Vol 9, No 1 (2026)

Lobular breast cancer is a unique type with pathogenesis intrinsically linked to inactivation of the tumor suppressor gene CDH1 which encodes the E-cadherin protein. The loss of E-cadherin disrupts intercellular adhesion and polarity, leading to dissociation of tumor cells and their characteristic “single-file” invasive growth pattern. CDH1 inactivation most commonly occurs as a result of truncating or missense mutations, as well as loss of heterozygosity, and is a hallmark of both hereditary and sporadic forms of lobular breast cancer. CDH1 status has important prognostic significance, as it correlates with an earlier age of onset, an increased risk of metastasis to atypical sites (e.g., gastrointestinal tract, peritoneum, ovaries), and potential resistance to hormonal therapy. Studying the role of the CDH1 gene offers prospects for the development of targeted therapy and optimization of patient treatment approaches. Nevertheless, additional research is required to fill the existing gaps.

Suspicion of bone tumor requires radiological diagnostics, while the main method of diagnosis is histological examination. The article presents diagnostic radiological and morphological signs of benign bone-forming tumors. Morphological diagnosis of these tumors has several specific features. Information on etiology and clinical picture of these lesions is presented.

The article presents a review of development of approaches to morphological assessment of therapeutic effect in breast cancer after neoadjuvant therapy. Early evaluation systems based primarily on qualitative and semi-quantitative characteristics of tumor regression (B. Chevallier et al., D. M. Sataloff et al., Miller–Payne system) are discussed. Special attention is paid to modern techniques of assessment of therapeutic response, primarily the residual cancer burden. The article reflects the evolution of approaches from descriptive scales to standardized quantitative models which allow for more objective evaluation of residual tumor and disease prognosis.

Adamantinoma comprises about 0.3 % of all primary malignant tumors of the bones. Currently it is considered a biphasic tumor characterized by variety of morphological types. Usually, the tumor is located in the long bones (97 %), in the majority of cases (80–85 %) in the tibia. It has indolent character and long progressive clinical course which lead to late diagnosis.

A clinical case of adamantinoma of the tibia in a young female patient with long-term follow-up, development of local recurrences and metastases is presented.

The diagnosis of cutaneous melanoma and its regional manifestations is among the areas of clinical oncology and dermatopathology most susceptible to terminological inconsistencies. This is largely due to the fact that several key terms simultaneously perform multiple functions: they define topographic and staging criteria, are incorporated into clinical guidelines, and serve as elements of communication between clinicians and pathologists. In this context, seemingly “accurate” calques from English may shift the meaning of the original term and create ambiguity in its practical interpretation.

Against this background, a specific type of professional error can be identified: one that arises not from misinterpretation of morphological features, but from the incorrect use of fundamental definitions. When such errors appear in regulatory documents and educational materials, they may become entrenched in professional practice and be reproduced across documents of different levels, thereby hindering the standardization of protocols and the comparability of data with international nomenclature. One illustrative example is the use of the phrase “transitory metastases” in Russian as a translation of the term “in-transit metastases”.

This article analyzes the semantic inadequacy of this calque, explains the mechanism underlying its emergence, and substantiates appropriate Russian equivalents that can be applied in clinical guidelines and standardized pathology reporting.