An Isolated Cutaneous Relapse in a Known Case of Systemic ALK-Positive Anaplastic Large Cell Lymphoma: A Rare Case Report with Review of Literature

Abstract Among non-Hodgkin's lymphomas (NHLs), anaplastic lymphoma kinase (ALK)-positive anaplastic large cell lymphoma (ALCL) is a relatively uncommon subtype that accounts for 3% of all adult NHLs. It typically affects young males, with a prevalence of three to one. Most cases present with nodal disease at the time of presentation. An extranodal involvement is seen in 60% of cases and skin involvement is seen in only 8 to 21% of cases. Cutaneous involvement in ALCL can manifest as primary cutaneous ALCL or secondary to systemic ALCL, and while CD30 positivity is common to both, ALK is not expressed by the former. A secondary skin involvement is usually associated with a poorer prognosis. We report a rare case of an isolated cutaneous relapse of systemic ALK-positive ALCL in a 62-year-old woman following the second cycle of chemotherapy. The acute febrile, widespread papulonodular eruption clinically resembled mycosis fungoides and lymphomatoid papulosis. With the introduction of oral crizotinib, a drastic improvement in the skin lesions and an exceptional response on positron emission tomography-computed tomography were noted.