The purpose of the review:to summarize the main data of the literature and our own accumulated practical experience of everyday diagnosis of inflammatory bowel diseases (IBD) to better represent the morphological features and histological conclusions.Key points.The microscopic picture of IBD is often represented by a combination of basic histological characteristics that can be detected in other diseases and only in rare cases can be considered pathognomonic. No single histological feature can be used in isolation to diagnose ulcerative colitis or Crohn’s disease. Diagnostic accuracy is improved if several signs are taken into account at once, if changes within one or more parts of the intestine are analyzed, it is necessary to compare the identified changes with the clinical picture of the disease.Conclusion.The presented stages of the morphological study of biopsy specimens in patients with IBD and the exact characteristics of the detected changes will help to increase the diagnostic value of the study of ileo- and colonobiopsies, as well as improve mutual understanding between gastroenterologists and pathologists and, as a result of interaction between specialists, will increase the accuracy of the diagnosis.

The histological activity of the bowel inflammation is an extremely important morphological criterion that is encountered in the diagnosis of colitis. However, the determining of its degree is subjective and still does not have a generally accepted principle of gradation. The article describes the most common scale-schemes for assessing the severity of colitis, that include the degree of microscopic changes. The results of the analysis of the of histological activity degree on the material of colonobioptates in colitis of various etiologies (467 patients) are presented. It has been shown that the Geboes scale of ulcerative colitis can be used to assess histological activity in all forms of colitis. The histological features of inflammation should be reflected in the pathological diagnosis and are essential for clinical decision making. This index allows for a comparative analysis of clinical, endoscopic and morphological parameters and better control of the patient's condition during the treatment.

OBJECTIVE:To determine immunohistochemical features of IgG4-related disease in patients with inflammatory bowel diseases (IBD).MATERIAL AND METHODS:Immunohistochemical testing of colonic biopsy material from 35 patients with IBD (24 cases of ulcerative colitis and 11 cases of Crohn's disease) was carried out using IgG, IgG4 and CD138 antibodies. The number of IgG4- and CD138-positive cells was counted in high power field of microscope (×400). Patient selection was random.RESULTS:IgG4-positive cells were detected in the colonic mucosa of 5 patients with ulcerative colitis. The age of the patients ranged from 24 to 47 years. Two patients had a total, and three had a left-sided lesion of the colon. The anamnesis of the disease ranged from 3 to 13 years. The number of positively stained cells in the reaction with the antibody to IgG4 varied from 2 to 50 in high power field of microscope. We were able to detect over 10 IgG4-positive cells in 3 females aged 28, 30 and 31 years with a long history of ulcerative colitis (5, 4 and 3 years, respectively). Two patients had a total lesion of the colon, all three had an exacerbation of the disease, and a morphological study revealed chronic diffuse active erosive colitis. A high degree of histological activity and pronounced diffuse basal plasmacytosis were noted. In one of the cases, the infiltrate captured the muscular lamina of the mucosa and areas of the submucosa.CONCLUSIONS:IgG4-positive cells in the inflammatory infiltrate, including those with an excess of more than 10 in the field of view of the microscope at high magnification, can be observed in patients with ulcerative colitis with severe and prolonged course of the disease. To classify this colitis as a manifestation of an IgG4-related disease, the results of immunohistochemical studies alone are not enough. It is required to accumulate a larger number of observations, as well as to search for other diagnostic criteria for an IgG4-related disease in these patients.

