No abstract

A 53-year-old man presented with a history of progressive abdominal distention for 1 year. Physical examination revealed large palpable masses in the bilateral flank regions. Contrast-enhanced CT of the abdomen showed bilateral, symmetrical large perinephric masses with fat attenuating areas, which was further confirmed on MRI. CT of the paranasal sinuses revealed circumscribed extraconal soft tissue mass in the left orbit, causing scalloping and erosion of the left orbital roof. Fluorine-18 fluorodeoxyglucose (FDG) positron emission tomography/CT showed FDG uptake in the bilateral perinephric masses. Based on imaging appearance, a diagnosis of Erdheim-Chester disease (ECD) was suggested. Ultrasound-guided biopsy from perinephric masses revealed a sheet of histiocytes with sprinkled lymphocytes and plasma cells in the background. The histiocytes were immunopositive for CD68, S100 and immunonegative for CD1a, which confirmed the diagnosis of ECD. The patient was started on interferon-α-2a and showed symptomatic improvement.

No abstract

Langerhans cell histiocytosis (LCH) is a common cause of multifocal lytic skeletal lesions in children. However, multifocal osseous tuberculosis can affect children and mimics LCH on imaging, especially in endemic regions. We report cases with atypical manifestations of multifocal osseous tuberculosis which were presumptively diagnosed as LCH. The findings of our series of cases suggest that on computed tomography (CT) irregular sclerotic margins, abscess formation, sclerosis of involved bone, and button sequestrum point toward a diagnosis of multifocal osseous tuberculosis, especially in endemic regions.