[Microglandular adenosis of the breast]

The presented case describes the difficulties of diagnosis of the breast microglandular adenosis (MGA), taken by clinicians for a malignant process due to the nature of growth and large size. Criteria for histological and immunohistochemical diagnosis and differentiation of MGA with malignant neoplasms, in particular, with tubular breast carcinoma, are presented. Taking into account the rarity of the pathology and the absence of described cases in the Russian-language literature, the observation is of interest to pathologists and clinicians.

[Thyroid-like follicular carcinoma of the kidney]

Thyroid-like follicular carcinoma of the kidney (TLFCK) is an extremely rare histological variant of renal cell carcinoma, not yet included in the WHO list of tumors. This tumor has a characteristic morphological structure strikingly resembling follicular carcinoma of the thyroid gland, but differing from itby the immunophenotype of tumor cells. TLFCK is characterized by an indolent clinical course, rarely metastases, and even the presence of metastases does not lead to a worsening of the prognosis for the patient. Described a case of TLFCK diagnosed in a 38-year-old patient, observed clinically for 8 years, without metastases during this time, and removed by focal kidney resection. The paper presents the macroscopic and microscopic characteristics of the tumor, immunohistochemical profile, and discusses the issues of differential diagnosis.

[Metastatic lesion of the bone marrow caused by primary angiosarcoma of the spleen]

The article presents a rare case of bone marrow metastasis of the spleen angiosarcoma. The observation is of particular interest due to the fact that secondary bone marrow damage in angiosarcoma in the vast majority of cases is due by primary tumor growth in the spleen. Clinically, such cases may resemble the course of blood diseases with hematological disorders and splenomegaly. Patients come into the field of view of a hematologist, and the final diagnosis is unexpected to the attending physician. Detection of angiosarcoma growth in a bone marrow trephine biopsy during morphological examination can be a rare finding for a pathologist. In this regard, the presented case is of interest not only for pathologists, but also for doctors of clinical specialties.

[Rare kidney tumor - thyroid-like follicular carcinoma]

The literature review provides an analysis of a rare malignant tumor of the kidney: thyroid-like follicular carcinoma of the kidney (TLFCK). In morphology, this tumor is extremely similar to thyroid follicular carcinoma, but the immunophenotype of tumor cells is different. TLFCK has an indolent clinical course, rarely metastasizes, and even the development of metastases does not mean an unfavorable prognosis for the patient. The literature review presents the features of the clinical course of the disease, macroscopic, microscopic, immunohistochemical characteristics of the tumor and typical cytogenetic breakdowns. Particular attention is paid to the issues of differential diagnosis of the tumor with other pathological processes that may microscopically resemble TLFCK.

11C-radiolabeled aptamer for imaging of tumors and metastases using positron emission tomography- computed tomography

Identification of primary tumors and metastasis sites is an essential step in cancer diagnostics and the following treatment. Positron emission tomography-computed tomography (PET/CT) is one of the most reliable methods for scanning the whole organism for malignancies. In this work, we synthesized an 11C-labeled oligonucleotide primer and hybridized it to an anti-cancer DNA aptamer. The 11C-aptamer was applied for in vivo imaging of Ehrlich ascites carcinoma and its metastases in mice using PET/CT. The imaging experiments with the 11C-aptamer determined very small primary and secondary tumors of 3 mm2 and less. We also compared 11C imaging with the standard radiotracer, 2-deoxy-2-[fluorine-18]fluoro-D-glucose (18F-FDG), and found better selectivity of the 11C-aptamer to metastatic lesions in the metabolically active organs than 18F-FDG. 11C radionuclide with an ultra-short (20.38 min) half-life is considered safest for PET/CT imaging and does not cause false-positive results in heart imaging. Its combination with aptamers gives us high-specificity and high-contrast imaging of cancer cells and can be applied for PET/CT-guided drug delivery in cancer therapies.

[Whipple's disease: A case of postmortem diagnosis]

The paper describes a case of the postmortem diagnosis of Whipple's disease, a rare bacterial infection, in a patient with multiple organ dysfunction showing intestinal manifestations with massive retroperitoneal lymphadenopathy. Histochemical and electron microscopic methods were used to examine the patient, which showed the morphological changes occurring in the lymph nodes and bowel and the ultrastructural characteristics of Tropheryma whipplei while examining the sections primarily fixed in formalin and embedded in paraffin. The systemic pattern of the disease is depicted.