Giant cell tumor of the tendon sheath: Magnetic resonance imaging findings in 38 patients.

The present study aimed to investigate the value of magnetic resonance imaging (MRI) in the diagnosis of giant cell tumor of the tendon sheath (GCTTS), including localized (L-) and diffuse (D-) types. A total of 38 patients with GCTTS, including 31 with L-GCTTS and 7 with D-GCTTS, diagnosed by surgery and pathology, were retrospectively analyzed. All patients underwent MRI examination. Of the 31 patients with L-GCTTS, the tumors were located in the hand and wrist (18 patients), the ankle and foot (10 cases), the knee joint (2 cases) and the temporomandibular joint (1 case). All 31 lesions were either located in relation to a tendon or were partially/completely enveloping it and all were well marginated. With respect to the 7 D-GCTTS patients, the tumors were located in the ankle and foot (6 cases) or the hand and wrist (1 cases). All 7 lesions presented as an aggressive soft tissue mass infiltrating the tendon sheath and adipose tissue around the joint. The characteristic internal signal of GCTTS, including L-GCTTS and D-GCTTS, was demonstrated by MRI examination. MRI is currently the optimal modality for preoperative assessment of tumor size, extent and invasion of adjacent joint and tenosynovial space.

Inflammatory pseudotumor of the pineal region: First reported case.

Inflammatory pseudotumors originating in the central nervous system (CNS) are quite rare. To the best of our knowledge, the present study reports the first case of a inflammatory pseudotumor that developed in the pineal region, and describes the neuroimaging, morphological and immunohistochemical findings. A 53-year-old male presented with hearing loss that had been apparent for 1 year and blurred vision that had persisted for 10 months. Magnetic resonance imaging (MRI) demonstrated a homogeneously-enhanced mass in the pineal region and obstructive hydrocephalus. A pathological examination revealed that the lesion was comprised predominantly of spindled cells in a collagenous background, with dense infiltrates of small lymphocytes, plasma cells and uninucleated histiocytes. Immunopositivity for cluster of differentiation (CD)138 was noted. Immunohistochemical staining showed that the cells were immunonegative for glial fibrillary acidic protein, S-100, placental alkaline phosphatase, neurofilament and Pit-Oct-Unc class 5 homeobox 1. The Ki-67 labeling index was <5%. The lymphocytic infiltrates consisted of CD3- and CD43-positive T-cells, and CD20- and CD79A-positive B-cells. Plasma cells displayed polytypic reactivity for immunoglobulin κ and λ light chains. Based on the MRI and the morphological and immunohistochemical analysis, a diagnosis of an inflammatory pseudotumor was formed. The patient underwent a surgical resection of the tumor and currently has a good prognosis.