Cutaneous leiomyosarcoma: a retrospective review of 45 cases
Sabrina Khan, Ruth Asher, William Perkins, Rubeta N Matin- Dermatology
Abstract
Aims
Primary cutaneous leiomyosarcomas (LMS) are rare soft tissue tumours with two subtypes: dermal and subcutaneous. As deeper tumours confer a worse prognosis, they require a more aggressive approach. Conversely, a more conservative surgical approach for dermal LMS has been suggested. Few studies have comprehensively reported both clinical surgical and histological excision margins. We therefore sought to provide margin recommendations based on our experience and review of existing literature.
Methods
Retrospective case-note review (1998–2019) of cutaneous LMS management was undertaken to establish histological/surgical margins using pathology/electronic patient records. The diagnosis was made and classified according to the WHO classification by an experienced Dermatopathologist.
Results
Dermal LMS cohort (n = 35): mean peripheral and deep histological margins were 5.4 mm (range 0.5–20 mm) and 5.6 mm (range 0.1–14.5 mm), respectively. Incomplete excision rate: 31% (11/35). There were no recurrences. Subcutaneous LMS cohort (n = 10): mean peripheral and deep histological margins were 5.7 mm (range 0.2–14 mm) and 1.1 mm (range 0.2–1.7 mm), respectively. Incomplete excision rate: 40% (4/10). Recurrence rate: 20% (2/10) despite achieving histological clearance after 1 year. One lung metastasis occurred 1 year following an adequately excised primary scalp LMS.
Conclusions
We propose that for dermal LMS, a clinical margin of 5-10 mm (depending on size of lesion) at the initial excision or at scar re-excision following involved/close histological peripheral and/or deep margins (i.e. < 1 mm) is undertaken. For subcutaneous LMS, a clinical margin of 15-20 mm (depending on size of lesion) to achieve a peripheral histological clearance of 10 mm and negative deep margin (i.e. > 1 mm) down to periosteum/fascia/muscle according to anatomical site is suggested. If this is not achieved, a re-excision would be recommended. However, prospective studies are needed for optimal guidance.