Fatal ALK-negative systemic anaplastic large cell lymphoma presenting with disseminated cutaneous dome-shaped papules and nodules.

Anaplastic large cell lymphoma (ALCL) is classified as a CD30 positive non-Hodgkin lymphoma. Systemic ALCL (S-ALCL) is further subdivided into two subgroups based on anaplastic lymphoma kinase (ALK) expression. In systemic ALCL, positive ALK expression correlates with a favorable prognosis, whereas negative ALK expression correlates with poorer overall survival. By definition, primary cutaneous ALCL (cut-ALCL) is limited to the skin and is uniformly ALK-negative. Cut-ALCL closely resembles LyP with regards to its benign clinical course and CD30 positivity. We describe a unique case of ALK-negative (ALK-) S-ALCL presenting with cutaneous disseminated dome-shaped papules.