Background: Primary hyperparathyroidism (PHPT) is the third most common endocrine disease, after diabetes mellitus and thyroid gland disorders. Surgical removal of the hyperfunctioning parathyroid glands is the only radical treatment. Various methods of preoperative imaging and intraoperative navigation are developed. Planar scintigraphy with 99mTc-MIBI is used for visualization and it is the most frequently performed radionuclide study in PHPT, while it has a relatively low sensitivity and specificity. SPECT/CT can reduce false-negative and false-positive results, and combines the advantages of radionuclide diagnostic methods and computed tomography. However, the factors that prevent the accumulation of 99mTc-MIBI in patients with PHPT are not clear enough. Aim: To identify the factors associated with the degree of accumulation (uptake rate) of 99mTc-MIBI in the parathyroid glands during planar scintigraphy and SPECT/CT. Materials and methods: The cross-sectional comparative study included 186 patients with PHPT who underwent planar scintigraphy and SPECT/CT for topical diagnosis of parathyroid glands and minimally invasive parathyroidectomy (MIP) followed by histological and immunohistochemical examination of parathyroid glands. The patients were divided into 3 groups depending on the accumulation of 99mTc-MIBI. The accumulation of 99mTc-MIBI was assessed by the expert as low-, moderate-, and high-intensity. Results: The association between the volume of the parathyroid glands on ultrasound and the intensity of the capture of the radiopharmaceutical was revealed, and 80% of low uptake is observed if volume is less than 0,215 cm3 (it corresponds to the linear size of the parathyroid gland 5 mm). Next factor that complicate the interpretation of the results of planar scintigraphy and SPECT/CT in patients with PHPT is thyroid diseases. The associations of the level of PTH, calcium in the blood, the localization and cellular composition of the parathyroid glands, the index of proliferative activity (Ki67), the expression of PTH, P-glycoprotein, cyclin D1 in the PTG tissue with the intensity of 99mTc-MIBI accumulation were not found. Conclusions: The main factor that positively associates with the degree of 99mTc-MIBI accumulation with planar scintigraphy and SPECT / CT is the volume of the parathyroid glands according to ultrasound data. Comorbidity of the thyroid gland has tendency to be associated with a negative result of radionuclide diagnostics, thus based on the ultrasound data of the thyroid and parathyroid glands it is possible to choose the second preferable method of imaging (SPECT/CT or contrast enhanced CT).

Introduction. Morphological diagnosis of inflammatory bowel diseases (IBDs) based on endoscopic biopsies remains a rather challenging task and does not always allow the pathologist to make the final conclusion. Difficulties arise due to the absence of a classical morphological picture in biopsy specimens as well as the lack of clinical and laboratory data. These issues may lead to an incorrect interpretation of the detected pathological changes and an erroneous conclusion. The aim of the study was to assess the quality of biopsy diagnosis of IBDs using Internet diagnostic tools, namely, the digitalized histological slides. Materials and methods. We created an Internet platform, which contained 100 scanned images of histologi-cal slides from 70 patients with suspected IBD. Based on our own practical experience and guidelines of international European and British societies of pathology, we arranged a survey. The diagnosis was made on the combined clinical and morphological approach, considering also a complex of clinical, laboratory, endoscopic, and morphological data. The first stage of the survey was anonymous and included a list of 25 questions. Ten pathologists, who agreed to take part in the study, completed the questionnaire. After statistical processing, the results were assessed using a Fleiss' kappa criterion. Results. The comparative analysis of morphological study showed that the participants were able to diagnose accurately only 71% of ulcerative colitis cases and 63% of Crohn’s disease cases. At the same time, the agreement coefficient demonstrated satisfactory values: the Fleiss' kappa was 0.34 and 0.25, respectively. In some cases, the participants found it difficult to perform a differential diagnosis between IBD and other forms of colitis and were not always capable of distinguishing ulcerative colitis from Crohn’s disease. A few of the individual criteria, on which the diagnosis is based, rarely reached agreement above a kappa of 0.5. The participants’ agreement was considered more often as “weak” and “satisfactory”. This is largely due to the fact that we did not discuss the exact criteria for the proposed parameters and that these parameters were divided into four degrees of severity from 0 to 3. Conclusion. The results showed the current discrepancies in the assessment of biopsies in patients with suspected IBD. The developed Internet platform provides additional significant opportunities to improve the quality of morphological diagnosis in ileal and colon biopsies by means of refining the criteria and their assessment in the final diagnosis statement. Keywords: inflammatory bowel disease, colitis, digital pathology

