[A recurrent case of TSH-PRL secreting microadenoma following hypothyroidism]

A thirty-seven-year-old housewife whose chief complaints were recurrence of galactorrhea and amenorrhea three years after having a selective adenomectomy. Hormonal examination done as a result of the continuation of the endocrinism revealed a hyperprolactinemia and high level of TRH due to hypothyroidism. Serum prolactin responded to neither TSH stimulation nor L-Dopa suppression tests. In addition, serum TSH did not react to TRH test. Contrast enhancement CT showed an intrasellar enhancing mass the size of which was less than 1 cm in diameter. A unilateral septal transsphenoidal operation was performed; and a soft white-yellowish mass 7 X 5 X 5 mm in size was found in the left inferolateral aspect of the pituitary gland. Histological studies of frozen sections of this revealed it to be a pituitary adenoma, with the border between tumor and normal tissue being quite distinct. Immunocytochemical diagnosis further confirmed it to be both PRL and TSH producing adenoma. Electron microscopy showed more than three different hormone-producing cells. The PRL cells contained large, and the TSH cells had small hormone granules; but some tumor cells contained secretory granules of both sizes suggesting production of both PRL and TSH in the cytoplasm. It is necessary in the management of patients like this, during the post-operative period, to adequately institute a thyroid hormone replacement therapy so as to prevent recurrence.