[Mohs micrographic surgery in two children with dermatofibrosarcoma protuberans]. / Chirurgie micrographique de Mohs dans le dermatofibrosarcome de Darier-Ferrand de l'enfant.

Dermatofibrosarcoma protuberans is a rare low-grade malignant tumor. The pseudopodia structure of the tumor requires 3-5 cm surgical margins. Mohs micrographic surgery (MMC) can reduce these margins to 1.3 cm while controlling all the histological excision margins. Children seem to be a good indication for this technique because it reduces the amount of skin removed. We report 2 cases of pediatric DFS treated with CMM to illustrate the usefulness of this technique in pediatrics. Two girls, aged 12 and 13 years, had a dermatofibrosarcoma located on the breast and sternum, respectively. CMM was proposed. One operative session was needed with direct closure in a second phase. MMS is a useful surgical technique for childhood tumors. If dermatofibrosarcoma is a very good indication in children, other skin tumors could benefit from this approach.

[Long-term efficacy of autologous stem cell transplantation for stage IV mycosis fungoides]. / Efficacité a long terme d'une autogreffe de cellules souches au cours d'un mycosis fongoïde de stade IV.

BACKGROUND: Mycosis fungoides during large cell transformation to lymphoma has a poor prognosis with mean survival of 36 months. Autologous stem cell transplantation is rarely proposed in this indication. We report the case of a young man still in complete remission for transformed mycosis fungoides 14 years after autologous stem cell transplantation. CASE REPORT: A 25-year-old man presenting eczema-like patches since childhood was treated by chemotherapy for multiple lymphadenopathies considered as Hodgkin's lymphoma. He was referred with diffuse skin tumours and infiltrated patches. Histology of tumour samples revealed atypical T-cell infiltrate with epidermotropism and presence of more than 25% of large CD30-positive cells. Non-infiltrated patches showed small T-cell lymphoma with epidermotropism. Histological verification of a previous lymphadenopathy confirmed the diagnosis of transformed mycosis fungoides. Despite multiple courses of chemotherapy, the disease progressed, with neurological involvement in particular. Because of tumour aggressiveness, autologous stem cell transplantation was performed and resulted in rapid regression of the tumours, lymphadenopathy and neurological symptoms. Non-transformed mycosis fungoides patches persisted but were controlled with topical mechlorethamine. This patient is still in complete remission for tumour and extracutaneous lesions 14 years after the autograft. DISCUSSION: This was probably a case of juvenile mycosis fungoides diagnosed and transformed in adult age. Neurological involvement by mycosis fungoides is rare and usually carries a drastic prognosis. To our knowledge, this is the longest remission of transformed mycosis fungoides seen after autograft. It highlights the value of this method in aggressive transformed mycosis fungoides, especially in patients ineligible for allograft.