Background: Aldosterone-producing adrenocortical adenoma (APA) is responsible for the majority of cases clinically diagnosed as primary aldosteronism. Aldosterone synthase (CYP11B2) is one of the enzymes that play essential roles in aldosterone synthesis and is involved in the pathogenesis of primary aldosteronism. Recent studies have demonstrated that various factors influence the expression and function of CYP11B2 in APA. In particular, somatic mutations, such as gain-of-function and loss-of-function mutations have been identified in several genes, each of which encodes a pivotal protein that affects the calcium signaling pathway, the expression of CYP11B2, and aldosterone production. On the other hand, CYP11B2 also catalyzes the conversion of cortisol to 18-hydroxycortisol and subsequently converts 18-hydroxycortisol to 18-oxocortisol. The article also discusses the clinical significance of 18-oxocortisol, an important biomarker for the diagnosis of primary aldosteronism. Somatic mutations in aldosterone-driver genes are strongly associated with CYP11B2 expression and have been only detected in the CYP11B2-positive tumor area, that indicating heterogeneous expression of CYP11B2 in tumor.Aim: to assess the functional heterogeneity of adrenal tumors in primary aldosteronismMaterials and methods: Retrospective evaluation adrenal tumors from patients with primary aldosteronism (n=20). According to CT unilateral macrohyperplasia was detected in 19 patients (95% of total), all of them were confirmed to have unilateral hyperproduction of aldosterone according to AVS. Selected tumors werestained with anty-CYP11B2 antibody. We evaluated the CYP11B2 expression in the adenoma and in the adjacent adrenal cortex.Results: Immunohistochemistry studies of the resected adrenals from 20 patients with PA operated due to unilateral production of aldosterone using CYP11B2 staining showed that 10 of those with an adenoma on CT scanning showed CYP11B2 staining in the adenoma. Furthermore, 5 cases of an unilateral adenoma, showed CYP11B2 staining in the adjacent adrenal cortex and an absence of staining for CYP11B2 in the adenoma. 5 cases showed CYP11B2 expression is heterogeneously immunolocalized throughout the tumor area.Conclusion: Thus, the functional heterogeneity of adrenal tumors in primary aldosteronism has been proven. It is necessary to compare the data of immunohistochemical studies on the expression of CYP11B2 with the indicators of the level of 18-hydroxycortisol, 18-oxocortisol.

Adrenocortical cancer (ACC) is a rare endocrine malignancy of the adrenal cortex, which has an unfavorable prognosis and extremely aggressive clinical behavior in most cases. Nevertheless, cases of a more favorable disease course with late metastasis and slow progression have been described. In 2017, the International Agency for Research on Cancer (IARC) and the World Health Organization (WHO) in the 4th edition of the Classification of Tumors of the Endocrine Organs identified histological variants of ACC, such as classical, oncocytic, myxoid, and sarcomatoid ones, indicating the morphological heterogeneity of this tumor.OBJECTIVE:To provide a detailed description of the morphological variants of ACC with an emphasis on their histological characteristics and the expression of immunohistochemical markers.MATERIALS AND METHODS:A total of 75 cases of ACC were analyzed in the adult population diagnosed as having the morphological variants in accordance with the International Histological Classification of Adrenal Tumors (WHO, 2017). Monoclonal antibodies to SF1, Inhibin A, Melan A, Ki-67, p53, and antimitochondrial antibodies were used for immunohistochemical diagnosis.RESULTS:The classic, oncocytic, and myxoid subtypes of ACC were found in 51 (68%), 15 (20%), and 9 (12%) cases, respectively. The functional activity of the tumors was observed in 43% (n=18) in the classic variant of ACC; moreover, the clinical picture was manifested by the symptoms of hypercorticism (38%) and virilization (5%). There were no significant differences in hormonal activity between different morphological variants. The characteristics of the above histological variants of the tumor was determined with a description of growth patterns that can improve the diagnosis of ACC. The diagnosis of ACC can be confirmed by an immunohistochemical study; the required minimum panel of markers should include SF1, Melan A, and Inhibin A. The Ki-67 proliferative activity index showed significant differences (p=0.0056) when it was determined in the morphological variants of ACC.CONCLUSION:Despite the determination of a minimal immunohistochemical panel to confirm the diagnosis of ACC, it is important to remember that each histological variant may be characterized by the different expression of immunohistochemical markers. The identification of morphological variants of ACC and the use of specific, sensitive, and prognostically significant immunohistochemical markers will allow clinicians and pathologists to more accurately judge the biological properties of this tumor and the clinical course of the disease.

