Molecular substratification of endometrial carcinomas with no special molecular profile (NSMP) by using a limited NGS custom panel may facilitate effective patient selection for the PIK3CA-targeted therapy.

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. Investigating a unique single-institution cohort, we attempted to stratify NSMP ECs based on the presence of the PIK3CA pathogenic mutation. Those cases were further analyzed for other well-established-associated oncogenic driver gene mutations. Histological and clinical variables were also correlated in each case. Altogether, 175 ECs were prospectively tested by a limited custom NGS panel containing ARID1A, BCOR, BRCA1, BRCA2, CTNNB1, KRAS, MLH1, MSH2, MSH6, NRAS, PIK3CA, PMS2, POLD1, POLE, PTEN,and TP53 genes. We identified 24 PIK3CA mutated cases in the group of 80 NSMP ECs, with another co-occurring mutation in at least one oncogenic driver gene (CTNNB1, PTEN, ARID1A, KRAS, BCOR, PMS2) in 19 cases. In conclusion, a limited NGS panel can effectively test EC tissue for specific pathogenetically relevant oncogene mutations. The NSMP EC category contains 30% of the PIK3CA mutated cases. Of those, 21% contain the PIK3CA mutation as a sole EC-associated oncogene mutation, while 79% harbor at least one more mutated gene. These findings may inform future healthcare planning and improve the effectiveness of EC patient selection for the PIK3CA-targeted therapy.

PLAG1-Rearranged Uterine Sarcomas: A Study of 11 Cases Showing a Wide Phenotypical Spectrum Not Limited to Myxoid Leiomyosarcoma-Like Morphology.

PLAG1 gene fusions were recently identified in a subset of uterine myxoid leiomyosarcomas (M-LMS). However, we have encountered cases of PLAG1-rearranged uterine sarcomas lacking M-LMS-like morphology and/or any expression of smooth muscle markers. To better characterize their clinicopathologic features, we performed a multiinstitutional search that yielded 11 cases. The patients ranged in age from 34 to 72 years (mean, 57 years). All tumors arose in the uterine corpus, ranging in size from 6.5 to 32 cm (mean, 15 cm). The most common stage at presentation was pT1b (n = 6), and 3 cases had stage pT1 (unspecified), and 1 case each presented in stages pT2a and pT3b. Most were treated only with hysterectomy and adnexectomy. The follow-up (range, 7-71 months; median, 39 months) was available for 7 patients. Three cases (7-21 months of follow-up) had no evidence of disease. Three of the 4 remaining patients died of disease within 55 to 71 months, while peritoneal spread developed in the last patient, and the patient was transferred for palliative care at 39 months. Morphologically, the tumors showed a high intertumoral and intratumoral heterogeneity. M-LMS-like and epithelioid leiomyosarcoma-like morphology were present in 3 and 5 primary tumors, respectively, the remaining mostly presented as nondescript ovoid or spindle cell sarcomas. Unusual morphologic findings included prominently hyalinized stroma (n = 3), adipocytic differentiation with areas mimicking myxoid liposarcoma (n = 2), osteosarcomatous differentiation (n = 1), and undifferentiated pleomorphic sarcoma-like areas (n = 1). The mitotic activity ranged from 3 to 24 mitoses per 10 high-power fields (mean, 9); 3 of 10 cases showed necrosis. In 3 of 11 cases, no expression of smooth muscle actin, h-caldesmon, or desmin was noted, whereas 5 of 5 cases expressed PLAG1. By RNA sequencing, the following fusion partners were identified: PUM1, CHCHD7 (each n = 2), C15orf29, CD44, MYOCD, FRMD6, PTK2, and TRPS1 (each n = 1). One case only showed PLAG1 gene break by fluorescence in situ hybridization. Our study documents a much broader morphologic spectrum of PLAG1-rearranged uterine sarcomas than previously reported, encompassing but not limited to M-LMS-like morphology with occasional heterologous (particularly adipocytic) differentiation. As it is currently difficult to precisely define their line of differentiation, for the time being, we suggest using a descriptive name "PLAG1-rearranged uterine sarcoma."

