Imaging findings in a rare case of alveolar, hepatic and splenic sarcoidosis presenting with thrombotic thrombocytopenic purpura

Abstract

Thrombotic thrombocytopenic purpura (TTP) is an acute haematological disorder characterized by severe ADAMTS13 enzyme deficiency, leading to consumptive thrombocytopenia, mechanical haemolysis, and organ damage. Its association with multisystemic sarcoidosis is extremely rare and, to the best of our knowledge, described in only two cases so far. We present the case of a 52-year-old woman with TTP and antibodies anti-ADAMTS13, showing computed tomography (CT) and magnetic resonance imaging (MRI) evidence of pulmonary, hepatic, and splenic lesions initially reported as ischemic/inflammatory changes. A follow-up MRI of the abdomen revealed increased evidence of the liver lesions, focal intrahepatic bile duct dilatation, splenic lesions, and enlarged hepatic hilar nodes. The follow-up chest CT showed increased evidence of the parenchymal lung consolidations. Given the radiological persistence of those alterations and the history of TTP, the hypothesis of an IgG4-related disease was then made. The IgG4 levels were found to be normal, while the histological examination of the liver revealed non-necrotizing granulomatous chronic inflammation. Elevated levels of angiotensin-converting enzyme were found, and the QuantiFERON-TB Gold test was negative for tuberculosis infection. Thus, the overall clinical picture was consistent with multisystemic sarcoidosis (alveolar, hepatic, and splenic). The diagnosis of sarcoidosis, already challenging due to the variability of its clinical presentation, can become even more complicated when it manifests with uncommon haematological manifestations such as TTP, along with non-specific extra-pulmonary involvement. While imaging aids in documenting organ damage, the definitive diagnosis of sarcoidosis necessitates histologic confirmation of noncaseating granulomas and the exclusion of other possible granulomatous diseases.