Galera-Davidson H

Inmunohistochemical Profile of Solid Cell Nest of Thyroid Gland

It is widely held that solid cell nests (SCN) of the thyroid are ultimobranchial body remnants. SCNs are composed of main cells and C cells. It has been suggested that main cells might be pluripotent cells contributing to the histogenesis of C cells and follicular cells, as well as to the formation of certain thyroid tumors. The present study sought to analyze the immunohistochemical profile of SCN and to investigate the potential stem cell role of SCN main cells. Tissue sections from ten cases of nodular hyperplasia (non-tumor goiter) with SCNs were retrieved from the files of the Hospital Infanta Luisa (Seville, Spain). Parathormone (PTH), calcitonin (CT), thyroglobulin (TG), thyroid transcription factor (TTF-1), galectin 3 (GAL3), cytokeratin 19 (CK 19), p63, bcl-2, OCT4, and SALL4 expression were evaluated by immunohistochemistry. Patient clinical data were collected, and tissue sections were stained with hematoxylin–eosin for histological examination. Most cells stained negative for PTH, CT, TG, and TTF-1. Some cells staining positive for TTF-1 and CT required discussion. However, bcl-2, p63, GAL3, and CK 19 protein expression was detected in main cells. OCT4 protein expression was detected in only two cases, and SALL4 expression in none. Positive staining for bcl-2 and p63, and negative staining for PTH, CT, and TG in SCN main cells are both consistent with the widely accepted minimalist definition of stem cells, thus supporting the hypothesis that they may play a stem cell role in the thyroid gland, although further research will be required into stem cell markers. Furthermore, p63 and GAL-3 staining provides a much more sensitive means of detecting SCNs than staining for carcinoembryonic antigen, calcitonin, or other markers; this may help to distinguish SCNs from their mimics.

Decreased expression of calcium receptor in parathyroid tissue in patients with hyperparathyroidism secondary to chronic renal failure

The response of parathyroid cells to serum calcium is regulated by a calcium-sensing receptor protein (CaR). In patients with chronic renal failure, hypocalcemia contributes to the parathyroid hyperplasia and increased parathyroid hormone secretion characteristic of secondary hyperparathyroidism (sHPT). However, patients with uremia also display reduced sensitivity to extracellular calcium; this seems to be owing to an alteration of the receptor mechanism. This study examined calcium receptor expression in the parathyroid tissue of patients with sHPT, using immunohistochemical technicques and comparison with normal tissue and parathyroid glands of patients with primary hyperparathyroidism. In all the glands studied, immunostaining was more intense in chief cells than in oxyphilic, transitional, and clear cells. The parathyroid glands of patients with sHPT displayed significantly reduced expression of CaR with respect to morphologically normal ones; a very similar reduction is reported in adenomas. Furthermore, in glands displaying multinodular hyperplasia, expression was less marked in nodule-forming cells than in internodular areas. The decreased expression of calcium receptors in the parathyroid tissue of uremic patients was thought to be owing to the different cell populations present; these parathyroid glands contained predominantly transitional, oxyphilic, and clear cells, which normally express fewer receptors than chief cells, which are more abundant in normal glands.

Expression of neuropeptides and other neuroendocrine markers in human phaeochromocytomas

AIMS Phaeochromocytomas may produce several neuropeptides as they are considered neuroendocrine tumours. Nevertheless, studies are scarce and no clear predictive biologic value has been stablished in the case of neuropeptides expression. METHODS We have investigated immunohistochemically the neuropeptides expression of a serie of 36 phaeochromocytomas: 25 sporadic, seven familial type MEN (multiple endocrine neoplasm) and four familial phaeochromocytomas not associated with MEN syndrome. The reactivity for neuron-specific enolase (NSE), synaptophysin, vasoactive intestinal peptide (VIP), chromogranin A, calcitonin, ACTH, somatostatin and HMB-45 was tested according to the avidin-biotin complex (ABC) method using polyclonal antibodies. RESULTS Phaeochromocytomas have a multiple synthetic activity as main neuroendocrine feature. Despite phaeochromocytoma tumour cells heterogeneity chromogranin and synaptophysin are the most common neuropeptides synthesised, as they are associated with the presence of neuroendocrine storage granules. We find a statistically significant higher synthesis of corticotrophin hormone in familial phaeochromocytomas than in sporadic forms, on the contrary the synthesis of VIP is statistically associated with sporadic forms of phaeochromocytomas. We also found a direct relation of ACTH and overexpression and malignant tumours and a positive relationship between NSE and benign forms of phaeochromocytomas.