Methylation analysis as an auxiliary tool in cytological diagnostics of infrequent anogenital lesions - a pilot study.

Methylation silencing of certain cellular genes is a sign of carcinogenesis progression and therefore tests that detect methylation could be used in the diagnosis or staging of malignant diseases. In the diagnosis of squamous cell carcinomas of the cervix which are almost 100% caused by long-term infection with highrisk human papillomavirus (HR-HPV), methylation silencing of certain cellular genes is a highly specific marker of advanced dysplastic lesions and appears to result from aberrant activation of the methyltransferase DNMT1 by viral oncoproteins E6 and E7. A methylation test performed on a cervicovaginal cytology specimen allows to increase the diagnostic value of this non-invasive test and to select patients with severe squamous cell lesions for follow-up. Other less frequent anogenital malignancies that are induced by HR-HPV to a lesser extent can also be detected by cytological examination - glandular lesions of various origins, most commonly cervical and endometrial adenocarcinomas and anal carcinoma. The aim of our pilot study was to evaluate the utility of a methylation test for the diagnosis of these malignancies in a cohort of 50 liquid-based cervicovaginal cytologies with glandular lesion and 74 liquid-based anal cytologies from HIV-positive men having sex with men who are at high risk for anal cancer development.

Upgrade Rate and Predictive Factors Associated With Breast Papillary Lesions on Core Biopsy: A Canadian Experience.

Background: Papillary lesions of the breast are a heterogeneous group, encompassing a wide range of lesions. The histologic distinction between papillary breast lesions remains challenging, especially on core biopsy specimens. Aim: This study aimed to determine the rate of upgrade to atypia or malignancy of biopsy-proven papillary lesions on surgical follow-up and to assess for factors associated with an upgrade in Greater Vancouver, BC, Canada. Materials and Methods: This is a retrospective population-based study of all breast papillary lesions diagnosed on core biopsy between 2017 and 2019 in the Fraser Health Authority in Greater Vancouver, Canada. Patients were retrieved from the laboratory information system. Patient demographics, histopathologic, and radiologic findings were analyzed. Results: A total of 269 specimens from 269 patients (mean 61.1 years), including 265 female and 4 male patients, were included in the study. Of the 269 specimens, 129 (48%) were intraductal papillomas and 140 (52%) were atypical papillary lesions. The overall upgrade rate among papillomas was 11.6% (15 of 129) on final excision. The mean age of patients diagnosed with papilloma on core biopsy was significantly younger than those with atypical papillary lesions (55.6 vs 66.1 years, P < .0001). Lesion size in patients with papillomas on core biopsy was significantly smaller than those with atypical papillary lesions (11.1 vs 15.1 mm, P = .001). The upgrade rates in patients <55 and ≥55 years were 4.9% and 13.2%. Size (P = .004) and atypia on core biopsy (P = .009) were significantly associated with upgrade. Older age (>55 years) (OR = 5.3, 95% CI: 1.04-27.08) was an independent predictor of upgrade among papillomas. Size, location, and Breast Imaging-Reporting and Data System (BI-RADS) radiologic categories in our study were not associated with predicting the upgrade of papillomas. Conclusion: Our data suggest that the risk of upgrade to atypia or malignancy is sufficient to warrant the excision of benign papillomas of any size in patients aged ≥55 years. In patients younger than 55 years, observation with close clinical and radiological follow-up without surgery may be sufficient. Our findings also support surgical excision of papillomas diagnosed on core biopsy when associated with atypia.

The changes and updates in the fifth edition of the WHO Classification of prostate tumors.

The fifth edition of the WHO classification of prostate tumors provides new insight into prostate cancer pathogenesis supported by molecular data. It discards the terms low-grade PIN and high-grade PIN. The new entity „Treatment-related neuroendocrine prostatic carcinoma“ is introduced. The importance of the diagnosis of intraductal carcinoma is highlighted. The terminology of prostatic basocellular carcinoma is upgraded. Some cancer subtypes are being relocated to different chapters based on new findings. Also, the role of the prostate as an origin of hereditary cancer is stressed. Finally, the new therapeutic approaches are mentioned.

