Light micrograph section through an adult parathyroid gland showing a oxyphilic cell nodule. Oxyphilic cells have an eosinophilic cytoplasm and are larger than the chief cells, which can be seen in the upper right corner of the image. These cells are arranged in cords separated by connective tissue spaces endowed with very abundant capillaries as in all endocrine glands. Large nodules of oxyphilic cells become more abundant as the individual ages.