Multinucleated Giant Cells’ Incidence, Immune Markers, and Significance: A Study of 172 Cases of Papillary Thyroid Carcinoma

Multinucleated giant cells (MGCs) are often detected in cases of papillary thyroid carcinoma (PTC). Their origin and significance, however, has not been established. One possibility is that they form in response to injury induced by fine needle aspiration biopsy (FNAB). Other hypotheses are that the chemically-altered colloid produced by PTC induces MGCs to act as colloidophages, or else MGCs are a non-specific immune response ingesting neoplastic follicle cells. We assigned 172 cases of PTC a semi-quantitative score for MGCs. Cases with “many” MGCs were immunohistochemically stained for AEI/AEIII, CD68, and CD163 to assess for epithelial vs histiocytic differentiation, and for thyroglobulin and TTF-1 to assess for MGC ingestion of colloid or thyroid follicle cells respectively. Overall, we identified MGCs in 100/172 (58.1%) PTC specimens; in 45 (26.2%), “many” MGCs were found, while in 55 (31.9%) MGCs were “few.” The mean sizes of PTC in cases with many as opposed to rare/no MGCs was 2.50 cm vs 1.8 [P = 0.003]. The cases of PTC with many MGCs had higher multifocality (26/45 vs 51/127 [P = 0.06]), extrathyroidal extension (21/45 vs 36/127 [P = 0.03]), and recurrence (8/45 vs 9/127 [P = 0.08]), than did cases with rare or no MGCs. The majority of patients both with and without numerous MGCs had previous histories of FNA or hemilobectomy: 40/45 and 99/127 respectively (P = 0.062). The majority of MGCs were positive for CD68 (45/45), CD163 (44/45), thyroglobulin (34/45) and negative for AEI/AEIII (44/45) and TTF-1 (44/45). These results indicate that MGCs in PTC are of histiocytic origin. Cases of PTC with many MGCs have a significantly greater likelihood of extrathyroidal extension and greater tumor size than cases with few/no MGCs. MGCs appear to be functioning largely as colloidophages

The pathology of familial breast cancer: Morphological aspects

A small proportion of breast cancers are due to a heritable predisposition. Recently, two predisposition genes, BRCA1 and BRCA2, have been identified and cloned. The morphological features of tumours from patients harbouring mutations in the BRCA1 and BRCA2 genes differ from each other and from sporadic breast cancers. Both are of higher grade than are sporadic cases. An excess of medullary/atypical medullary carcinoma has been reported in patients with BRCA1 mutations. Multifactorial analysis, however, shows that the only features independently associated with BRCA1 mutations are a high mitotic count, pushing tumour margins and a lymphocytic infiltrate. For BRCA2 mutation, an association with tubular/lobular carcinoma has been suggested, but not substantiated in a larger Breast Cancer Linkage Consortium study. In multifactorial analysis, the independent features were a lack of tubule formation and pushing tumour margins only. The morphological analysis has implications for clinical management of patients

Pleomorphic adenoma of minor salivary gland with therapeutic misadventure: a rare case report

<p>Abstract</p> <p>Background</p> <p>The benign tumors of nasopharynx are least encountered tumors in otolaryngology, as nasopharynx is considered one of notorious anatomical site for the malignant tumors. Pleomorphic adenoma of the minor salivary gland of nasopharynx and parapharyngeal space is rare. We present a pleomorphic adenoma of minor salivary gland which was mismanaged.</p> <p>Case presentation</p> <p>An adult male presented with left nostril obstruction for five months. The examination found big mass extending from nasopharynx to oropharynx. On CT scan, this tumor was quite big and extending to the parapharyngeal space. The FNAB found it a carcinoma but it did not respond to radiotherapy. The excision biopsy of tumor revealed it as pleomorphic adenoma. We found only five published reports on this tumor arising from nasopharynx.</p> <p>Discussion and conclusion</p> <p>Although, in this case report exact origin of the tumor could not be ascertained as it also appeared to be a parapharyngeal tumor but we kept the possibility of a nasopharyngeal tumor on the basis of clinical features. The pleomorphic adenoma of nasopharynx is rare. It can be misdiagnosed as malignant epithelial tumor on histopathology. The differentiation from its malignant variant is also difficult. A possibility of benign tumor should always be kept in nasopharyngeal growth with no evidence of metastasis, and histopathological diagnosis of growth should be available before any definitive treatment.</p