Primary cardiac synovial sarcoma mimicking SARS-CoV-2 associated pericarditis.

Primary cardiac synovial sarcoma is an extremely rare tumor with a higher incidence in young men. The mean age of occurrence is 32 years. Synovial sarcomas are tumors with high aggressiveness, proliferate rapidly and metastasize to regional and distant lymph nodes or surrounding organs. The typical location of synovial sarcoma of the heart is the atrial and ventricular septum. Its size, the degree of infiltration of the surrounding tissues and the presence of metastases influence clinical symptoms, which are very non-specific. The low specificity of the symptoms complicates the clinical diagnosis and in most cases the tumor is detected during its progression or incidentally. The final diagnosis is based on histological examination. The primary and only method of treatment is a surgical solution with an effort to completely resect the tumor, followed by aggressive palliative chemotherapy. In the following paper, we present a case report of a 32-year-old man who was diagnosed with synovial cardiac sarcoma only on the basis of exacerbation of non-specific subjective complaints due to the complication in the form of of aneurysmal bleeding of the tumor mass.

Prevalence of oral and anal human papillomavirus infection in Czech predominantly HIV-positive men having sex with men - data from a previously unreported population.

BACKGROUND: HIV-positive men who have sex with men (MSM) are more likely to experience human papillomavirus (HPV) infection. The persistent HPV infection is the major factor in the development of anal and oropharyngeal neoplasms. Data on the prevalence of anal and oral HPV in MSM are almost absent from the countries of Central and Eastern Europe. We conducted a cross-sectional study focused on the prevalence of oral and anal HPV infections and the relationship between current anal and oral HPV intrapersonal infection in a Czech population of predominantly HIV-positive MSM. METHODS: Oral gargle and anal swab samples from 205 predominantly HIV-positive MSM from the Czech Republic were analysed for HPV infection using PCR. Selected sociodemographic and clinical data were correlated with HPV detection using generalized linear models and multivariate analysis. RESULTS: HPV infection was detected in 183 (96.8%) anal and 48 (23.6%) oral samples. The most common type of HR-HPV was HPV16 in both anal (25.4%) and oral (2.5%) samples. Multiple anal HPV infections and the presence of vaccine-targeted HR-HPV types were significantly correlated with abnormal anal cytology and HIV status. CONCLUSION: The prevalence of anal HPV infection in Czech predominantly HIV-positive MSM ranks among the highest reported, while oral HPV prevalence is consistent with MSM populations. Minimal overlap of oral and anal HPV types within a patient was observed.

The significance of the fusion partner gene genomic neighborhood analysis in translocation-defined tumors.

INTRODUCTION: This study presents a novel molecular parameter potentially co-defining tumor biology-the total tumor suppressor gene (TSG) count at chromosomal loci harboring genes rearranged in fusion-defined tumors. It belongs to the family of molecular parameters created using a black-box approach. METHOD: It is based on a public curated Texas TSG database. Its data are regrouped based on individual genes loci using another public database (Genecards). The total TSG count for NTRK (NTRK1; OMIM: 191315; NTRK2; OMIM: 600456; NTRK3; OMIM: 191316), NRG1 (OMIM: 142445), and RET (OMIM: 164761) rearranged tumors in patients treated with a theranostic approach is calculated using the results of recently published studies. RESULTS: Altogether 138 loci containing at least three TSGs are identified. These include 21 "extremely hot" spots, with 10 to 28 TSGs mapping to a given locus. However, the study falls short of finding a correlation between tumor regression or patient survival and the TSG count owing to a low number of cases meeting the study criteria. CONCLUSION: The total TSG count alone cannot predict the biology of translocation-defined tumors. The addition of other parameters, including microsatellite instability (MSI), tumor mutation burden (TMB), homologous recombination repair deficiency (HRD), and copy number heterogeneity (CNH), might be helpful. Thus a multi-modal data integration is advocated. We believe that large scale studies should evaluate the significance and value of the total TSG count.

