is typically observed in patients aged 50-60 years and affects both men and women equally in the subcutaneous subtype, whereas the cutaneous subtype predominantly affects men.

Objective: This study aims to examine the clinicopathological features and therapeutic outcomes of patients with leiomyosarcoma.

Method: This is a descriptive retrospective study of 26 cases of cutaneous and subcutaneous leiomyosarcomas, with histological confirmation.

Results: We identified 10 (38.5%) subcutaneous leiomyosarcomas and 16 (61.5%) cutaneous leiomyosarcomas. The majority of tumors were located in the lower limbs, accounting for 13 (50%) cases. During follow-up, 6 patients experienced recurrence, and 7 developed metastases, including 2 of the 7 patients who had R0 resection margins. Among these, 3 out of the 6 recurrent cases and 3 out of the 7 metastatic cases were subcutaneous leiomyosarcomas. The average time to recurrence was 6.2 years.

Conclusion: The observed risk of metastases and recurrences, despite clear surgical margins, in both cutaneous and subcutaneous leiomyosarcomas, along with the delayed onset of these events, justifies prolonged patient follow-up. The lungs, bones and liver have been identified as the most common site of metastasis.