Morphology of healthy human parathyroid glands in cytologic smears

OBJECTIVE: To compare the morphology of different parenchymal cell types in healthy human parathyroid glands (HPGs) in cytologic smears with their structure on histologic sections and to establish criteria for their recognition in smears. STUDY DESIGN: The HPGs of 47 subjects (27 females and 20 males) were incidentally removed during surgery on the thyroid gland. The tissue of glands with a normal macroscopic and microscopic appearance was analyzed in cytologic smears and on histologic sections. RESULTS: In cytologic smears (as well on histologic sections), dark and light chief cells predominated. Dark chief cells, which were more numerous than light ones, had a smaller nucleus without a visible nucleolus. The nucleus of light chief cells was larger with 1 or 2 nucleoli visible. The cytoplasm of both types of chief cells was poorly defined, grey-blue and often vacuolated. In the smears, the cytoplasm of oxyphilic cells was dense, gray-rose and well defined. In dark oxyphilic cells, the nuclei were smaller and without a visible nucleolus. Light oxyphilic cells had a larger nucleus and visible nucleolus. CONCLUSION: The identification and distribution of 4 parenchymal cell subtypes in the smears of pathologically altered HPGs may yield insights into the possible role of these cells in a specific disease.