Tag Archives: immunohistochemistry

Merkel cell carcinoma- particularities and morphological aspect of a unique and rare entity

DOI: 10.2478/amma-2024-0008

Introduction: Merkel cell carcinoma is a very rare malignant neoplasm which presents high aggressivity, high recurrence rate and has metastatic potential. Our purpose is to present the histological and immunohistochemical particularities of Merkel Cell Carcinoma while reviewing potential differential diagnoses and challenges that we can encounter in daily practice.
Case presentation: We present the case of an 86-year-old female patient who presented with a nodular tumour located in the left forearm, raising suspicion of a soft tissue tumour. The histological appearance of this unique type of cancer is highlighted on the Haematoxylin-eosin stain as a solid tumour composed of nests and chords of monomorphic cells. The nuclei of these tumoral cells appear characteristically as enlarged with dispersed chromatin. The immunohistochemical reactions have been performed and it was observed that the tumoral cells exhibited positivity for synaptophysin, CD56, NSE, EMA, as well as a “dot-like” expression for CK20. These histopathological and immunohistochemical features were consistent with a diagnosis of MCC, stage pT3, based on the assessment of tumour size.
Conclusions: Sometimes, differentiating this tumour from other primary malignant neoplasms of the skin or even cutaneous metastases can be difficult. Immunohistochemistry remains the most important tool of diagnosis, especially for differentiating this neoplasm from metastatic neuroendocrine tumours that can affect the skin.

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Glomus Tumor of the Kidney: Case report

DOI: 10.2478/amma-2018-0018

Introduction: Glomus tumors are rare benign mesenchymal neoplasms accounting for only 2% of all types of soft tissue tumors. Commonly located in the peripheral soft tissues, they are most frequently encountered in the subungual areas of fingers and toes, and very rarely in visceral organs due to the absence of glomus bodies. To date, 22 cases of primary renal glomus tumors have been described in the literature, of which 17 benign, with no evidence of recurrence or metastasis, three cases of malignant glomus tumor, and two cases with uncertain malignant potential.
Case report: We report the 18th case of a benign glomus tumor of the kidney in a 49-year-old female patient, presenting the microscopic appearance (round, uniform cells with indistinct borders, scant finely granular eosinophilic cytoplasm, round nuclei lacking prominent nucleoli, arranged in solid sheets, accompanied by slit-like vascular spaces), the immunohistochemical profile (tumor cells showed immunoreactivity for smooth muscle actin, vimentin, as well as for CD34; they were negative for AE1/AE3, desmin, HMB-45, S-100 protein, renin, and chromogranin), and the differential diagnosis of this rare entity (juxtaglomerular tumor, angiomyolipoma, hemangioma, epithelioid leyomioma, solitary fibrous tumor, carcinoid tumor, and paraganglioma).
Conclusion: Primary renal glomus tumors are rare tumors that radiologically can mimic other mesenchymal renal neoplasm. Accurate diagnosis is based on the microscopic appearance and especially the characteristic immunophenotype.

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Comparative and Morphological Analysis of Patellar Tendon with the Native Anterior Cruciate Ligament (ACL): an Electron, Microscopic and Morphological Study

Background: Ligaments and tendons are similar in composition but differ in proportion and arrangement. Tendons are used as grafts for the ACL reconstruction. The microscopic structure of these tendons has not been sufficiently studied and compared to the native ACL.
Objective: To compare the structure of the patellar tendon graft with the structure of a normal anterior cruciate ligament.
Material and methods: A null hypothesis was declared stating that the anterior cruciate ligament should be histologically, morphologically and functionally different from the patellar tendon used for ACL reconstruction. We investigated similarities and dif-ferences of the structure of ACL and patellar tendon used as a graft tissue for ACL reconstruction. In this study, samples of patellar tendon, and the ACL were harvested from 18 patients during ACL reconstruction and analysed by light and electron microscopy, immunohistochemistry and morphometry.
Results: The thickness of the collagen fibrils, collagen organization and diameter, the fibril/interstitium ratio, density of fibroblasts and blood vessels, and distribution of the collagen type I, III and V fibrils were analyzed.
Discussions: The ACL had the highest concentration of type III and V collagen fibrils as well as elastic fibers.
Conclusion: The histological and ultrastructural appearance of the ACL differs from patellar tendon used as graft for ACL reconstruction.

