We report a case of a 30-year-old female patient with a painless palpable nodule in the chest wall, evaluated for osseous involvement by technetium-99m (Tc-99m) bone scintigraphy. A whole-body scan revealed numerous sites of increased tracer accumulation throughout the thorax, abdomen, and pelvis. Subsequent single-photon emission computed tomography-computed tomography (SPECT-CT) of the abdomen and pelvis showed no abnormal uptake in the bone; however, significant nonosseous tracer accumulation in calcified soft tissue metastases was noted. Pathology confirmed a high-grade ovarian papillary serous adenocarcinoma. Extraosseous uptake of bone-seeking agents in the body is often incidental findings and can be explained by various benign and malignant conditions with soft tissue calcification. In our case report, this unusual finding on bone scintigraphy was highly suggestive for malignancy, initially not considered during the clinical evaluation of the patient. It also illustrates the usefulness of additional hybrid SPECT-CT to precisely localize extraosseous uptake of Tc-99m methylene diphoshonate.