Differential diagnosis in Rosai-Dorfman disease: A rare case of isolated hepatic presentation mimicking a metastatic tumor with positive 18-FDG uptake

Abstract

Rosai-Dorfman disease, sinus histiocytosis, liver surgery, hepatectomy Rosai-Dorfman disease (RDD) is also called sinus histiocytosis with massive lymphadenopathy, and it is caused by a histiocytic disorder with unclear etiology. It usually involves cervical lymph nodes, but it may also present with extranodal involvement. We report a rare condition of isolated hepatic RDD without nodal involvement, clinically manifested with three-month abdominal pain and tenderness of the right hypochondrium. CT-and PET-CT scans were compatible with a secondary lesion from an unknown primary tumor. Therefore, the patient underwent an atypical liver resection. Immunohistochemistry and histological results were compatible with a diagnosis of RDD. RDD is characterized by phenomena of emperipolesis, histiocytic proliferation and positive immunostaining for CD14, CD68 and S-100 protein. Cases of isolated gastrointestinal localization of RDD are particularly rare, especially in the liver. Instrumental exams might confuse RDD with other malignancies. RDD is a rare entity, which might be misdiagnosed using PET-CT due to its similarities with malignant tumors. An accurate multidisciplinary approach may help to clear diagnostic clues of this uncommon disease.

Subtly Increased Focal FDG Activity in the Liver Due to Paragonimiasis

“…Primary hepatic malignancies or metastases are most commonly considered diagnosis when focal hepatic FDG activity was observed. However, many benign etiologies 7–14 can have similar FDG PET/CT images and are difficult to distinguish based on PET/CT study alone. The MRI features of P. westermani infection of the liver should be considered in this situation.…”