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Semiautomated Image Analysis of High Contrast Tissue Areas Using Hue/Saturation/Brightness Based Color Filtering

Introduction: Quantification and morphological assessment of various tissue elements have numerous applications in fundamental and clinical research. Digital morphometry, in contrast to other morphologic methods, uses personal computers and specific software, to perform precise and highly reproducible results. Additionally, it delivers results in mathematical format. The aim of our study was to develop an open access digital morphometry method for measuring different parameters of various high contrast tissue elements and to elaborate a general work-around for digital morphometry study and data management.
Materials and methods: We used three different types of tissue samples and staining procedures: (1) Diffuse Large B-cell Lymphoma specimens, (2) various stage liver fibrosis specimens and (3) transversely sectioned skeletal muscle tissue to develop a digital morphometric analysis. Image analysis was performed using ImageJ software.
Results: We developed an intuitive and easy to use work-algorithm that fits generic demands. We split the algorithm into three phases, each requiring a different approach and workaround. Using the presented method we were able to quantify the proportion of CD34 positive areas in the DLBCL specimens, the vascularity of this type of lymphoma may be quantified; similarly, this method is optimal for determining the extension of fibrosis in liver specimens; and finally, morphometric analysis of striated muscle fibers was achieved.
Conclusions: We conclude that the use of ImageJ with semiautomatic color segmentation is a reliable and practical way of performing various morphometric measurements. In addition, we are confident that such methods of digital morphometry could have future applications in other areas of pathology and histology.

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The Evaluation of the Intramyocardial Coronary Microvasculature Subsequent to Heart Transplantation Using Microscopic and Immunohistochemical Methods

Introduction: This paper presents some histologic and immunohistochemical aspects of the intramyocardial microvascular network performed subsequently to cardiac transplantation in Romanian patients.
Material and method: We investigated a group of 30 heart transplant patients, aged between 12 and 58 at the time of transplantation, with an average age of 39 years, 23 male and 7 female patients. We studied in these patients the affection of the intramyocardial microvascular network subsequently to cardiac transplantation, using histologic and immunohistochemical standard methods. We followed the occurrence of foam cell arteritis at the level of large epicardial coronary arteries, as a direct sign of chronic rejection, lesions detected post-mortem at necropsy.
Results: In our study the most frequently detected microvascular lesions were the endothelial cell alterations, vascular wall thickening and severe perivascular fibrosis. Ischemia and reperfusion lesions with slight microvascular impairment were present in all patients in the first post-transplant biopsies (first 3–6 weeks). Acute cellular rejection developed in 6 patients in the middle and late period, in these cases we detected vasculitis lesions at the level of endomyocardial biopsies. Chronic rejection has affected three patients, who presented lesions at the level of large epicardial coronary arteries, as well as at the level of the small intramyocardial ones, such as wall thickening or perivascular fibrosis.
Conclusion: Subsequent to heart transplantation, small intramyocardial vessels are affected by immunological (rejection) or non-immunological factors (ischemia and fibrosis). Histologic and immunohistochemical study methods applied at the level of endomyocardial biopsies or post-mortem are useful for accurate assessment of small intramyocardial vessels and their involvement in the viability of the allograft.

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Multifocal Sarcomatoid Carcinoma of the Small Intestine

Sarcomatoid carcinomas (SCs) or carcinosarcomas are rare, biphasic tumors, with poor prognosis, only rarely located in the small and large intestine. The first treatment option of these tumors is surgical approach, adjuvant therapy showing no important role in the treatment protocol. We present the case of a 63 years old male patient, hospitalized in the Surgical Department II of the County Emergency Clinical Hospital Tîrgu Mureş with the diagnosis of small intestine tumor with jejunal localization. Microscopically, in hematoxylin-eosin (HE) staining, the tumor was consisting of two components, an epithelial and a mesenchymal one. From immunohistochemical point of view, tumor cells were strongly positive for cytokeratin AE1/AE3 as well as for vimentin. They were negative for epithelial membrane antigen (EMA), CD117, CD34, S100, chromogranin-A and synaptophisin. Based on the macroscopic and microscopic appearance, respectively the immunohistochemical feature of the tumor, the patient was diagnosed with multifocal sarcomatoid carcinoma of the small intestine.

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Expression of Cyclin D1 in Oral Leukoplakia Compared with Normal Mucosa, Benign and Malignant Tumors of the Oral Cavity

Introduction: Cyclin D1 is a rate-limiting controller of the G1 phase and the G1 to S transition of the cell cycle. It’s overexpression may cause disturbance in the normal cell cycle, which may lead to an increased proliferation and consecutive tumour formation. Our objective was to analyse the expression of Cyclin D1 in oral leukoplakia – the most frequent potentially malignant disorder of the oral mucosa – in comparison with normal mucosa, benign and malignant tumours of the oral cavity.
Material and methods: For this paper 51 consecutive cases of oral leukoplakia – surgically treated at the Oro-Maxillo-Facial Surgery Clinic from Târgu Mureş – and, for comparison 9 benign tumours and 27 oral squamous cell carcinomas (OSCCs) were selected. Eight normal mucosa samples were obtained from the peripheral regions of the benign tumours, excized with safe surgical margins. Histopathologically leukoplakias were graded as: with no, mild, moderate or severe dysplasia (G0-3), and OSCCs as: well-, moderately- or poorly-differentiated (G1-3). After immunohistochemical staining for Cyclin D1, statistical analysis was performed regarding the expression of the studied marker.
Results and conclusions: In our findings the difference between the expression of Cyclin D1 in normal mucosa, benign tumours and leukoplakias with no dysplasia was not significant, but the expression of this marker increased significantly with the increase of the grade of dysplasia in case of leukoplakias. A statistically significant difference was found also between leukoplakias and OSCCs, without any correlation regarding the histopathological grade of OSCCs.

