The significance of paravacuolar granules of the thyroid. A histologic, cytologic and ultrastructural study.
ABSTRACT The presence of the so-called "paravacuolar granules" in thyroid follicular cells has been associated with increased metabolic activity of the gland, regressive changes, degeneration, phagocytic activity and benign papillary hyperplasia. During the course of a review of the intraoperative cytologic preparations and corresponding histologic sections from 73 thyroid cases, the presence of granules within follicular cells was noted in 25 cases (18 adenomatous or colloid goiters, 3 follicular adenomas, 2 papillary carcinomas, 1 follicular carcinoma and in thyroid tissue surrounding a follicular adenoma in 1 case). Histochemical and ultrastructural studies showed the granules to consist of lysosomes containing hemosiderin or lipofuscin pigments. These findings indicate that the presence of paravacuolar granules in thyroid cells is a common nonspecific finding that simply reflects: (1) the erythrophagocytic capability of the follicular epithelial cells, which results in the accumulation of iron within lysosomes, and (2) the accumulation of lipofuscin pigments within lysosomes as a result of degradation of endogenous cellular material.
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ABSTRACT: Thyroid nodules are common and, depending on the detection technique used, can affect 50% or greater of the population. The primary diagnostic test to assess the nature of these nodules is fine-needle aspiration cytology. Most thyroid nodules are benign and often are multiple. However, the morphology of these nodules may mimic neoplasms showing features such as papillary growth, micro follicles and even oncocytic metaplasia. Lesions with these features may be considered in-determinant, and often require surgical excision to define their nature. The role of cytopathology in this area is to screen those definitely benign nodules, thus preventing surgery and reassuring both the patient and the clinician. In this review, we demonstrate many of the morphological manifestations of nodular goiter and stress the necessity of careful preparatory techniques. Although the past several years have witnessed the development of molecular testing to refine diagnostic cytology in the thyroid, it is still the role of the cytopathologist to identify those "indeterminant" nodules which should be tested. Thus, the cytopathologist contributes both an essential diagnostic and an important cost saving role which hopefully will continue in the future.Best Practice & Research Clinical Endocrinology & Metabolism. 01/2014;
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ABSTRACT: If the entire discipline of diagnostic cytopathology could be distilled into a single theme, it would be the Papanicolaou stain. Yet it was the Romanowsky stain upon which the discipline of cytopathology was founded. Both stains are used today in the cytopathology laboratory, each for a different and complementary purpose. We trace the history of cytopathological stains and discuss the advantages and limitations of Romanowsky-type stains for cytological evaluation. We also provide suggestions for the advantageous use of Romanowsky-type stains in cytopathology.Biotechnic & Histochemistry 04/2011; 86(2):82-93. · 0.67 Impact Factor
- Endocrine Pathology 12/2010; 22(1):31-4. · 1.60 Impact Factor