Pediatric adrenocortical neoplasms (ACNs) are extremely rare tumors in contrast to their adult counterparts. Distinguishing benign from malignant is challenging based on pure morphologic grounds. Previously, 2 scoring systems were proposed in pediatric ACN, including the Wieneke criteria (WC) and its modified version (modified WC [mWC]). In adults, the reticulin algorithm (RA) has proven inexpensive, reliable, predictive, and reproducible; however, it has been validated only recently in children in a limited number of cases. This study aims to assess the RA utility compared with other scoring systems in a series of 92 pediatric ACNs. All cases were individually scored, and mitotic rate cutoffs were recorded. Reticulin alterations were classified as quantitative and qualitative. Outcome data were available in 59/92. The median age was 5 years (0.1 to 18 y) with an M:F of 0.6. Clinical presentation included virilization (39%), Cushing syndrome (21%), other symptoms (4%), and asymptomatic (36%). The reticulin framework was intact in 27% and altered in 73% of cases, showing qualitative (22%), quantitative (73%), and both (5%) alterations. In patients with favorable outcomes, 59% showed either intact reticulin or qualitative alteration compared with the unfavorable outcome group, where 90% showed quantitative alterations. All scoring systems WC (P < 0.0001), mWC (P = 0.0003), and the adult/pediatric RA (P < 0.0001) had predictive value. The RA is comparable to WC and mWC, easier to apply, and is the most sensitive histopathological approach to identifying aggressive behavior in pediatric ACN. Its integration into the WC might be helpful in ACN of uncertain malignant potential and deserves further investigation.

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.

Somatic internal tandem duplication of 3’ of BCOR (BCOR ITD) has been found in clear cell sarcomas of the kidney (CCSK), soft tissue undifferentiated round cell sarcomas/primitive myxoid mesenchymal tumors of infancy (URCS/PMMTI), and a subgroup of central nervous system high-grade neuroepithelial tumors (CNS-HGNET). BCOR ITD+ tumors share morphologic features. Expression of OLIG2 and epidermal growth factor receptor (EGFR) has been reported in CNS-HGNET with BCOR ITD. Here, we characterize OLIG2 and EGFR expression in URCS/PMMTI with BCOR ITD. Paraffin blocks of 9 polymerase chain reaction-confirmed soft tissue BCOR ITD+ tumors (URCS/PMMTI) were immunophenotyped for OLIG2 and EGFR expression and scored semiquantitatively by percentage of positive cells and intensity of staining as negative, 1+, 2+, and 3+. Fluorescence in situ hybridization (FISH) for EGFR amplification was performed (amplification EGFR/CEP7 ratio ≥2.0). All 9 tumors showed membrane/cytoplasmic expression of EGFR, strong and diffuse (3+) in 8 cases; weak (+2) in 1. FISH detected no EGFR amplification. OLIG2 was negative in all. EGFR is overexpressed in pediatric URCS/PMMTI with BCOR ITD and may be related to transcriptional upregulation of EGFR by BCOR ITD. OLIG2 negative staining differentiates URCS/PMMTI from CNS-HGNET. This finding may further support the possibility that these tumors have a different stem cell of origin.

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.

Blue rubber bleb nevus syndrome (BRBNS) also called Bean's syndrome is a rare disorder characterized by mucocutaneous angiomatose multiple cutaneous venous malformations. Pathogenesis of the BRBNS is caused by the somatic mutations in angiopoietin receptor gene TEK. These mutations cause ligand-independent activation of the tyrosine kinase receptor and the PI3K / AKT pathway and involve the mTOR in the pathological process in a specific way. There are no universally effective methods for treating systemic forms of vascular malformations currently. However, recent numerous reports have shown the advantages of rapamycin, an mTOR inhibitor, as a well-tolerated and effective therapy in patients with vascular abnormalities, in particular with diffuse angiomatose. This article presents a clinical case of a 5-years old patient with a diagnosis of iron deficiency anemia, who has been treated for a long time and received iron supplements therapy without achieving any effect. The diagnosis of Bean's syndrome was established after 5 years from the first clinical manifestation and based on clinical, laboratory and instrumental methods. The cause of iron deficiency anemia was established. It was repeated chronic bleedings from multiple sites of the gastrointestinal mucosa vessels. Prescribed rapamycin therapy allowed to contain gastrointestinal bleeding, to reduce the size of vascular lesions and to prevent the formation of new ones. Parents gave their consent to use information about the child in the article.

Mosaic RASopathies are rare conditions caused by postzygotic mutations in RAS/MAPK signaling pathway genes arising during embryonic development. They are mainly characterized by a combination of epidermal nevi with extra-cutaneous manifestations. Choosing between different entities can be challenging because of their substantial clinical and genetic overlap. Our aim was to demonstrate the importance of genetic background in accurate diagnosis and further prognostic assessment of disease progression by analyzing genotype–phenotype correlations within this clinical group. The study enrolled 18 patients (10 males, 8 females) aged from 1 month to 21 years with congenital nevi of craniofacial localization and variable extracutaneous abnormalities. DNA isolated from peripheral blood lymphocytes and affected tissues (nevus, tumor) was analyzed using a targeted next-generation sequencing (NGS) panel covering RAS/MAPK pathway genes, followed by Sanger sequencing. Eight patients were diagnosed with Schimmelpenning–Feuerstein–Mims syndrome caused by postzygotic mutations in the HRAS (n=4) or KRAS (n=4) genes. Seven patients were clinically diagnosed with phacomatosis pigmentokeratotica, and mosaic mutations were identified in the HRAS (n=4), KRAS (n=2), or BRAF (n=1) genes. Two patients with similar phenotypes carried somatic mutations in the PIK3CA and FGFR2 genes, respectively, and in one case no mutation was detected in the affected skin. We compared the spectrum of extracutaneous anomalies depending on the mutation in a specific gene by combining our data with data from other clinical cases of mosaic RASopathies described in the literature. In summary, 53 cases with HRAS postzygotic mutations and 41 cases with KRAS mutations were involved in the analysis of genotype–phenotype correlations. Hypophosphatemic rickets and malignant tumors were associated with mutations in the HRAS gene, while ophthalmological, neurological, cardiovascular, and renal disorders were more common in KRAS-mutant patients. Thus, genetic testing of affected tissue is essential for accurate diagnosis of these mosaic disorders. Taking into account clinical manifestations and the identified genotype–phenotype correlations may further assist in prognosis and patient management.