Oral presentation of paraneoplastic pemphigus as the first sign of tonsillar HPV associated squamous cell carcinoma. A case report.

BACKGROUND: Paraneoplastic pemphigus (PNP) in the oral cavity is a rare variant of blistering pemphigus disease closely associated with mostly malignant tumors. The diagnosis may even precede an underlying malignancy enabling early detection. Here, we describe a previously unreported case of PNP associated with HPV-related tonsillar squamous cell carcinoma. METHODS AND RESULTS: A 50-year-old woman was referred to a dentist because of painful oral lesions resembling aphthae major and minor. Later, blisters appeared and an incisional biopsy was performed. Histological examination revealed an unusual coexistence of subepithelial and intraepithelial blisters raising suspicion of paraneoplastic pemphigus. The patient underwent 18F-FDG PET/MRI, showing a metabolically active process in the left palatal tonsil. Diagnostic biopsy revealed HPV type 16 associated tonsillar squamous cell carcinoma. A left tonsillectomy with elective left-sided neck dissection was performed. The postoperative period was complicated by bilateral fluidothorax. Two weeks after radical tumor removal, the mucosal and skin lesions of PNP disappeared. The patient currently shows no evidence of recurrence either of malignancy or PNP eight months after the surgery. CONCLUSION: PNP is a rare autoimmune blistering disease characterized by polymorphous cutaneous and mucosal lesions associated with internal neoplasms including HPV associated squamous cell carcinoma of a tonsil. In order to identify an occult malignancy, a whole-body PET/CT or PET/MRI scan is recommended. Rarely, accurate patient management may depend on the dentist being familiar with this entity and on interdisciplinary cooperation involving dermatologist, radiologist, pathologist, and pneumologist. A strict patient follow-up is indicated.

Prevalence of high-risk human papillomavirus DNA and mRNA and its association with abnormal anal cytology in the Czech male anal cancer screening cohort.

BACKGROUND: Anal cancer (AC) screening is justified in high-risk populations, particularly HIV-positive men having sex with men (MSM). HR-HPV testing could improve the efficiency of cytologically based screening of AC, as in the screening of biologically analogical cervical cancer. The specificity of HR-HPV testing is influenced by the prevalence of HR-HPV infection in the screened population. Reported anal HR-HPV DNA prevalence in MSM is high, but HR-HPV mRNA reflects rather long-term infections and is more specific for high-grade lesions. However, no data were published about HR-HPV DNA and mRNA prevalence in the Czech AC screening population. METHOD: Results of liquid-based anal cytology of 203 predominantly HIV-positive MSM from the Czech AC screening cohort were correlated with results of DNA and E6/E7 mRNA testing of 14 HR-HPV types, and HPV16 genotyping. Eighty-one MSM underwent a standard anoscopy. RESULTS: A total of 109 (53.7%) samples had abnormal cytology, with 12 (5.9%) ASC-H/HSIL, 67 (33.0%) samples cytologically negative, and 27 (13.3%) unsatisfactory. HR-HPV DNA was detected in 134 (66.0%) and HR-HPV RNA in 72 (35.5%) anal smears. HR-HPV mRNA and HPV16 mRNA positivity were associated with abnormal cytology (p = .0037, p = .0021). No significant association was found between HR-HPV DNA or HPV16 DNA positivity and abnormal cytology. No high-grade lesions were revealed by anoscopy. CONCLUSION: Prevalence of anal HR-HPV DNA among Czech MSM is high, however, the prevalence of HR-HPV mRNA is half and associated with abnormal cytology. Our results indicate an increased efficiency of cytological screening when combined with HR-HPV mRNA testing.

SARS-CoV-2 RNA may rarely be present in a uterine cervix LBC sample at the asymptomatic early stage of COVID 19 disease.

