Clinical History
A 45-year old man was admitted to hospital due to car accident.
Imaging Findings
A 45-year old man was admitted to the emergency room, with fractures of the right ribs and scapula on the right and ipsilateral haemothorax, due to car accident. He reported a history of alcohol abuse, diabetes mellitus and HbsAg(+) ,the latter being specific serological test for hepatitis B. He also complained of dyspnea the last two months. Laboratory tests revealed: Haemoglobin 8,83 g/dl (14.0-18.0 g/dl), haematocrit 28% (40.0-52.0 %), blood glucose 170 mg/dl (70-115 mg/dl), gamma-gloutamyl transferase 273 IU/L (10-75 IU/L), alkaline phosphatase (ALP) 173 IU/dl (35-125 IU/L), lactic dehydrogenase (LDH) 264 IU/L (80-230 IU/L). Arterial blood gas showed a severe hypoxemia (PO2 55 mmHg).
Apart from a chest radiograph, conventional CT and HRCT of the chest, and abdominal CT were also performed. Chest radiograph showed fractures of the 4th to 6th ribs and scapula on the right and concomitant haemothorax. It also revealed mediastinal widening and mild prominence of linear markings in the lower lung fields (Fig.1). Conventional CT disclosed enlarged anterior mediastinal, bilateral upper and lower paratracheal, aortopulmonary window, subcarinal and bilateral hilar lymph nodes. Rib fractures and hemothorax were seen on the right (fig 2a,b). HRCT revealed extensive uneven thickening of central and peripheral bronchovascular bundles in all three lung fields, as the predominant lesion (fig 3a,b). Interlobar fissures were thickened. Centrilobular and subpleural micronodules, thickened interlobular septa and nonseptal lines were also depicted. Postcontrast abdominal CT (fig 4a,b) showed a nodular liver contour, an enlarged caudate lobe, subtle dilatation of intrahepatic bile ducts and multiple hypodense intrahepatic foci up to 5 mm in size. Splenomegaly was evident with multiple disseminated hypodense foci up to 5 mm in size. Enlarged lymph nodes at multiple stations including splenic hilum, porta hepatis, gastrohepatic ligament and celiac axis were also seen. Video-assistant thoracoscopic biopsy of the lung and mediastinal lymph node and liver biopsy were performed.
Discussion
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.
Differential Diagnosis List
Pulmonary and abdominal sarcoidosis, chronic persistent hepatitis.
Final Diagnosis
Pulmonary and abdominal sarcoidosis, chronic persistent hepatitis.
