Bone scintigraphy in growth hormone-secreting pulmonary cancer and hypertrophic osteoarthropathy

Hypertrophic osteoarthropathy was detected in a 55-yr-old man with pulmonary squamous-cell cancer by bone scintigraphy using 99mTc-hydroxy methylene diphosphonate (HMDP). Intense symmetrical uptake was demonstrated in the distal portions of the long bones as was the parallel tract sign, accompanied by markedly elevated serum growth hormone levels. After chemoradiotherapy for pulmonary cancer, the arthralgia disappeared and scintigraphic findings and serum growth hormone levels improved, suggesting that ectopic production of growth hormone in the pulmonary tumor had been associated with hypertrophic osteoarthropathy. These findings indicate that bone scintigraphy is useful for detecting hypertrophic osteoarthropathy, and assessing alterations in hypertrophic osteoarthropathy activity post-treatment.