OBJECTIVE: Currently, it is thought that uterine cervix mucosal samples present a low risk of SARS-CoV-2 exposure. So far, there is no evidence of SARS-CoV-2 detection in Papanicolaou (Pap) smears. Nevertheless, clinicians could be exposed unaware to the coronavirus while performing and handling a Pap smear. We aimed to retrospectively evaluate the presence of SARS-CoV-2 RNA in cervical liquid-based cytology (LBC) samples in women who tested positive for a nasopharyngeal COVID-19 PCR test. METHODS: From our laboratory database, we identified patients with data on a cervical cancer screening LBC sample paired with a positive nasopharyngeal COVID-19 PCR test. Relevant LBC samples taken within an incubation period of 14 days and post-onset RNA shedding interval of 25 days were subsequently tested for SARS-CoV-2 RNA using RT-PCR tests. RESULTS: The study group consisted of 102 women. Of those, 23 LBC samples were tested. SARS-CoV-2 RNA was detected in one LBC sample from a 26-year-old asymptomatic woman taken six days before reporting headaches and knee arthralgia with a positive nasopharyngeal SARS-CoV-2 RT-PCR test. CONCLUSIONS: It is possible to detect SARS-CoV-2 RNA in cervical LBC samples at an early asymptomatic stage of COVID-19. In general, this finding is infrequent in asymptomatic women who tested SARS-CoV-2 positive within an incubation of 14 days and a post-onset RNA shedding period of 25 days. We fully support the current thinking that cervical LBC samples from asymptomatic women pose a low risk of SARS-CoV-2 exposure and can be handled in the frame of good microbiological practice and procedures.

Identification of tumors with NRG1 rearrangement, including a novel putative pathogenic UNC5D-NRG1 gene fusion in prostate cancer by data-drilling a de-identified tumor database.

The fusion genes containing neuregulin-1 (NRG1) are newly described potentially actionable oncogenic drivers. Initial clinical trials have shown a positive response to targeted treatment in some cases of NRG1 rearranged lung adenocarcinoma, cholangiocarcinoma, and pancreatic carcinoma. The cost-effective large scale identification of NRG1 rearranged tumors is an open question. We have tested a data-drilling approach by performing a retrospective assessment of a de-identified molecular profiling database of 3263 tumors submitted for fusion testing. Gene fusion detection was performed by RNA-based targeted next-generation sequencing using the Archer Fusion Plex kits for Illumina (ArcherDX Inc., Boulder, CO). Novel fusion transcripts were confirmed by a custom-designed RT-PCR. Also, the aberrant expression of CK20 was studied immunohistochemically. The frequency of NRG1 rearranged tumors was 0.2% (7/3263). The most common histologic type was lung adenocarcinoma (n = 5). Also, renal carcinoma (n = 1) and prostatic adenocarcinoma (n = 1) were found. Identified fusion partners were of a wide range (CD74, SDC4, TNC, VAMP2, UNC5D), with CD74, SDC4 being found twice. The UNC5D is a novel fusion partner identified in prostate adenocarcinoma. There was no co-occurrence with the other tested fusions nor KRAS, BRAF, and the other gene mutations specified in the applied gene panels. Immunohistochemically, the focal expression of CK20 was present in 2 lung adenocarcinomas. We believe it should be considered as an incidental finding. In conclusion, the overall frequency of tumors with NRG1 fusion was 0.2%. All tumors were carcinomas. We confirm (invasive mucinous) lung adenocarcinoma as being the most frequent tumor presenting NRG1 fusion. Herein novel putative pathogenic gene fusion UNC5D-NRG1 is described. The potential role of immunohistochemistry in tumor identification should be further addressed.

Diagnostic Reliability, Accuracy and Safety of Ultrasound-guided Biopsy and Ascites Puncture in Primarily Inoperable Ovarian Tumours.

