Autoimmune lymphoproliferative syndrome: a syndrome associated with inherited genetic defects that impair lymphocytic apoptosis--CT and US features.

PURPOSE: To describe the imaging findings in patients with autoimmune lymphoproliferative syndrome (ALPS) and to relate the findings to the clinical and genetic features of this recently recognized syndrome.
MATERIALS AND METHODS: Retrospective or prospective reviews of the computed tomographic (CT) and ultrasonographic (US) studies and the clinical features in 19 consecutive patients with ALPS were performed.
RESULTS: Most patients presented in the 1st year of life with symptoms of adenopathy and hepatosplenomegaly. At the time of presentation to the institution, 12 patients had already undergone splenectomy, and 14 patients had developed autoimmune disorders. All patients had multifocal adenopathy, which was massive in some patients; 14 of 15 patients who underwent CT of the chest had an enlarged thymus, and all six patients who retained their spleens and who underwent imaging had splenomegaly. Ten of 18 patients who underwent liver imaging had hepatomegaly. The adenopathy at US was hyper- and/or isoechoic relative to the liver and thyroid and was enhanced at CT in some patients. All patients had defective lymphocytic apoptosis, or programmed cell death, which was due to specific Fas (APT1 [TNFRSF6]) mutations in 15 patients.
CONCLUSION: Patients with ALPS demonstrate nonspecific but often dramatic imaging findings of lymphoproliferative disorders, such as adenopathy, splenomegaly, thymic enlargement, and hepatomegaly. The stability of the clinical findings over months to years and the pattern of lymph node echogenicity may suggest the diagnosis of ALPS.