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 lymph oproliferative syndrome (ALPS) and to relate the findings to the clinical a nd 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 featur es in 19 consecutive patients with ALPS were performed. RESULTS: Most patients presented in the 1st year of life with symptoms of a denopathy and hepatosplenomegaly. At the time of presentation to the instit ution, 12 patients had already undergone splenectomy, and 14 patients had d eveloped autoimmune disorders. All patients had multifocal adenopathy, whic h war massive in some patients; 14 of 15 patients who underwent CT of the c hest had an enlarged thymus, and all six patients who retained their spleen s and who underwent imaging had splenomegaly. Ten of 18 patients who underw ent 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 c ell death, which was due to specific Fas (APT1 [TNFRSF6]) mutations in 15 p atients. CONCLUSION: Patients with ALPS demonstrate nonspecific but often dramatic i maging findings of lymphoproliferative disorders, such as adenopathy, splen omegaly, thymic enlargement, and hepatomegaly. The stability of the clinica l findings over months to years and the pattern of lymph node echogenicity may suggest the diagnosis of ALPS.