BACKGROUND/AIM: To compare the diagnostic reliability, accuracy and safety of ultrasound-guided biopsy (Tru-Cut biopsy) and ascites puncture in patients with a primarily inoperable malignant ovarian tumor. PATIENTS AND METHODS: This is a retrospective analysis of the studied methods in consecutively examined patients and a prospective validation of these methods. 79 women with a suspected primarily inoperable ovarian tumor underwent Tru-Cut biopsies and were included in the ultrasound-guided biopsy group. In addition, 55 patients after ascites puncture were enrolled in the comparison group. Both procedures were performed in 48 patients for the prospective validation. RESULTS: Significant differences in favour of ultrasound-guided biopsy were found in all studied variables (malignancy confirmation 72.9% vs. 95.8%, tumor origin 52.1% vs. 89.6%, histologic subtype 43.8% vs. 85.4% and accuracy, i.e. agreement of preoperative and definitive diagnosis 43.7% vs. 95.4%). CONCLUSION: Ultrasound-guided biopsy is an accurate, reliable, safe and minimally invasive method. Owing to the high reliability and accuracy, it has the capacity to replace ascites puncture with cytologic examination or a more invasive method (laparoscopy, laparotomy) for adequate tumor sampling.

The newly proposed International Endocervical Adenocarcinoma Criteria and Classification and its relevance to cervical cytology screening assessed in a prospective 2-year study of 118 cases.

BACKGROUND: It is generally acknowledged that interobserver variability for the histological diagnosis of endocervical adenocarcinoma (EA) subtypes is suboptimal. The recently proposed International Endocervical Adenocarcinoma Criteria and Classification (IECC) system is based on the presence of associated human papilloma virus (HPV) infection. It recognises HPV-associated EAs and non-HPV-associated EAs. METHODS: This prospective cytology-histology and molecular genetics-based study investigated the potential effect of IECC being applied to Papanicolaou (Pap) test with regard to the diagnostic accuracy of severe glandular lesions reported at least as adenocarcinoma in situ (AIS). RESULTS: Out of 118 liquid-based cytology Pap tests with AIS+ lesion, complete information on follow-up biopsy and HPV status was available in 51 cases. AIS and EA category correlated with histologically confirmed AIS/EA in 88.5% (23/26) and 70.5% (12/17) of cases, respectively. Interestingly, 93% (40/43) of cases diagnosed as AIS/EA were HPV positive and 7% (3/43) were HPV negative (originating in the cervix, endometrium and adnexa). CONCLUSIONS: Our findings suggest that this approach could possibly divide Pap tests containing severe glandular lesion into two groups: (a) robust diagnosis of HPV-associated EA and (b) non-HPV associated glandular lesions of heterogeneous origin, requiring further clinical preoperative diagnostic workup.

ZC3H7B-BCOR high-grade endometrial stromal sarcoma may present as myoma nascens with cytoplasmic signet ring cell change.

We report on 51-year-old woman who presented with brown discharge and postcoital bleeding due to myoma nascens-like polypoid mass distending cervical canal. Histologically, the tumor consisted of high-grade spindle cell component with up to 15 mitotic figures per 10 HPF and also low-grade leiomyoma-like areas with focal myxoid change and so far undescribed cytoplasmic signet ring cell change. Immunohistochemically Desmin, actin, and h-caldesmon were negative. Conversely, BCOR positive expression was coupled with Cyclin D1 positivity and was antibody clone dependent. The molecular NGS and FISH study identified reciprocal fusion gene ZC3H7B-BCOR. In conclusion, these findings further support the idea of routine reflex molecular testing of uterine mesenchymal tumors with unusual clinical presentation or in case malignancy is suspected. Lastly, we suggest ZC3H7B-BCOR rearranged high-grade endometrial stromal sarcoma might be considered as a tumor suitable for BCL6-targeted treatment.

Papillary renal cell carcinoma with prominent spindle cell stroma - tumor mimicking mixed epithelial and stromal tumor of the kidney: Clinicopathologic, morphologic, immunohistochemical and molecular genetic analysis of 6 cases.

