[Adenocarcinoma of nonpigmented ciliary body epithelium (clinical cases)]

The article presents two clinical cases of adenocarcinoma of nonpigmented epithelium of the ciliary body, which is a very rare malignant tumor of the organ of vision with distinctive features. Surgical treatment is necessary to verify this tumor and assess the degree of its aggressiveness in terms of the prognosis of the disease, with subsequent pathomorphological and immunohistochemical studies. The article also discusses the epidemiological aspects, morphological features, clinical manifestations of this pathological condition, as well as possible treatment options and features of follow-up monitoring of this group of patients.

Development and Evaluation of a Leukemia Diagnosis System Using Deep Learning in Real Clinical Scenarios

Leukemia is the most common malignancy affecting children. The morphologic analysis of bone marrow smears is an important initial step for diagnosis. Recent publications demonstrated that artificial intelligence is able to classify blood cells but a long way from clinical use. A total of 1,732 bone marrow images were used for the training of a convolutional neural network (CNN). New techniques of deep learning were integrated and an end-to-end leukemia diagnosis system was developed by using raw images without pre-processing. The system creatively imitated the workflow of a hematologist by detecting and excluding uncountable and crushed cells, then classifying and counting the remain cells to make a diagnosis. The performance of the CNN in classifying WBCs achieved an accuracy of 82.93%, precision of 86.07% and F1 score of 82.02%. And the performance in diagnosing acute lymphoid leukemia achieved an accuracy of 89%, sensitivity of 86% and specificity of 95%. The system also performs well at detecting the bone marrow metastasis of lymphoma and neuroblastoma, achieving an average accuracy of 82.93%. This is the first study which included a wider variety of cell types in leukemia diagnosis, and achieved a relatively high performance in real clinical scenarios.

Morphological and Molecular Diagnosis of Necator americanus and Ancylostoma ceylanicum Recovered from Villagers in Northern Cambodia

Human hookworm infections caused by adult Ancylostoma spp. and Necator americanus are one of the most important tropical diseases. We performed a survey of intestinal helminths using the Kato-Katz fecal examination technique targeting 1,156 villagers residing in 2 northern provinces (Preah Vihear and Stung Treng) of Cambodia in 2018. The results revealed a high overall egg positive rate of intestinal helminths (61.9%), and the egg positive rate of hookworms was 11.6%. Nine of the hookworm egg positive cases in Preah Vihear Province were treated with 5–10 mg/kg pyrantel pamoate followed by purging with magnesium salts, and a total of 65 adult hookworms were expelled in diarrheic stools. The adult hookworms were analyzed morphologically and molecularly to confirm the species. The morphologies of the buccal cavity and dorsal rays on the costa were observed with a light microscope, and the nucleotide sequences of mitochondrial cytochrome c oxidase subunit 1 (cox1) gene were analyzed. The majority of the hookworm adults (90.7%) were N. americanus, whereas the remaining 9.3% were Ancylostoma ceylanicum, a rare hookworm species infecting humans. The results revealed a high prevalence of hookworm infections among people in a northern part of Cambodia, suggesting the necessity of a sustained survey combined with control measures against hookworm infections.

[Limitation of possibilities of cytological diagnosis of papillary thyroid cancer at the pre-surgery stage]

AIM OF STUDY

A comparison of papillary cancer variants diagnosed on the basis of cytological findings of pre-surgery puncture biopsies with a histological variant of papillary cancer.

MATERIALS AND METHODS

The findings of two experts specializing in cytological diagnostics of thyroid nodules that diagnosed a possible variant of papillary cancer were compared with histological findings based on the study of material from surgically removed neoplasms.

RESULTS

It was shown that the cytological examination at the pre-surgery stage has significant limitations in diagnosing the histological variant of the tumor, despite high sensitivity of method in diagnosing papillary cancer in general. The variability of results of the cytological determination of papillary cancer variant between the two experts was not so significant, it concerned small fluctuations in the frequency of the diagnosing og normal, follicular, cystic and Uortino-like variants. Based on the data of cytological method, it is not possible to establish the encapsulated variant and papillary microcarcinoma; there are limitations in the diagnosis of follicular and high tumor cell variants.

CONCLUSIONS

Currently, the advisability of the recommendation to determine the variant of papillary cancer using the cytological method is questionable. However, this does not mean that it is necessary to stop the search for reliable cellular and molecular genetic characteristics of clinically aggressive variants of papillary cancer.