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Correlation of APC and MLH1/MSH2 Expression in Colon Adenomas/Polyps

Background: Adenomatous polyposis coli (APC) gene is thought to play a key role in the majority of sporadic colorectal cancers developed through the chromosomal instability pathway. In 10–15% of CRC the defect of the mismatch repair genes (MLH1, MSH2), the microsatellite instability is the underlying mechanism for carcinogenesis. The aim of this study was the correlation of APC, MLH1 and MSH2 immunoexpression in different types of colon adenomas/polyps (A/P).
Materials and methods: We processed biopsies and surgical pieces of colon A/P and carcinoma developed in adenoma (CC). The APC, MLH1, MSH2 expression were graded, and used for establishing different immune phenotypes that have been compared by statistical tests. Results: The majority of tubular and tubulovillous adenomas have the MLH1+/MSH2+/APC+ immune phenotype, and the ratio of MLH1–/MSH2–/APC+ cases increases in case of hyperplastic polyps and serrated adenomas. A/P developing in the right colon and in patients below 40 years were more frequently MLH1–/MSH2–/APC+.
Conclusions: APC immunoexpression decreases in adenomas/polyps with dysplasia, and MLH1 and MSH2 expression is altered especially in hyperplastic polyps and serrated adenomas.

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Herlant’s Tetrachrome Staining, a Useful Tool for Pituitary Adenoma Diagnosis

DOI: 10.2478/amma-2013-0049

Introduction: The morphologic diagnosis of pituitary adenomas (PA) is based on immunohistochemistry (IHC). In Romania, IHC diagnosis of PA is restricted, all of the specific antibodies being very expensive. A histochemical staining, Herlant’s tetrachrome (HTCS), was described several years ago, but it was not widely used for diagnostic purposes because of technical difficulties. The aim of this paper is to bring into discussion this staining, to highlight its benefits, to improve the technical procedures and to establish a protocol, which combining both HTCS and IHC, facilitates the diagnosis of PA and, especially, substantially reduces the costs.
Methods: HTCS was performed using normal pituitary glands. The optimal time of staining and the optimal concentration of different solutions were established for each step of the staining.
Results: The improved technical procedure of HTCS is described. The staining features of all cellular types of the pituitary gland are depicted and illustrated: the chromophore cells, GH-secreting cells stained in orange, PRL-secreting cells in red-violet and ACTH-cells in dark blue, while cromophobe cells stained light blue. These staining features can be extrapolated to the diagnosis of PAs, as they consist of a proliferation of such cells.
Conclusion: HTCS’s benefit is in functional PAs: it can identify GH, PRL, ACTH and TSH-adenomas, according to the cell type staining. A two-step diagnostic protocol is proposed, allowing the use of two, maximum three antibodies, instead of six: first step HTCS, and second step IHC.

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Immunoexpression of Ki67 and p53 in the Dental Follicles of Impacted Teeth

DOI: 10.1515/amma-2015-0033

Aim. The purpose of this study was to evaluate the morphological aspects of dental follicles associated with impacted teeth and the immunoexpression of Ki 67 and p53, in the remaining epithelium from impacted third molars and canines. Another aspect was to identify the transformation of the remaining epithelium within the odontogenic lesions.
Material and method. We included in the study a number of 100 dental follicles, of which only 62 met the inclusion criteria. The immunohistochemical reactions were carried out in the Immunohistochemistry Lab at the Department of Histology of the University of Medicine and Pharmacy of Târgu Mureş. We counted 100 cells from the remaining epithelial islands from which we determined the percentage of labeled cells for both markers. After this all data were subjected to a statistical analysis.
Results. Out of the 62 specimens 44 were from females and 28 from males. Positive results were obtained for the two markers but not for all cases. We have also found a positive correlation regarding the immunolabeling of the two markers (p=0.002 in canines, p=0.0001 in molars). Median values for ki67 were statistically significantly higher than the values for p53 for both types of dental follicles.
Conclusions. Both markers were expressed in the remaining epithelial islands. The stronger expression of Ki67 in the follicles of impacted molars can demonstrate the
higher frequency of odontogenic cysts in this area.

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