Vol 4, No 1-2 (2021)

Background. The technique of cell blocks is an important step in the development of the morphological method, which effectively complements cytological diagnosis. It is based on the preparation of solid-phase material from sediment for morphological evaluation, long-term storage, and additional examinations. Objective: to evaluate the advantages and limitations of cell block technology for routine practice of a cytology laboratory. Materials and methods. We prepared 169 cell blocks from various specimens collected from cancer patients between 2016 and 2017. Each specimen was initially examined using conventional cytology (Cytospin-3). The remaining sediment was mixed with gelatin to prepare cell blocks. After block solidification, we performed its histological examination according to the protocol of biopsy material analysis, followed by staining of sections with hematoxylin and eosin. Results. Thirty-five out of 169 cell blocks (20.7 %) had poor quality. All cell blocks of moderate quality allowed proper examination and correct diagnosis. We have identified the main causes of poor quality of cell blocks and found ways to address typical errors of the preanalytic stage. The article provides several examples illustrating the use of cell block technology in routine morphological diagnostics. Conclusions. The cell block technology effectively complements the cytological method and, therefore, can be recommended for implementation in routine practice of a cytological laboratory.

For many pathologists, the diagnosis of bone diseases remains challenging. Bone pathology requires deep knowledge of special terminology, skills in preparing tissue samples using decalcification, comparison of morphological characteristics and findings of different visualization methods, including X-ray, computed tomography, and magnetic resonance imaging, as well as a multidisciplinary approach with the involvement of an orthopedic surgeon, a specialist in radiation diagnostics, a pathologist, and an oncologist (in case of malignancy).

Radical nephrectomy resection remains the gold standard treatment for localized kidney cancer. One of the main tasks of pathologists is to obtain the amount of predictive information that determines the forecast and tactics of doing business. Therefore, it is very important to introduce standardization of clipping and morphological conclusion. Correct and accurate cutting is the first step to making an accurate diagnosis.

Diffuse midline glioma (DMG), H3 K27M-mutant is a new nosology introduced in the WHO classification of CNS tumors in 2016. It is a rare glial tumor with predominantly astrocytic differentiation, high degree of anaplasia (grade IV), characterized by mutations in the H3F3A or HIST1H3B/C genes with K27M. The typical localization is the midline of the brain, which includes the thalamus, hypothalamus, pineal region, bridge, and spinal cord. The authors present an analysis of 6 cases of DMG with H3 K27M-mutant in patients operated on at the A.L. Polenov Russian Research Institute of Neurosurgery for midline tumors. A combination of diffuse growth type with an exophytic component, with spread to the ventricles or to the chiasmal-sellar region, was noted, had a picture of astrocytic tumors with different degrees of anaplasia: from diffuse astrocytoma to glioblastoma, and in one case with an extensive spread of the tumor by the type of gliomatosis. An accurate diagnosis was established only when immunohistochemical studies were used to detect the expression of mutant H3 K27M.