Background/Objectives: Metastatic colorectal cancer remains a fatal disease, with a 5-year survival rate lower than 15%. The most common metastatic sites are the lungs and the liver, while skin metastases are very rare and often indicate a poor prognosis with a lower survival rate. Methods. Herein, we present the clinical case of a 62-year-old female patient with rectal cancer metastases to the skin of the anogenital and abdominal regions, diagnosed 2 years after completion of treatment of the underlying disease. Results: Histological examination of the skin lesions revealed adenocarcinoma, and expression of the same immunohistochemical markers was also found in the primary tumor and in the cutaneous metastases. However, next-generation sequencing demonstrated differences in the mutational profiles of the primary tumor and metastasis to the skin. Somatic mutations in the APC, TP53, and PTPN11 genes were revealed in primary rectal adenocarcinoma, but another pathogenic TP53 mutation and a frameshift variant in the DYNC1I1 gene were found in cutaneous metastases. The patient underwent several courses of FOLFOX6 chemotherapy in combination with bevacizumab, but the treatment was unsuccessful. An analysis of 50 clinical cases from the literature concerning various manifestations of cutaneous metastases of rectal cancer showed a median survival of 8.5 months from the time of detection of the skin lesions. Conclusions: In this regard, careful skin examination of patients with rectal cancer and timely detection of cutaneous metastases are essential steps in the follow-up of patients who have undergone treatment of the primary tumor.

Background/Objectives: Cowden syndrome (or PTEN hamartoma tumor syndrome) (CS/PHTS) belongs to a group of inherited disorders associated with the development of multiple hamartomas. The clinical presentation of patients may include dysmorphic facial features, macrocephaly, developmental delay, and multiple benign and malignant tumors of various localizations. At the same time, only thyroid cancer is thought to have an increased risk in childhood. Skin lesions in CS/PHTS occur in 90–100% of patients and include multiple tricholemmoma, papilloma, acral keratosis, pigmentation changes, as well as rarer forms like vascular malformations, fibromas, neuromas, melanoma, and basal cell carcinoma. Methods: Next-generation sequencing and Sanger sequencing were used to search for PTEN genetic variants. A histological and immunohistochemical examination of tumor biopsies and skin lesions was performed. Results: A total of 13 patients from six families with CS/PHTS, including 10 children, were described. Seven pediatric patients belonged to families with paternal transmission of the PTEN pathogenic variants, while three others were de novo cases. Atypical manifestations in CS/PHTS were diffuse large B-cell lymphoma in one adult, a renal cell carcinoma, three germ cell tumors, and a linear epidermal nevus in pediatric patients. A literature review of the identified pathogenic variants in the PTEN gene was performed, assessing their clinical significance and analyzing the traditional and modified diagnostic criteria as applied to the pediatric population. Conclusions: Taking into account the low incidence of CS/PHTS, the data presented significantly expand our current understanding of this disease and guide physicians to consider a wider range of possible malignant neoplasms in pediatric patients with CS/PHTS.

Anaplastic thyroid cancer is one of the most prognostically unfavorable tumors. This disadvantage traditionally consisted of a rapid increase in the size of the primary tumor with a tendency to the development of asphyxia and the rapid appearance of distant metastases, as well as a poor response to the recommended treatment methods. The result of many years of efforts by oncologists around the world were several treatment regimens, including an ideal amount of surgical intervention, chemotherapy and radiation therapy, but the effectiveness of this treatment, as well as the patient’s life expectancy after it, could not be called satisfactory. Improving the understanding of the molecular genetic characteristics of tumors, including anaplastic thyroid cancer, provided us with information on two possible features of the genetic apparatus of tumor cells that can have clinical significance: V600E mutations in the BRAF gene and fusion of NTRK genes. The clinical example described in this article is probably the first Russian illustration of the effectiveness of anti-BRAF therapy in a patient with anaplastic thyroid cancer. From our point of view, the benefit of this example is not only to demonstrate the effectiveness of modern targeted therapy, but also the need not to abandon other treatment methods, in this case, radiation therapy to the area of the primary tumor (and by analogy with this, surgical removal of the thyroid tumor glands in case of its resectability).

The main method of treating rare mesenchymal tumors PEComas is surgical removal of the tumor and external-beam radiation therapy has historically been considered ineffective. However, the individual cases in the foreign literature as well as this article authors’ experience in the form of the clinical case provided in it shows the possibility of achieving some anti-tumor effect due to the use of aggressive variants of radiation therapy. The use of variations of stereotactic radiotherapy with high dose per fraction and sum dose as an neoadjuvant and definitive treatment looks promising.

In modern medicine, radiation therapy (RT) is one of the main therapies for cancer. According to the World Health Organization, about 70% of patients diagnosed with cancer require RT at some stage of treatment. Development and improvement of methods for early diagnosis of cancers, multimodal therapy for cancer patients, including surgical intervention, new drug treatment regimens, modern methods of conformal 3D-RT and proton therapy significantly improved the treatment outcomes of patients and increased their life expectancy. Modern RT is a high-tech chain of sequential use of complex technical devices and mathematical calculations to destroy the tumor without adversely affecting the surrounding normal tissues. Some patients develop radiation injuries to normal organs and tissues that reduce their quality of life. Prevention and treatment of such injuries are urgent problems of modern oncology. The article addresses the pathogenesis and mechanism of the development of systemic and local radiation responses, as well as methods of treatment and prevention of some of them. Three electronic databases, including PubMed, Cochrane and EMBASE, and Russian radiotherapists' publications, were used for systematic review in the information retrieval process.

Continuous development of oncology as a science in the last decades and years led to noticeable improvement in treatment outcomes for patients with various malignant tumors. Diagnostics, surgery, radiotherapy significantly contributed to this improvement, however they cannot be compared to the progress achieved through advancements in our knowledge of genetic structure of tumors and subsequent advancements in pharmacology which allowed to achieve qualitatively better survival in oncological patients. These advancements did not leave out such a serious and highly lethal, though fortunately rare, disease as anaplastic thyroid cancer. This article is dedicated to the possibilities of using checkpoint inhibitors in treatment of this pathology to increase expected life span of the patients.