Light and electron microscopic observation of the same mammosomatotroph cell in a mixed growth hormone- and prolactin-secreting pituitary adenoma--case report.

A mammosomatotroph cell was identified in two consecutive semithin sections of conventional epoxy-embedded tissue for light microscopy and an adjacent ultrathin section for electron microscopy cut from a mixed growth hormone (GH)- and prolactin (PRL)- secreting human pituitary adenoma in a 51-year-old female. The same mammosomatotroph cell demonstrated immunostaining for both GH and PRL simultaneously by light microscopy, and was morphologically evaluated by electron microscopy. The ultrastructural features of this cell resembled densely granulated GH-secreting adenoma cells, but also contained characteristics of PRL-secreting adenoma cells.