We present the case of a 43-year-old man who presents pain and functional impotence in the left wrist of one year of evolution. Upon examination, an indurated tumor adhered to deep planes is found in this location. Following findings on computerized axial tomography (CT) of images consistent with osteochondroma versus peripheral chondrosarcoma (Figure 1), a bone scan was requested. This bone scintigraphic study in three phases of the upper limbs and a subsequent full-body image (Figure 2), showed the early arrival of the tracer with an increase in the vascular pool of slight-moderate intensity in the distal portion of the left radius (arrow), which persisted with greater intensity in late images. No other diseased findings were observed in the rest of the skeleton. These findings revealed increased vascularity and osteoblastic activity at the distal end of the left radius.

Figure 1.  3D reconstruction of the left wrist using CT 

A biopsy was carry out, with a pathological result of osteochondromatous proliferation compatible with Nora’s lesion, confirming this diagnosis after surgical resection. Nora's lesion occurs predominantly in the second or third decade of life¹,², without gender differences³, mainly affecting the extremities. Of uncertain etiology⁴,⁵, it consists of an excretory and exophytic lesion that originates in the bone cortex, formed by bone, cartilaginous and fibrous tissue, with nuclear atypia⁶,⁷. Bone scan allows us to know the metabolic characteristics of this lesion. Given its aggressive nature, a differential diagnosis should be made with malignant lesions such as osteosarcoma⁸.

Figure 2.  Tc99m-diphosphonates three-phase upper limb and late full-body bone scan