Sarcoidosis is a systemic disease of unknown origin, characterized histologically by noncaseating granulomas. It can involve almost any organ although most of the morbidity and mortality is associated with pulmonary involvement. The most common HRCT pattern of pulmonary sarcoidosis consists of nodules, usually less than 5 mm in a perilymphatic distribution, along bronchovascular bundles, adjacent to interlobular septa and subpleurally, associated with mediastinal and symmetrical hilar lymphadenopathy. An upper lobe predominance is common. However when diffuse thickening of bronchovascular bundles is the prominent feature, as in this case, lymphangitic carcinomatosis should also be considered (1).
The most commonly reported findings of abdominal sarcoidosis on CT include homogenous hepatosplenomegaly in 30%-38% of patients and abdominal lymphadenopathy in 27%-39% (2). The least common pattern, as observed in our patient, is multiple focal liver and splenic nodules ranging from 2mm -2cm, in 5%-15% of cases (2,3) . Although abdominal lymphadenopathy and splenomegaly could be attributed to liver cirrhosis suspected from liver contour, it was not the case with focal hepatosplenic nodules. It is important to differentiate the nodular appearance of hepatosplenic sarcoidosis from metastatic disease, infection and lymphoma. Particularly lymphoma can be associated with abdominal adenopathy and splenomegaly. Although considerable overlap is referred with the latter entity, lymph nodes are smaller and more discrete in sarcoidosis, as opposed to larger and more confluent nodes in lymphoma (2,3).The coexistence of chronic active hepatitis and sarcoidosis as in our case, seems to be a coincidence, since there is not a known association or predisposition of sarcoidosis to viral hepatitis and vice versa. Neither routine laboratory tests of liver dysfunction nor histopathology of liver lesions alone are specific for sarcoidosis, Nevertheless, values of such tests, can simulate viral hepatitis and other diseases as well(4). Epithelioid cell granulomas, the main histopathologic finding in liver biopsies of sarcoid patients and other less common pathologic features of sarcoidosis, can also be found in other entities including primary biliary cirrhosis, ,chronic active hepatitis, tuberculosis, Crohn’s disease (5). A diagnosis of sarcoidosis requires a combination of clinical, radiological, immunological and pathological parameters, namely radiological signs of mediastinal/hilar involvement or lung involvement, raised serum angiotensin converting enzyme, raised serum calcium, positive Kveim test, uveitis, and histological findings of well circumscribed granulomas in other organs, most commonly lungs and lymph nodes.
The combination of discrete, enlarged mediastinal, hilar and abdominal lymph nodes with peribronchovascular thickening and nodular hepatosplenic lesions, even in a patient with confusing clinical presentation and history, should arouse the suspicion of sarcoidosis.