Papillary renal cell carcinoma (PRCC) is currently a well-studied type of RCC. In addition to PRCC type 1, there are a number of other subtypes and variants of PRCCs which have been reported. We describe a series of 6 PRCCs with papillary, micropapillary and/or tubulopapillary architecture and prominent spindle cell stroma, resembling stroma in mixed epithelial and stromal tumor of the kidney (MESTK) or sarcomatoid RCC. Clinicopathologic, morphologic, immunohistochemical and molecular features were analyzed. All patients were males with an age range of 44-98 years (mean 65.3, median 65.5 years). Tumor size ranged from 2.4-11.4 cm (mean 5.8, median 4.5 cm). Follow-up data were available for 4 patients, ranging from 3 to 96 months (mean 42.75, median 36 months). Epithelial cells were mostly cylindrical with eosinophilic cytoplasm, showing nuclear grade 2 and 3 (ISUP/WHO). In all cases, loose to compact prominent stroma composed of spindle cells, without malignant mesenchymal heterologous elements was detected. No atypical mitoses were found, while typical mitoses were rare in both epithelial and stromal components. Epithelial cells were positive for CK7, AMACR, and vimentin in all cases, while negative for TFE3, HMB45, desmin, CD34, and actin. The stroma was positive for vimentin, actin and focally for CD34, while negative for CK7, AMACR, TFE3, HMB45, and desmin. Estrogen and progesterone receptors were completely negative. FH and SDHB expression was retained in all analyzable cases. Proliferative index was barely detectable in stromal component and low in epithelial component, ranging 0 to 5% positive stained cells/high power field. Copy number variation was variable with no distinct pattern. No mutations in CDKN2A, BAP1, MET were detected. PRCC with MESTK-like features is a distinct variant of PRCC mimicking MESTK. Our findings add to the body of literature on ever expanding variants of PRCCs. Both epithelial and stromal components lacked true Müllerian features, which was also proven by immunohistochemistry.

Inflammatory myofibroblastic tumor of the uterus - case report.

Inflammatory myofibroblastic tumor (IMT) of the uterus is rare but probably underdiagnosed tumor. It is usually benign but small fraction of cases may locally recur or rarely metastasize. Herein, we present a case report of 66-year-old patient with uterine IMT originally diagnosed as leiomyosarcoma of the uterus. The patient died within few months due to local tumor progression with skeletal metastases. Macroscopically, this was a voluminous locally aggressive yellowish-grey tumor of soft consistency limited to myometrium. Microscopically, the tumor was characterized by polymorphic spindle cell proliferation with marked nuclear atypia and numerous mitoses. Small geographic necroses was noticed. Typical histologic features of IMT were represented by lymphocytic infiltrate which was only very small and focal. Myxoid stroma was absent. Immunohistochemically, there was strong and diffuse cytoplasmic positivity of ALK (anaplastic lymphoma kinase). The presence of PPP1CB-ALK fusion transcript was confirmed by molecular-genetic methods. Proper diagnosis of uterine IMT is of importance as there is an option of targeted ALK inhibitor therapy in cases of aggressive tumor behaviour. Currently it is thought that histomorphology of uterine IMT may overlap with that of leiomyosarcoma and STUMP (smooth muscle tumor of uncertain malignant potential). The presence of ALK rearrangement is probably the only reliable diagnostic marker. Thus, ALK immunohistochemistry followed by molecular-genetic testing seems to represent suitable screening tool for the detection of uterine IMT.

Cytopathology of soft tissue tumors.

Nowadays, FNAC is an important diagnostic tool of soft tissue tumors in southeast Asia and India. We can also appreciate recent monographies on this topic authored by Swedish and American cytopathologists. They constantly stress the importance of clinical information and imaging studies. A cytology report should determine the morphological type of tumoral cell population, tumor grade (in two-tiered system) and conclusion providing at least some probable diagnostic options. This approach is documented in two case reports on pleiomorphic liposarcoma and giant cell tumor of tendo sheet.