A case of anaplastic lymphoma kinase-positive anaplastic large cell lymphoma presenting with spontaneous splenic rupture: an extremely unusual presentation.

In a 22-year-old male with a 10-day history of fever, painful swelling in the left groin, and abdominal complaints, emergency surgery was performed because of spontaneous splenic rupture. At histology, a cellular infiltrate of intermediate-sized atypical lymphocytes was seen in the splenic white pulp, staining for T-cell markers. In addition, CD30 and anaplastic lymphoma kinase 1 (ALK) were diffusely positive, thus, representing a case of anaplastic large cell lymphoma (ALCL), T-cell, ALK-positive, small cell monomorphic variant. ALK-positive ALCL patients generally bear a much better prognosis than patients with T-cell lymphomas, unspecified, or ALK-negative ALCL. Therefore, besides the very unusual clinical presentation, this case highlights the importance of immunostaining for CD30 and ALK in all T-cell lymphomas. This report is the first extensive description of ALK-positive ALCL involvement of the spleen.