Extraosseous Tc-99m methylene diphosphonate concentration in the forearm following post-mastectomy lymphatic obstruction

A 42-year-old female patient with a past history of right breast cancer and recent onset swelling of the right forearm underwent routine whole-body bone scintigraphy with Tc-99m methylene diphosphonate, 2 years after a modified radical mastectomy. Diffuse soft tissue tracer concentration was seen in the right forearm. Subsequent lymphoscintigraphy using Tc-99m sulphur colloid revealed obstructed lymphatic drainage in the right upper limb.