[Pathological anatomy of tuberculosis in the presence of human immunodeficiency virus infection]

Tuberculosis occupies a leading position among secondary infections in the structure of mortality in HIV-positive patients. Moreover, the concurrence of these diseases frequently makes a morphological diagnosis most difficult due to the atypical course of tuberculosis (TB) in the presence of immunosuppression.

AIM

to assess the clinical and morphological characteristics of concurrent TB/HIV infection.

MATERIAL AND METHODS

An autopsy material obtained from the S.P. Botkin Clinical Infectious Diseases Hospital (CIDH) in 2018 was analyzed. Eight samples stained with hematoxylin and eosin, Ziehl-Neelsen carbol-fuchsin, auramine-rhodamine were thoroughly examined, followed by fluorescent microscopy; an immunohistochemical (IHC) study was performed.

RESULTS AND DISCUSSION

736 autopsies made at the S.P. Botkin CIDH in 2018 revealed 357 deaths from HIV infection; 86 (24%) cases of which were caused by concurrent HIV/TB infection. All the cases showed an extremely diverse and heterogeneous pattern that considerably differed from that of classical granulomatous inflammation in tuberculosis. Ziehl-Neelsen staining could demonstrate single clusters of acid-resistant bacteria with a total of not more than 1000 in the specimen of predominantly rod-shaped bacteria. Auramine-rhodamine staining revealed focal clusters of mycobacteria with a total of 1000 to 2000 in the specimen of predominantly rod-shaped and coccoid bacteria. An IHC study identified clusters of mycobacteria with a total of more than 2000 in the sample, which were characterized by a moderate variety of shapes: rods, cocci, granules, clavate, and branched ones. Mycobacteria were present extracellularly in all the studied cases.

CONCLUSION

Tuberculosis holds the most important place in the pattern of causes of death in HIV infection, accounting for 24%. The lifetime diagnosis of tuberculosis remains not entirely satisfactory. The alterative component of inflammation more often predominates, although without completely losing the ability to form granulomas. The concurrence of different morphological forms of tuberculosis makes it highly desirable to clarify and/or supplement the existing classifications. None of the methods used to detect Mycobacterium tuberculosis in the tissues could reveal the intracellular localization of the pathogen. Most mycobacteria had a typical rod-shaped morphology.

[Thyroid follicular cell tumors: cytohistological comparisons in the context of the new international classification]

OBJECTIVE

To carry out a correlation retrospective analysis of the histological and cytological findings of follicular cell neoplasms over a two-year period after the publication of the new WHO classification of thyroid tumors (2017), which identifies a category of follicular tumors of uncertain malignant potential (T-UMP).

MATERIAL AND METHODS

The investigators of the Clinic, National Medical Research Center for Endocrinology, Ministry of Health of Russia, made a cytohistological comparison of morphological findings, by using the material of surgically removed follicular cell neoplasms.

RESULTS

The investigation showed the lack of unreasonably common usage of the histological classification category of T-UMP (3.08%). Non-invasive follicular neoplasm with papillary-like nuclei predominantly diagnosed in the T-UMP category was more frequently (83.3) assigned to Diagnostic Category IV of the 2017 Bethesda system for the cytological diagnosis of thyroid tumors. Cytology showed the highest (98.1%) sensitivity, including classic (97.8%), encapsulated (100%), and follicular (97.7%) options in diagnosing papillary cancer, being substantially inferior in diagnosing follicular and Hürthle cell neoplasms, in which diagnostic category IV category was more frequently established for adenomas (81.4%) and carcinomas (69.5%).

CONCLUSION

The morphological differential diagnosis of follicular cell neoplasms seems to be a relevant problem.

[The informative value of various methods for identifying acid-fast bacilli in relation to the degree of tuberculosis process activity]

Carbol fuchsin (Ziehl-Neelsen) staining is a major method used since the late nineteenth century to detect Mycobacterium tuberculosis in the tissues. At the same time, the number of mycobacteria does not frequently show a clinical and morphological correspondence to the activity of the infectious process.

OBJECTIVE

To reveal the morphological characteristics of Mycobacterium tuberculosis in patients with long-lasting tuberculosis.

MATERIAL AND METHODS

Twenty-four autopsies of verified fibrous-cavernous tuberculosis were examined. Paraffin sections were stained with hematoxylin and eosin, carbol fuchsin (Ziehl-Neelsen), or auramine-rhodamine (followed by luminescence microscopic examination); an immunohistochemical (IHC) study with serum to PAV (Protein antigen B) was conducted.