OBJECTIVE:To revise the existing criteria to improve the definition of chronic colitis stages in inflammatory bowel diseases (IBDs).MATERIAL AND METHODS:A total of 100 cases of IBDs (ulcerative colitis (n=70) and Crohn's disease (n=30) diagnosed in 2017 to 2019 were examined. Thirty patients with colitis were selected for a comparison group, who were assigned to an infective colitis group or a drug-induced colitis one at the final diagnosis.RESULTS:The sequence of chronic colitis stages was defined from Stage 1 (early changes) to Stage 3, which are characterized by progressive mucosal structural rearrangement. Mainly at Stage 3 that characterizes the final stage of structural rearrangement in the mucous membrane, where dysplastic changes (the onset of tumor transformation) are detected.CONCLUSION:For the diagnosis of chronic colitis in IBD, it is mandatory to detect mucosal structural rearrangement. Stages 1 and 2 are characterized by early structural changes in the mucous membrane, whereas the process becomes irreversible at Stage 3. The identification of colitis stages is of diagnostic and, undoubtedly, prognostic value.

Functioning gonadotroph adenomas are rare pituitary tumors secreting one or two gonadotropins (follicle-stimulating hormone (FSH) and/or luteinizing hormone (LH)), which are hormonally active. In the majority of cases, gonadotroph tumors are endocrinologically “silent” and make up more than a half of non-functioning pituitary adenomas. In this article we describe a rare clinical case of LH/FSH-secreting pituitary macroadenoma with bitemporal hemianopsia in a 62-year-old man. The patient underwent transnasal transsphenoidal adenomectomy, leading to remission. The distinctive feature of this case is the presence of secondary erythrocytosis due to endogenous hyperandrogenism, which required several blood exfusions to normaliza the level of hematocrit before surgery. It is noteworthy that clinical signs of erythrocytosis were present long before visual impairment. This clinical case demonstrates difficulties in the early diagnosis of functioning gonadotroph adenomas.

The diagnosis was made on the combined clinical and morphological approach, considering also a complex of clinical, laboratory, endoscopic, and morphological data. The first stage of the survey was anonymous and included a list of 25 questions. Ten pathologists, who agreed to take part in the study, completed the questionnaire. After statistical processing, the results were assessed using a Fleiss' kappa criterion. Results. The comparative analysis of morphological study showed that the participants were able to diagnose accurately only 71% of ulcerative colitis cases and 63% of Crohn’s disease cases. At the same time, the agreement coefficient demonstrated satisfactory values: the Fleiss' kappa was 0.34 and 0.25, respectively. In some cases, the participants found it difficult to perform a differential diagnosis between IBD and other forms of colitis and were not always capable of distinguishing ulcerative colitis from Crohn’s disease. A few of the individual criteria, on which the diagnosis is based, rarely reached agreement above a kappa of 0.5. The participants’ agreement was considered more often as “weak” and “satisfactory”. This is largely due to the fact that we did not discuss the exact criteria for the proposed parameters and that these parameters were divided into four degrees of severity from 0 to 3. Conclusion. The results showed the current discrepancies in the assessment of biopsies in patients with suspected IBD. The developed Internet platform provides additional significant opportunities to improve the quality of morphological diagnosis in ileal and colon biopsies by means of refining the criteria and their assessment in the final diagnosis statement.