HYALINIZING TRABECULAR CARCINOMA OF THE THYROID GLAND : REPORT OF TWO CASES OF FOLLICULAR CELL THYROID CARCINOMA WITH HYALINIZING TRABECULAR PATTERN

Recently tumors have been reported that have an architectural pattern and cellularity similar to hyalinizing trabecular adenoma and show either parafollicular differentiation or histological findings suggestive of malignant neoplasm of the follicular cells. This study describes two cases of thyroid carcinoma of follicular cells that displayed a hylinizing trabecular pattern. The first case was a 25-year-old euthyroid woman with a cold thyroid nodule in the right lobe. On fine needle aspiration a diagnosis of papillary carcinoma was rendered. The thyroidectomy disclosed a 2-cm, firm, brown, encapsulated tumor in the right lobe. The tumor had a growth pattern and cytologic features similar to those described in hyalinizing trabecular adenoma. The differences between these neoplasms were the presence of mitotic figures, prominence of the nucleolus, capsular blood vessel invasion, and microtubule groups in the endoplasmic reticulum. The second case was a 19-year-old euthyroid woman with a cold thyroid nodule in the left lobe. A cytologic diagnosis of follicular proliferation was rendered. A 4-cm, firm, whitish, encapsulated nodule was found in the left lobectomy. The tumor cells were arranged in two clear-cut patterns: a trabecular hyalinizing pattern with a small focus of papillary growth, and a follicular pattern. These findings confirm the existence of malignant thyroid tumors with a hyalinizing trabecular pattern and illustrate the nonspecificity of this peculiar pattern, since it may also be seen in papillary carcinomas of the thyroid. The relationship between hyalinizing trabecular adenoma and papillary carcinoma of the thyroid is commented on.

Nuclear DNA in anaplastic thyroid carcinoma with a differentiated component

Fifteen cases of anaplastic thyroid carcinoma, including eight cases with a differentiated component, were studied by DNA analysis. All areas of anaplastic carcinoma showed an aneuploid DNA content. The eight cases of anaplastic carcinoma with differentiated component (two follicular carcinomas, two papillary carcinomas, one Hürthle cell carcinoma and three poorly differentiated carcinomas) exhibited aneuploid DNA content in the differentiated area of the tumour. Karyometric parameters allowed a fairly clear separation between giant cell, spindle cell and differentiated components. The results support the hypothesis that patients with aneuploid differentiated carcinoma represent a higher risk group and are probably more prone to developing anaplastic carcinoma.

Diagnostic problems in thyroid FNAs

The use of FNA cytology to diagnose pathologic conditions of the thyroid has increased considerably in recent years, particularly since it has reduced by half the number of patients undergoing surgery. On the one hand, this diagnostic technique has attracted a certain amount of well justified criticism, but on the other, recent cytohistologic correlations and new scientific knowledge are continually improving its application. We shall discuss the latter aspect in more detail and deal with some simple but informative points which the pathologist may find useful in daily practice. Diagn. Cytopathol. 1997;17:422–428.

Quantitative changes in the frequency and distribution of the C-cell population in the rat thyroid gland with age

SummaryThe development of calcitonin cells (C-cells) was investigated in rat thyroid glands from birth to 120 days, using an immunoperoxidase technique and a point-counting method. The proportion of C-cells to follicular cells was 4.5% on the day of birth and increased progressively to 10.4% by 120 days. The highest density of C-cells was noted in the mid-region of the lobes along a longitudinal axis. The caudal and cephalic regions of the lobes contained smaller numbers of C-cells. The C-cells tended to be more numerous in the posterior aspects of the lobes. Although the numbers of C-cells in 120-day-old animals were markedly increased as compared to animals at the time of birth, the cell distributions within the glands were similar at all ages.

