Computer-assisted image analysis of small cell lymphoma of the thyroid gland. Comparison of nuclear parameters of small lymphocytes in lymphomas and Hashimoto's thyroiditis.

The nuclear parameters of the small lymphocytes in nine cases of small cell lymphomas of the thyroid gland and 17 cases of Hashimoto's thyroiditis were assessed by computer-assisted image analysis. The nuclear area, maximal, minimal and averaged Ferret diameters, perimeter, regularity factor and elongation factor were gauged. Statistically, the nuclear area was ascertained to be the optimum descriptor discriminating between small neoplastic and reactive lymphocytes. Application of a novel variable, combining a nuclear area cut-off value of 14 microm2 with a nuclear averaged Ferret diameter cut-off value of 4.5 micron, allows for the distinction - with a high degree of sensitivity and specificity - between small neoplastic lymphocytes in thyroidal lymphomas and the reactive lymphocytes in Hashimoto's thyroiditis.