Functioning gonadotroph adenomas are rare pituitary tumors secreting one or two gonadotropins (follicle-stimulating hormone (FSH) and/or luteinizing hormone (LH)), which are hormonally active. In the majority of cases, gonadotroph tumors are endocrinologically “silent” and make up more than a half of non-functioning pituitary adenomas. In this article we describe a rare clinical case of LH/FSH-secreting pituitary macroadenoma with bitemporal hemianopsia in a 62-year-old man. The patient underwent transnasal transsphenoidal adenomectomy, leading to remission. The distinctive feature of this case is the presence of secondary erythrocytosis due to endogenous hyperandrogenism, which required several blood exfusions to normaliza the level of hematocrit before surgery. It is noteworthy that clinical signs of erythrocytosis were present long before visual impairment. This clinical case demonstrates difficulties in the early diagnosis of functioning gonadotroph adenomas.

Insulinoma is the most common functioning pancreatic neuroendocrine tumor. The review examines the currently used immunohistochemical and circulating markers for its diagnosis, and discusses the sensitivity and specificity of these parameters. At the same time, the relevance of searching for new biochemical indicators of the presence of insulinoma and its characteristics, as well as studying the mechanisms of tumor growth and hormonal hypersecretion is emphasized. One of the primary methods for solving these problems is immunohistochemical testing with the determination of circulating markers. The results of recent studies of alternative secretory products, in particular, cocaine - and amphetamine - regulated transcript (CART), chromogranin B, and neuroendocrine secretory protein 55 (NESP55) are presented. In addition, the question of expression of various receptors in the insulinoma tissue is considered, including in the context of determining molecular targets for its visualization or radiotherapy. In particular, the expression of receptors for glucagon-like peptide 1 in the tumor tissue is characterized. The possible role of melatonin receptors MT1 (MTNR1a) and MT2 (MTNR1b) in the pathogenesis of insulinoma is clarified. The article also discusses the possible use of tumor protein D52 (TPD52) as a new predictive biomarker for the differential diagnosis of benign and malignant insulinoma.

Bilateral macronodular adrenal hyperplasia (BMAH) is a rare cause of Cushing's syndrome. In this case cortisol production can be regulated by both genetic factors and various molecular mechanisms. The presence of aberrant or overexpression of eutopic receptors on the membrane of adrenal cortex may lead to activation of cAMP/PKA signaling pathways and consequently, pathological stimulation of steroidogenesis. Since proving the effectiveness of unilateral adrenalectomy in BMAH by achievement of stable remission, preoperative clinical and laboratory tests (ligand-induced tests) are no longer of relevant. Nevertheless, in the absence of normalization of the level of cortisol in the postoperative period or its recurrence, subsequent specific targeted medical options can be offered only if expression/hyperexpression predominance of one or another receptor. Their detection becomes possible using more reliable diagnostic methods such as polymerase chain reaction (PCR) and immunohistochemical studies (IHC) than clinical laboratory tests. At the moment, PCR has gained a wider application. This article summarizes data on the use of immunohistochemical study in BMAH.

The article describes the clinical case of diagnosing and choosing the tactics for treating ovarian adrenal rest tumors (OART) in a patient with a salt-wasting form of congenital adrenal hyperplasia (CAH). There are only several clinical cases descriptions of OART in the world literature. At present, the tactics of observation and treatment of the ovarian adrenal rest tumors has not been developed. In each case, individual tactics are chosen. The main predisposing factor to the occurrence of OART is considered to be long periods of decompensation of CAH. ACTH stimulates the hyperplasia and hypertrophy of the residual adrenal tissue in the ovaries and secondary tumors develop. The instrumental methods that allow to diagnose OART include ultrasound, MRI of the pelvic organs, PET with 18FDG. The tactics of treating OART, in contrast to the testicular adrenal rest tumors in men (TART), according to world literature are mainly surgical. Organ-preserving operations were performed, as well as the removal of tumors along with the ovary. Cases of a combination of adenocarcinoma and CAH are also described. Each new case of OART is unique and with the accumulation of international experience, a consensus will be developed.

