Publications by authors named "Michalova K"

Low-grade endometrial stromal sarcoma (LG-ESS) can present diagnostic challenges, due to its overlapping morphological features with other uterine mesenchymal tumors. Misdiagnosis rates remain significant, and immunohistochemical data for LG-ESS are limited to small series and inconsistent antibody panels. This study aimed to refine the IHC profile of LG-ESS by analyzing a large, molecularly confirmed series of 147 cases using a panel of 24 antibodies, including newer markers like transgelin and smoothelin.

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Juxtaglomerular cell tumor (JxGCT) is a rare type of renal neoplasm demonstrating morphologic overlap with some mesenchymal tumors such as glomus tumor (GT) and solitary fibrous tumor (SFT). Its oncogenic drivers remain elusive, and only a few cases have been analyzed with modern molecular techniques. In prior studies, loss of chromosomes 9 and 11 appeared to be recurrent.

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Molecular classification of endometrial carcinomas (EC) divides these neoplasms into four distinct subgroups based on their molecular background. Given its clinical significance, genetic examination is becoming integral to the diagnostic process. This study aims to share our experience with the molecular classification of EC using immunohistochemistry (IHC) and next-generation sequencing (NGS).

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Article Synopsis
  • - Uterine sarcomas with KAT6B/A::KANSL1 fusion are a new type of tumor that show a mix of traits from low-grade endometrial stromal sarcomas and smooth muscle tumors, which can confuse initial diagnoses.
  • - A study involving 9 such cases found common features like expression of smooth muscle and endometrial stromal markers, as well as the presence of the KAT6B/A::KANSL1 fusion in all tumors.
  • - Despite their bland appearance, these tumors can be aggressive, with some patients experiencing severe outcomes, underscoring the need for accurate recognition and diagnosis for better treatment approaches.
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Objective: Molecular classification of endometrial carcinomas (EC) divides these neoplasms into four distinct subgroups defined by a molecular background. Given its proven clinical significance, genetic examination is becoming an integral component of the diagnostic procedure. Recommended diagnostic algorithms comprise molecular genetic testing of the POLE gene, whereas the remaining parameters are examined solely by immunohistochemistry.

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NTRK-rearranged spindle cell neoplasm represents an emerging entity included in the latest 5th edition of WHO classification of both soft tissue and female genital tumors. By immunohistochemistry, they are commonly positive for CD34, S100 protein, and CD30 and typically harbor fusions of kinase genes such as NTRK1/2/3, RET, and BRAF. In the gynecological tract, they typically affect the uterine cervix or uterine body.

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Uterine tumor resembling ovarian sex cord tumor (UTROSCT) is a rare tumor of uncertain lineage and low malignant potential. Most tumors behave in a benign manner, but a subset of UTROSCT exhibit an aggressive clinical course with recurrences and metastases. The recurrent molecular alterations in UTROSCT mostly represent gene fusions involving NCOA1-3.

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Endometrial carcinomas (EC) of no special molecular profile (NSMP) represent the largest molecular category of EC, comprising a mixture of tumors with different histology and molecular profiles. These facts likely point to different tumor biology, clinical outcomes, and targeted therapy responses within this molecular category. The PIK3CA is currently the only targetable kinase oncoprotein directly implicated in EC carcinogenesis.

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Endometrial stromal tumors are rare lesions with a diverse morphology, which may make achieving the correct diagnosis challenging in some cases. We report a case of a uterine mesenchymal tumor diagnosed as endometrial stromal nodule with a peculiar whorled morphology and GREB1::CTNNB1 fusion confirmed by transcriptome RNA sequencing. The tumor was sharply demarcated, lacked invasive growth, and had benign behavior, as the patient remained without disease recurrence 15 years later.

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Article Synopsis
  • The PLAG1 gene fusions have been found in some uterine myxoid leiomyosarcomas (M-LMS), but there are cases of PLAG1-rearranged uterine sarcomas that do not resemble M-LMS or show smooth muscle markers.
  • A study involving 11 cases of these sarcomas showed diverse features, with patient ages ranging from 34 to 72 years and tumor sizes between 6.5 to 32 cm.
  • Follow-up data indicated varying outcomes; while some patients showed no disease evidence, others experienced disease progression or died within a few years, and the tumors displayed significant morphological diversity, including unusual characteristics like hyalinized stroma and adipocytic differentiation
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A syndromic association between a subset of testicular/paratesticular neoplasms is well established. Such examples include Carney complex and large cell calcifying Sertoli cell tumor, Peutz-Jeghers syndrome and intratubular large cell hyalinizing Sertoli cell neoplasia, and VHL syndrome and clear cell papillary cystadenoma of the epididymis.However, recent studies proposed potential novel links between some testicular and paratesticular neoplasms with certain tumor syndromes.

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a-Methylacyl coenzyme A racemase (AMACR) is traditionally considered to be a marker of papillary renal cell carcinoma. However, AMACR expression can be seen in other renal tumors. The aim of this study was to investigate AMACR immunoreactivity within the spectrum of clear cell renal cell neoplasms.

