Primary cutaneous anaplastic large cell lymphoma with angioinvasive features and cytotoxic phenotype: a rare lymphoma variant within the spectrum of CD30+ lymphoproliferative disorders.

Background: Primary cutaneous anaplastic large cell lymphoma (PCALCL) presents with solitary or grouped exophytic tumors and cohesive infiltrates of large CD30+ T cells.

Objective: To report an angioinvasive variant of PCALCL.

Methods: Retrospective analysis of clinicopathological features of this variant.

Results: The group consisted of six patients (median age 46 years) with a solitary flat necrotic lesion preferentially located on the upper extremity. Histologically, there were angiocentric and angiodestructive infiltrates of medium-sized to large pleomorphic and anaplastic cells co-expressing CD30 and CD8. Five patients were treated with surgical excision and one patient with radiotherapy. A relapse was observed in one patient with spontaneous regression of the lesions suggesting a link to the recently described angioinvasive lymphomatoid papulosis (type E). All patients were alive without evidence of disease after a median follow-up of 31 months (range 15-96), indicating an excellent prognosis.

Conclusions: The angioinvasive variant of PCALCL is rare but distinctive and prone to misinterpretation as aggressive lymphoma due to its histological features.