Keimyung Medical Journal, Vol.2(2) : 115-135, 1983
Experienced were two cases of functional pheochromocytoma of adrenal glands with pertinent clinical findings. An electron microscopic study was performed on one case (S83—3304) with particular reference to delineation of chromaffin granule specificity and that of type of catecholamine content. Also measurement v/as made for the dimension of the catecholamine granules, using a morphometric instrument, the graphic image analyzer, AIM 66 (Ladd, USA).
Results observed were summarized as follows：
1. Light microscopically, case 1 (S83—3304) showing clusters and cords of cells with abundant granular eosinophilic cytoplasm. These tumor cells were separated by thin bands of connective tissue with plentiful thin-walled blood vessels in close proximity to tumor cells. Their nuclei v/ere ovoid and medium-sized. Occasional hyperchromatic and degenerating forms. Case 11 (S83—6514) was much more aggressive and atypical in that this tumor showing irregular and hyperchromatic nuclei with occasional tumor giant cells to the extent to be suggestive of anaplastic neoplasm.
2. Electron microscopically, the neoplastic chromaffin cells were polymorphic with numerous processes interdigitating with invagination into the adjacent cells. The large nuclei with prominent nucleoli revealed coarse heterochromatin clumps attached to the inner-aspect of nuclear membrane. In the cytoplasm, catecholamine granules with varying size were scattered and each was surrounded by limiting membrane. The electron dense portion of each epinephrine granule was composed of the finest subparticles which varied in diameter, from 50 to 100A. Whereas norepinephrine granules were quite different from epinephrine granules, in that there noted a clear space or halo interposing between the limiting membrane of the granules and the electron-dense core. Also the core of norepinephrine granules was more electronᅳdense and no fine granularity as noted in the case of epinephrine granules. Also present in the cytoplasms were numerous mitochondria, well-developed Golgi apparatus and some free ribosomes.
3. Morphometrically, the catecholamine granules had variable sizes, mostly from 100 to 600 nm in dimension. Norepinephrine-containing granules were larger than epinephrine-containing granules. Mean diameter of norepinephrine granules was 325 nm and that of the epinephrine granules being 281nm. The largest granule was 764 nm and the smallest granule, 3lnm, all of which belonged to the bracket of epinephrine-containing granules.