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Alterations in kinase genes such as NTRK1/2/3, RET, and BRAF underlie infantile fibrosarcoma (IFS), the emerging entity 'NTRK-rearranged spindle cell neoplasms' included in the latest WHO classification, and a growing set of tumors with overlapping clinical and pathological features. In this study, we conducted a comprehensive clinicopathological and molecular analysis of 22 cases of IFS and other kinase gene-altered spindle cell neoplasms affecting both pediatric and adult patients. Follow-up periods for 16 patients ranged in length from 10 to 130 months (mean 38 months).

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  • Two benign adenomatous lesions in the sinonasal tract are recognized, REAH and SH, but researchers identified 10 new related lesions averaging 3.6 cm in size.
  • These new tumors feature a distinctive component called atypical sinonasal glands arising in SH (ASGSH), characterized by atypical cell structures, secretory layers, and unique shapes with secretions reminiscent of thyroid follicles.
  • Genetic analysis revealed mutations in the BRAF, RET, and FAT1 genes among these lesions, suggesting a neoplastic nature and supporting their classification as new entities in the sinonasal tract.
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  • Spermatocytic tumors (ST) are rare, mostly benign germ cell tumors found in older men, but some can behave aggressively, especially when they transform into a sarcomatoid form.
  • In a study of 27 samples from 25 patients, researchers identified two genomic subgroups of STs: one with stable genomes and specific RAS/RAF mutations, and another with altered ploidy but no recurrent mutations.
  • Aggressive cases of ST were linked to mutations in the TP53 gene and an increase in chromosome 12p, indicating distinct biologic progression patterns within the tumor types.
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EWSR1::POU2AF3 (COLCA2) sarcomas are a recently identified group of undifferentiated round/spindle cell neoplasms with a predilection for the head and neck region. Herein, we report our experience with 8 cases, occurring in 5 men and 3 women (age range, 37-74 years; median, 60 years). Tumors involved the head/neck (4 cases), and one each the thigh, thoracic wall, fibula, and lung.

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Upper tract urothelial carcinoma (UTUC) is the third most common malignancy associated with Lynch syndrome (LS). The current European urology guidelines recommend screening for LS in patients with UTUC up to the age of 60 years. In this study, we examined a cohort of patients with UTUC for potential association with LS in order to establish the sensitivity of current guidelines in detecting LS.

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Large cell calcifying Sertoli cell tumour (LCCSCT) is a type of testicular sex cord-stromal tumour that may occur sporadically or in the context of Carney complex and other genetic syndromes. A subset is clinically malignant, and the molecular mechanisms that drive such aggressive behaviour remain unknown. METHODS AND RESULTS: We analysed 21 samples from 20 patients with LCCSCT (12 non-metastasising and eight metastasising) using PRKAR1A immunohistochemistry (IHC) and next-generation sequencing.

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Compared to the WHO classification of the male genital tumors in 2016, minimal changes were introduced in the current WHO 2022. Classification of germ cell tumors remains the same as in the previous edition, dividing germ cell tumors into those derived from germ cell neoplasia in situ (GCNIS) and those independent of GCNIS. The group of GCNIS derived germ cell tumors is essentially unchanged.

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Similarly to testicular tumors, key changes on penile and scrotal neoplasia were incorporated into WHO classification 2016. Therein, penile squamous cell carcinomas were divided into two groups based on the pathogenesis, namely HPV-associated and HPV-independent. This remains unchanged in WHO classification 2022.

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The 5th edition of WHO classification of adult renal tumors introduced a couple of changes in existing, well established entities, as well as some new distinct renal tumors. Papillary renal cell carcinoma (RCC) is no longer divided into type 1 and type 2. Type 1 is now called “classic” variant and type 2 doesn´t exist anymore.

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Myoid gonadal stromal tumours (MGST) represent a rare type of testicular sex cord-stromal tumour that has recently been recognised as a distinct entity by the World Health Organization (WHO) classification of genitourinary tumours. MGSTs affect adult men and have been reported to behave in an indolent fashion. Histologically, MGSTs are pure spindle cell neoplasms that coexpress SMA and S100 protein.

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Epithelioid fibrous histiocytoma (EFH) is a distinctive cutaneous neoplasm with a relatively variable morphological appearance. Recently, it has been shown that this tumor is molecularly characterized by ALK gene fusions. We report three EFHs with unusual histological presentation represented by a prominent/predominant spindle cell proliferation arranged in a variably storiform/whirling architectural pattern with or without stromal sclerosis.

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Article Synopsis
  • Predicting the clinical behavior of chromophobe renal cell carcinoma (ChRCC) has been difficult due to its diverse morphologic and genetic profiles.
  • This study analyzed 89 rare subtypes of ChRCC compared to 70 classic/eosinophilic cases to see how histologic diversity affects survival outcomes.
  • No significant differences in clinical outcomes were found between the rare subtypes and classic/eosinophilic groups, reinforcing that factors like sarcomatoid differentiation and tumor necrosis are linked to poorer outcomes across all subtypes.
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