Caveolin-1 overexpression is an early event in the progression of papillary carcinoma of the thyroid

Caveolin-1 is a major structural component of caveolae, which are plasma membrane microdomains implicated in the regulation of intracellular signalling pathways. Previous in vitro and in vivo studies on the function of caveolin-1 in carcinoma showed controversial results, indicating that the physiological role of caveolin-1 varies according to the origin of carcinoma. In this study, we investigated caveolin-1 expression in thyroid neoplasms by means of immunohistochemistry using a rabbit polyclonal antibody against caveolin-1. Normal follicular cells did not express caveolin-1. In papillary carcinoma, caveolin-1 expression was observed in high incidence, and especially in microcancer (less than 1.0 cm in diameter), caveolin-1 was positive in all cases except one. In undifferentiated (anaplastic) carcinoma, its incidence was significantly reduced. On the other hand, all cases of follicular carcinoma and adenoma were classified as negative for caveolin-1. These results suggest that caveolin-1 may play a role predominantly in the early phase of papillary carcinoma, whereas it has little influence on follicular tumours

Human Alpha Defensin 5 Expression in the Human Kidney and Urinary Tract

The mechanisms that maintain sterility in the urinary tract are incompletely understood. Recent studies have implicated the importance of antimicrobial peptides (AMP) in protecting the urinary tract from infection. Here, we characterize the expression and relevance of the AMP human alpha-defensin 5 (HD5) in the human kidney and urinary tract in normal and infected subjects.Using RNA isolated from human kidney, ureter, and bladder tissue, we performed quantitative real-time PCR to show that DEFA5, the gene encoding HD5, is constitutively expressed throughout the urinary tract. With pyelonephritis, DEFA5 expression significantly increased in the kidney. Using immunoblot analysis, HD5 production also increased with pyelonephritis. Immunostaining localized HD5 to the urothelium of the bladder and ureter. In the kidney, HD5 was primarily produced in the distal nephron and collecting tubules. Using immunoblot and ELISA assays, HD5 was not routinely detected in non-infected human urine samples while mean urinary HD5 production increased with E.coli urinary tract infection.DEFA5 is expressed throughout the urinary tract in non-infected subjects. Specifically, HD5 is expressed throughout the urothelium of the lower urinary tract and in the collecting tubules of the kidney. With infection, HD5 expression increases in the kidney and levels become detectable in the urine. To our knowledge, our findings represent the first to quantitate HD5 expression and production in the human kidney. Moreover, this is the first report to detect the presence of HD5 in infected urine samples. Our results suggest that HD5 may have an important role in maintaining urinary tract sterility

Association of RET codon 691 polymorphism in radiation-induced human thyroid tumours with C-cell hyperplasia in peritumoural tissue

The RET proto-oncogene encodes a protein structurally related to transmembrane receptors with an intracellular tyrosine kinase domain. In human thyroid gland, the RET proto-oncogene is normally expressed in parafollicular C-cells. Thyroid C-cell hyperplasia is associated with inherited medullary thyroid carcinomas and is considered as a pre-neoplastic stage of C-cells disease. It has also been observed in thyroid tissues adjacent to follicular and papillary carcinomas. In order to study the relationship between a misfunctioning of the RET proto-oncogene and the presence of C-cell hyperplasia, we compared a series of thyroid glands presenting sporadic or radiation-associated tumours, as well as samples of unrelated normal thyroid tissues, for alteration in exons 10 and 11 of the gene and for the presence or absence of C-cell hyperplasia. Here we report a significantly higher frequency of C-cell hyperplasia present in peritumoural thyroid tissues of radiation-induced epithelial thyroid tumours, than in peritumoural of sporadic thyroid tumours or in control normal thyroid tissues (P=0.001). A G691S RET polymorphism was present with a higher frequency in radiation-induced epithelial thyroid tumours (55%) than in sporadic tumours (20%) and in control normal thyroid tissues (15%). Interestingly, this polymorphism was associated in the majority (88%) of radiation-induced tumours with a C-cell hyperplasia in the peritumoural tissues. Several explanations for this association are discussed