RESULTS AND DISCUSSION

The changes characteristic of progressive tuberculosis were revealed in all the cases. The Ziehl-Neelsen staining revealed isolated clusters of acid-fast bacilli (a total of 1,000 in less than 10 fields of view). When stained with auramine-rhodamine, the number of found mycobacteria proved to be significantly larger (a total of 1,000 to 10,000 in 10-50 fields of view) and that was greatest in the IHC study (a total of over 10,000 in more than 50 fields of view). At the same type, all types of studies revealed that the localization of mycobacteria was exclusively extracellular. The Ziehl-Neelsen staining indicated that the proportion of typical bacilli was much higher (85-95%; mean 88.13±2.14) than that (50-85%; mean 64.38±4.24%) identified when stained with auramine-rhodamine and even more significantly more than that (50-70%; mean 57.29±2.78%) detected during the IHC study. The indicators were equally different for the atypical morphological forms of mycobacteria identified in minimal quantities by the Ziehl-Nielsen staining and in large quantities by fluorescence and IHC studies.

CONCLUSION

There is evidence for the ability of mycobacteria to have morphological polymorphism and for the need to clarify the pathogenesis of tuberculosis.

The Usefulness of Muscle Biopsy in Initial Diagnostic Evaluation of Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-Like Episodes

PURPOSE

The disease entity mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) is characterized by an early onset of stroke-like episodes. MELAS is the most dominant subtype of mitochondrial disease. Molecular genetic testing is important in the diagnosis of MELAS. The mitochondrial DNA (mtDNA) 3243A>G mutation is found in 80% of MELAS patients. Nevertheless, molecular analysis alone may be insufficient to diagnose MELAS because of mtDNA heteroplasmy. This study aimed to evaluate whether muscle biopsy is useful in MELAS patients as an initial diagnostic evaluation method.

MATERIALS AND METHODS

The medical records of patients who were diagnosed with MELAS at the Department of Pediatrics of Gangnam Severance Hospital between January 2006 and January 2017 were reviewed. The study population included 12 patients. They were divided into two subgroups according to whether the results of muscle pathology were in accordance with mitochondrial diseases. Clinical variables, diagnostic evaluations, and clinical outcomes were compared between the two groups.

RESULTS

Of the 12 patients, seven were muscle pathology-positive for mitochondrial disease. No statistically significant difference in clinical data was observed between the groups that were muscle pathology-positive and muscle pathology-negative for mtDNA 3243A>G mutation. Additionally, the patients with weakness as the initial symptom were all muscle pathology-positive.

CONCLUSION

The usefulness of muscle biopsy appears to be limited to an initial confirmative diagnostic evaluation of MELAS. Muscle biopsy can provide some information in MELAS patients with weakness not confirmed by genetic testing.

[Scleromyxedema as a systemic disease of glycosaminoglycan accumulation]

Scleromyxedema is a rare mucinosis with a primary skin lesion due to diffuse mucin deposition, sclerosis, and lichenoid eruptions in the absence of hypothyroidism. The paper describes scleromyxedema cases and gives recommendations for the histological diagnosis of the disease by histochemical reactions to detect acid and neutral glycosaminoglycans.

[Is scleromyxedema a skin problem or systemic pathological process?]

Scleromyxedema is regarded as a rare cutaneous mucinosis from a group of lichen myxedematosus characterized by diffuse mucin deposition, sclerosis, and lichenoid eruptions in the absence of thyroid disease. The paper discusses the pathogenesis of the disease and histological changes in tissues. It underlines the need for using histochemical tests to identify acidic and neutral glycosaminoglycans and gives a differential diagnosis of this disease.

Electron microscopy for rapid diagnosis of infectious agents in emergent situations

Diagnostic electron microscopy has two advantages over enzyme-linked immunosorbent assay and nucleic acid amplification tests. After a simple and fast negative stain preparation, the undirected, "open view" of electron microscopy allows rapid morphologic identification and differential diagnosis of different agents contained in the specimen. Details for efficient sample collection, preparation, and particle enrichment are given. Applications of diagnostic electron microscopy in clinically or epidemiologically critical situations as well as in bioterrorist events are discussed. Electron microscopy can be applied to many body samples and can also hasten routine cell culture diagnosis. To exploit the potential of diagnostic electron microscopy fully, it should be quality controlled, applied as a frontline method, and be coordinated and run in parallel with other diagnostic techniques.