Ki-1-positive large-cell cutaneous lymphoma mimicking a Stewart-Treves angiosarcoma

Anaplastic large-cell cutaneous lymphomas (ALCL) represent a heterogeneous group. Primitive cutaneous lymphomas are exceptional, sometimes with a deceptive clinical aspect, but must be considered as a distinct clinicopathologic entity. We report a case of a cutaneous ALCL, appearing 7 years after a homolateral Hodgkin ganglionic lymphoma and occurring on a chronic lymphoedema of the arm. A Stewart-Treves angiosarcoma was suggested owing to its location, vascular aspect and low histologic differentiation. Immunohistochemistry was helpful in making the diagnosis of ALCL. Southern blotting analysis revealed a rearrangement of the beta-chain of the T-receptor gene, thus suggesting the T-cell origin of this lymphoma.