Cushing’s syndrome accounts for approximately 20–30% of endogenous hypercortisolism cases, and adrenal involvement can be either unilateral or bilateral. Cushing’s syndrome due to bilateral adrenal tumors is extremely rare. Adrenal oncocytomas are another rare cause of endogenous hypercortisolism: about 13 cases are described in the literature. Oncocytomas are rare epithelial neoplasms, characterized by abnormally excessive accumulation of defective mitochondria in the cytoplasm of cells, and make up 1.8% of all adrenal neoplasms. We describe a 58-year old patient with Cushing’s syndrome and bilateral adrenal tumors. Multispiral computed tomography of the adrenals showed signs suspicious of lipid-poor atypical adenomas or malignant tumors. Surgical treatment was the method of choice, and the larger tumor was excised first. Due to the absence of remission of endogenous hypercortisolism the excision of the second tumor was performed. Morphological and immunohistochemical examination confirmed the diagnosis of bilateral oncocytic adrenocortical tumors with uncertain malignant potential. Cases of bilateral hormone-producing adrenal oncocytomas have not been described in the literature.

Bilateral macronodular adrenal hyperplasia (BMAH) is a rare cause of Cushing’s syndrome. In this case cortisol production can be regulated by both genetic factors and various molecular mechanisms. The presence of aberrant or overexpression of eutopic receptors on the membrane of adrenal cortex may lead to activation of cAMP/PKA signaling pathways and consequently, pathological stimulation of steroidogenesis. Since proving the effectiveness of unilateral adrenalectomy in BMAH by achievement of stable remission, preoperative clinical and laboratory tests (ligand-induced tests) are no longer of relevant. Nevertheless, in the absence of normalization of the level of cortisol in the postoperative period or its recurrence, subsequent specific targeted medical options can be offered only if expression/hyperexpression predominance of one or another receptor. Their detection becomes possible using more reliable diagnostic methods such as polymerase chain reaction (PCR) and immunohistochemical studies (IHC) than clinical laboratory tests. At the moment, PCR has gained a wider application. This article summarizes data on the use of immunohistochemical study in BMAH.

Papillary carcinoma is the most commonly diagnosed form of well-differentiated thyroid cancer that is generally characterized by a favorable prognosis. However, a number of relatively rare variants of this tumor, such as papillary carcinoma of high cells, papillary carcinoma of columnar cells, a diffuse sclerosing variant and recently described cancer of shoe nail cell type, are characterized by a less favorable clinical course, a high frequency of distant metastasis, and relatively low overall and relapse-free survival rates. In this connection, it is important to recognize these options at the stage of a primary morphological study. This review of the literature considers the morphological, clinical and molecular genetic features of the above variants of papillary thyroid carcinoma.

Studies of the last decade have demonstrated that the morphological and immunophenotypic patterns of adrenocortical carcinoma (ACC) have a high heterogeneity in both the occurrence of various tumors and the development of a solitary tumor. Carcinogenesis of ACC, like most neoplastic processes, is associated with mutations in at least 15 driver genes, with a wide range of chromosomal aberrations, epigenomic changes, and alterations of the microRNA profile. According to the literature, isolated genetic damage is also insufficient for the manifestation of the malignant phenotype of adrenocortical cells. Knudson's two-hit hypothesis is implemented in at least germline mutations: the development of ACC requires a second genetic event occurring in somatic cells, which leads to inactivation of the second allele of the gene. ACC is an extremely heterogeneous disease, which determines the complexity of differential diagnosis with benign adrenocortical tumors and that of prediction of the clinical course. Another no less important issue is the lack of valid predictors for the efficacy of mitotane, the use of which may be associated with severe adverse effects.