Nuchal-type Fibroma of the Coccyx: CASE REPORT
A 29-year-old man without any particular medical history presented to our institution with a 6-year history of asymptomatic lump on the coccyx area. The patient complained that it had been gradually growing. On physical examination, the lesion was 3 x 4 cm sized, not tender, subcutaneous mass on the left side of coccyx area (Fig. 1). There were no other specific physical and laboratory findings. MRI scans revealed a relatively ill-defined lesion on subcutaneous fat layer of posterior to coccyx. This lesion appeared low signal intensity on both T1 and T2-weighted images, and measured 4.0 x 3.6 x 1.7 cm. It was attached to, but had not extended into, the coccyx (Fig. 2).
Fig. 1. 3 x 4 cm sized, not tender, subcutaneous mass on the left side of coccyx area.
Fig. 2. T1-weighted MR imaging showing ill-defined low signal intensity on subcutaneous fat layer of posterior to coccyx.
For further diagnosis and treatment, we performed total excision. Grossly, the mass showed unencapsulated, homogenous whitish fibrotic appearance. It was poorly demarcated, and attached somewhat to surrounding tissue. Histopathologic examination of this mass revealed sheets of dense collagen bundles with sparsely scattered fibroblasts (Fig. 3A, B). And there were some interspersed adipose tissue (Fig. 3C), and entrapped nerve fibers (Fig. 3D). These findings were consistent with those of nuchal-type fibroma. About two years after the operation, there has been no recurrence of the lesion. levitra plus
Fig. 3. Histopathology showing poorly demarcated, dense collagen bundles with sparsely scattered fibroblasts (A, B). There were also some interspersed adipose tissues (C), and entrapped nerve fibers (D) (H&E, A: x 40, B-D: x 200).