Медицина/8.Морфология

Artykbayeva N.T., Mambetova G.K..

Kazakh National Medical University named after S.D. Asfendiyarov, Almaty Clinical Hospital №1, Almaty, Kazakhstan

Morphology of atypical follicular adenomas of thyroid glands

The purpose of the following study:

The purpose of this study was to research the morphological features of atypical follicular adenoma (AFA) of thyroid gland.

Material and Methods. In this work were studied 1011 stories of disease and operational material of thyroid gland, received during surgery in the City Clinical Hospital №1, Almaty, from 1992 to 2007 and medical center «HAК» from 2003 to 2007. 47 cases were selected with AFA. The age of patients was in the range of 15 to 71 years (middle age 43 years). AFA frequently were in women in the age range between 31 and 50 years, the preponderance of women diagnosed in the ratio: 9:1. Research methods: histological, electro-microscopy.

Results. Macroscopic AFA defined as a node with clear outline, well expressed capsule with diameter from 0,5 to 3,5 cm. While microscopic study of AFA the heterogeneity tumors were noted. Thyrocytes were normal and enlarged size, cubic and cylindrical shape, with normal color cytoplasm, in only one case in gyurtcellular areas of tumor cytoplasm was eosinophiled. In 66% cases of AFA were determined different degree of thyrocyte dystrophic changes in the form of vacuolation and fragmentation of cytoplasm. Dystrophic changes in the stroma were in the form of phlegm (31,6%), hyalinosis (36,8%), calcification (10,5%), cystic degeneration (7,9%), fat dystrophy (10,5%). In all cases, were determined polymorphism of cells and nuclei. The nuclei were identified round, oval, fusiform, irregular shapes. The size of the kernels ranged from the ordinary to the giant. Nuclear-cytoplasmic ratio in the lower part of the cases was normal (10,5%), in most of the small and significantly shifted upwards nucleus (89,5%). In 7,9% of stroma looked sparse, 50% measured in the form of thin fibrous structures, 42,1% - in the form of dense collagen structures. Lymphoid infiltration of stroma was scarce in 36,8%, moderate in the form of scattered clusters of lymphocytes in 39,5% expressed with the formation of lymphoid follicles – to 23,7%. The fact that even when lymphoid infiltration of stroma was minimal, in subcapsular zone densities were observed expressed lymphocytes, often with the formation of lymphoid follicles. Capsule lymphocyte infiltration was not only in 1 case (2,6%). In all other cases, there lymphoid infiltration with varying degree, and at different depths: 17 cases of infiltration were the local (44,7%), 20 – diffuse (52,7%). In all cases, there was expressed as intrafollicular thyrocyte proliferation, and in interfollicular space. Invazin structures in the tumor capsule wall or receptacles have been noted.

When photooptical study of AFA half-thin sections in the cytoplasm thyrocyte identified multiple dystrophic changes in the form of fragmentation and vacuolation. Cell nucleus in different fields of view were different in size and colors. Part of kernels – dark, round, oval, uncertain, irregularly shaped due to the winding contours of nuclear membrane intussusception Mitozy were not identified. Stroma moderately expressed as a delicate fibrous structures and dense collagen structures.

Electron-microscopic examination confirmed the AFA data obtained in the study of half-thin sections and identified the presence of a large range of cell types: light, dark and intermediate cells of varying degrees of differentiation Light cells were rounded and elongated in shape and contain large round a nucleus of high euchromatin. Heterochromatin display premarginally individual clusters. Granular endoplasmic reticulum (GER) was weak. GER tubules were narrow or expanded.

Mitochondria were of various sizes and shapes. There were installed matrix form with edematous and numerous crysts. Secretory granules were osmiophilled smaller, more focused in part subnuclear cells. Apical surface is covered with microfibre.

Transduction space expanded at selected sites. Basal membrane winding. The dark cell with the nucleus had hyperhromic contours of the nuclear envelope. «Lit» type of dark cells attached dramatically expanded until GER cylinders tubules. Numerous mitochondria were clear and transparent matrix and crysts. Basal membrane has been developed and had little jerky look. Intermediate hyaloplasmic cells were less pronounced density. GER tubules were enlarged. The signs of a specific cell-osmiophilled secretory granules have been observed. Mitochondria were many, had a round, elongated shape, electron-transparent matrix and rare crysts. At the apical surface microvilli located. There hyaloplasms swelling and destruction of organelles, mostly in the dark cells.

Conclusion. Thus, the AFA has expressed polymorphism, proliferation of thyrocyte, shifting of nuclear cytoplasmic ratios upwards kernel, expressiveness of different dystrophic changes, the presens of varying degrees of lymphoid stroma and capsules infiltration, the existence of multiple forms of less differentiated cells (light and dark), reflecting the aggressive nature of AFA and proximity to the AFA follicular cancer.