Pulmonary vein myxoid leiomyosarcoma.

A case of myxoid leiomyosarcoma located in the right pulmonary veins is presented. The patient complained of progressive dyspnea, orthopnea, sputum cruentum and right chest pain. Angiography revealed an obliteration of right pulmonary veins by a tumor mass that expanded into the left atrium. Histologically, the lesion contained densely packed fusiform cell areas that alternated with other much less cellular and richer in interstitial myxoid matrix. The tumor cells showed specific immunoreactivity to desmin antibodies and contained abundant thin filaments with focal densities and micropinocytic vesicles.

Dipeptidyl aminopeptidase IV in the cytologic diagnosis of thyroid carcinoma.

Recently, the demonstration of DAP IV activity in thyroid cells aspirates has been proposed as an useful tool for the diagnosis of malignancy. We have studied the enzymatic activity of DAP IV, using the modified method of Lodja, in a series of 336 selected aspirates of the thyroid gland with the following cytologic diagnosis: 236 nodular hyperplasias, 60 follicular proliferations, eight Hashimotos thyroiditis, eight Hürthle‐cell proliferations, 20 papillary carcinomas, two anaplastic carcinomas, and two medullary carcinomas. The results were subjectively evaluated on the basis of staining intensity and extension in a minimum of 200 cells. Strong‐to‐moderate enzymatic activity with an extension of more than 40% of the cells were exclusively seen in follicular‐cell derived carcinomas (papillary carcinoma, Hürthle‐cell carcinoma, and follicular carcinoma). Medullary carcinoma, anaplastic carcinoma, and benign conditions were negative or weakly stained. Cytohistologic correlation in 88 patients operated on showed the following results: 26 nodular hyperplasia (18 nodular hyperplasia and eight follicular adenomas), 36 follicular proliferation (24 nodular hyperplasia, six, adenomas, three papillary carcinomas, three follicular carcinomas), two Hürthle‐cell proliferation (one Hürthle‐cell adenoma and one Hürthle‐cell carcinoma), 20 papillary carcinomas, two medullary carcinomas, and two anaplastic carcinomas. DAP IV staining was moderate to strong and extensive in all malignant tumors initially diagnosed as follicular or Hürthle‐cell proliferations.

Fine needle aspiration cytology of an acral myxoinflammatory fibroblastic sarcoma: case report with cytological and cytogenetic findings.

A 29-year-old man presented with a slow-growing, painless mass on the third finger of the left hand. This began as a distal swelling but later progressed towards the palm, eventually affecting the whole finger. The patient underwent surgery to drain abundant mucoid material; the initial surgical diagnosis was a large ganglion cyst. One month later, the patient consulted because of a new swelling affecting the distal twothirds of the finger (Figure 1). Fine needle aspiration was performed. What is your diagnosis? Acral myxoinflammatory fibroblastic sarcoma (AMIFS) is the most recent form of fibrosarcoma to be reported so far. It is considered to be a unique lowgrade sarcoma with myxoid stroma, inflammatory infiltrate and virocyte-like cells (WHO) that may readily be confused with inflammatory processes, such as pigmented villonodular tenosynovitis, or various reactive fibroinflammatory processes. One of its distinctive features is a preference for the hands and feet, but it has also been reported in more proximal areas, such as the forearm, upper arm, thigh and even the neck. Its clinical, histological, inmunohistochemical and ultrastructural features have been well documented in several series, but few reports are available on fine needle aspiration (FNA) cytology findings. Cytogenetic reports are also scarce. Two reports describing complex karyotypes present different findings: a reciprocal translocation between chromosomes 1 and 10 t(1;10)(p22;q24) with loss of chromosomes 3 and 13, as against supernumerary ring chromosomes and a derivative chromosome 13, with additional material on the short arm. This paper reports on the cytological and cytogenetic findings in a recurrent AMIFS on the third finger of the left hand of a young adult.