Fibroma of tendon sheath embedded in carpal bones mimicking
A 43-year-old Chinese man was referred to the hand clinic of our institution with a painful mass in his right wrist. He had a history of injury to right hand sustained 5 months back due to fall. There was no history of malignancy. His medical history included hepatitis B.

On examination, the right wrist was slightly swollen with a palpable subcutaneous mass (diameter: approximately 2 cm); the mass was non-fluctuant and there was no obvious deformity. He also had a tender point at the anatomist's snuff-box. There was no bone crepitus or feeling of bone friction. The right wrist function was normal and there was no loss of pricking sensation in any of the fingers of the right hand. The initial diagnosis was enchondroma in the wrist.

X-ray demonstrated a rounded, well-defined, low-density mass sized 1.0 × 1.1 cm in the right scaphoid bone and trapezium bone. No abnormality was observed in the left wrist or in the wrist joint space bilaterally. On magnetic resonance imaging (MRI), the lesion exhibited intermediate intensity on T1-weighted images and appeared hyperintense on T2-weighted images. These imaging findings were consistent with the diagnosis of enchondroma.

The patient underwent lesion resection surgery. The mass (size: 2cm × 2cm × 2 cm) was hard and tough in consistency, grey-white in color, and well delineated from the surrounding tissues. The generated void was filled with artificial bone, and external fixation was performed at the surgical site.

Histopathological examination revealed edematous collagen-like stroma, spindle-shaped cells with unclear lobulated structure, hyaline degeneration, insignificant cell atypia, and a small amount of mitoses. No giant cells or inflammatory cells were identified. A diagnosis of fibroma of tendon sheath was established. At 6-month follow-up, the surgical wound had healed well with no signs of recurrence.

Source: Medicine: April 2019 - Volume 98 - Issue 16 - p e15262

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