Pleomorphic adenoma of the salivary glands: correlation between gallium-67 uptake and histopathological components

We correlated 67Ga uptake and histopathological findings in pleomorphic adenomas of the salivary glands.

Sixty-two pleomorphic adenomas of the salivary glands were visually graded by degree of 67Ga uptake as negative, weakly positive or strongly positive in comparison to uptake in the nasal cavity. These adenomas were re-examined pathologically and classified as epithelial, intermediate or mesenchymal type according to their dominant histological components. The pathological presence of marginal invasion or associated sialoadenitis was also re-examined.

Eighteen adenomas were classified as strongly positive, eight as weakly positive and 36 as negative. Nine (50%) of the 18 strongly positive adenomas were of the epithelial type and the other nine (50%) strongly positive adenomas were of the intermediate type. While none of the strongly positive adenomas were of the mesenchymal type, 27 (75%) of the 36 negative adenomas were of the mesenchymal type. Six (75%) of the eight weakly positive adenomas were of the intermediate type. About half of the adenomas showed marginal invasion regardless of the grade of 67Ga uptake. None of the strongly positive adenomas were associated with sialoadenitis.

The epithelial component of pleomorphic adenomas may be responsible for 67Ga uptake. The presence of marginal invasion or associated sialoadenitis has little relation to 67Ga uptake in pleomorphic adenomas.