T regulatory lymphocytes specific for SARS-CoV-2 display increased functional plasticity.

The study of phenotypic and functional characteristics of immune cells involved in host response to SARS-CoV-2 is relevant for understanding COVID-19 pathogenesis and individual differences in disease progression. We have analyzed chemokine receptor expression in SARS-CoV-2-specific CD4+ T lymphocytes from vaccinated donors, and have found an increase of CCR9+ and CCR6+ cells. CCR9+ specific CD4+ cells are enriched in T regulatory (Treg) lymphocytes. These cells specifically show heterogeneous regulatory activity, associated with different profiles of CCR9/CCR6 expression, individual differences in IL-10 and IL-17 production, and variable FoxP3 and Notch4 expression. A higher heterogeneity in FoxP3 is selectively observed in convalescent individuals within vaccinated population. Accordingly, SARS-CoV-2-specific CD4+ lymphocytes from COVID-19 patients are also enriched in CCR9+ and CCR6+ cells. CCR6+ specific Treg lymphocytes are mainly increased in critically ill individuals, indicating a preferential role for these cells in lung injury pathogenesis. We provide experimental evidence for a SARS-CoV-2-specific Treg population with increased plasticity, which may contribute to the differential pathogenic response against SARS-CoV-2 among individuals, and underlie the development of autoimmune conditions following SARS-CoV-2 infection.

Immune-related gene expression signatures: a step forward in the stratification of patients with ovarian clear cell carcinoma†.

Clear cell carcinoma of the ovary (CCC) is one of the five major histological types of ovarian cancer and presents specific clinicopathological features, such as a higher prevalence in the Asian population and a poor response to conventional chemotherapy. In a recent publication in The Journal of Pathology, Heong, Tan, Miwa et al demonstrated the heterogeneity of the immune landscape of CCC. They reported the immune signatures observed in a large cohort of CCC, including tumours from both Asian and Caucasian women. The authors analysed three cohorts from Europe, Japan, and Singapore, with a total of 246 tumours, and evaluated 730 immune-related genes using NanoString technology. The study revealed four main transcriptional subtypes characterised by the expression of specific sets of genes: PD1-high (11%), CTLA4-high (29%), antigen-presentation (42%), and a pro-angiogenic subtype (18%). The two main conclusions of the study were: (1) that CCCs in women of Asian and Caucasian descent share significant molecular similarities, since all four molecular signatures are present in all the cohorts analysed, without any evident differences in frequency; and (2) that the PD1-high and CTLA4-high subtypes were associated with worse clinical outcomes and may be useful when stratifying treatment in early-stage tumours. The immune signature could represent a promising biomarker of immunotherapy response if future prospective studies confirm it. © 2021 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Extramammary Paget Disease: a Therapeutic Challenge, for a Rare Entity.

PURPOSE OF REVIEW: Extramammary Paget disease (EMPD) is a rare entity which is more frequently localized at the vulva, though it only accounts for 1-2% of vulvar neoplasms. It is a primary cutaneous adenocarcinoma whose cell of origin is still a matter of controversy: it can either arise from apocrine/eccrine glands or from stem cells. The diagnosis demands a biopsy and entails a histopathological analysis by which cells show similar characteristics as breast Paget disease. RECENT FINDINGS: Treatment approach can entail surgery, radiotherapy, photodynamic therapy, systemic chemotherapy, and topical chemotherapy. For metastatic disease, many different chemotherapy regimens have been explored and even targeted therapy can play an important role in this disease. Since almost 30-40% of patients overexpress HER-2, trastuzumab and anti-HER-2 therapies can be employed in this setting. Due to its low incidence, there is almost no specific evidence on therapeutic interventions for this disease. Thus, there is a neat unmet need for molecular characterization of EMPD and diagnostic tools that allow clinicians to guide treatment both in the early and in the advanced disease settings. In this review, we aim to summarize available evidence about diagnosis and treatment of EMPD, both localized and metastatic, and to provide a comprehensive analysis that may help clinicians for therapeutic decisions.

The Prognostic Significance of Tumor-Infiltrating Lymphocytes, PD-L1, BRCA Mutation Status and Tumor Mutational Burden in Early-Stage High-Grade Serous Ovarian Carcinoma-A Study by the Spanish Group for Ovarian Cancer Research (GEICO).

Early stages are under-represented in studies on the molecular and immune features of high-grade serous ovarian carcinoma (HGSOC), and specific studies focused on early-stage HGSOC are required for a better prognostic stratification and to personalize chemotherapy. The aim of this study was to determine the prognostic significance of CD8+ and CD4+ tumor-infiltrating lymphocytes (TILs), tumoral cell PD-L1 expression, BRCA mutational status and tumor mutation burden (TMB) in early-stage HGSOC. A retrospective study was performed on stage I and II HGSOC from the Molecular Reclassification of Early Stages of Ovarian Cancer (RECLAMO) cohort from the Spanish Group of Ovarian Cancer Research (GEICO). Centralized histological typing was performed based on morphological and immunohistochemical features. Intraepithelial (i) and stromal (s) CD8+ and CD4+ T cells and PD-L1 were evaluated on tissue microarrays by immunohistochemistry. BRCA1 and BRCA2 mutation status and TMB were analyzed in tumor DNA using next-generation sequencing. The study included 124 tumors. High iCD8+ (>20 TILs/core), low/intermediate CD4+ (<20 TILs/core) and high CD8+/CD4+ ratio (>35/core) were associated with favorable outcomes. Tumor cell PD-L1 expression (TPS ≥ 1) was present in only 8% of tumors. In total, 11 (16%) and 6 (9%) out of 69 HGSOC tested carried pathogenic or likely pathogenic BRCA1 or BRCA2 mutations, respectively. Median TMB of 40 tumors analyzed was 5.04 mutations/Mb and only 6 tumors had 10 or more mutations/Mb. BRCA status and TMB were not associated with TILs or prognosis. When compared with studies on advanced HGSOC, our results suggested that prognostic variables differed according to stage and that more studies focused on early stages of HGSOC are needed to better stratify these tumors.

Pulmonary vascular proliferation in patients with severe COVID-19: an autopsy study.

Diffuse alveolar damage and thrombi are the most common lung histopathological lesions reported in patients with severe COVID-19. Although some studies have suggested increased pulmonary angiogenesis, the presence of vascular proliferation in COVID-19 lungs has not been well characterised. Glomeruloid-like microscopic foci and/or coalescent vascular proliferations measuring up to 2 cm were present in the lung of 14 out of 16 autopsied patients. These lesions expressed CD31, CD34 and vascular endothelial cadherin. Platelet-derived growth factor receptor-ß immunohistochemistry and dual immunostaining for CD34/smooth muscle actin demonstrated the presence of pericytes. These vascular alterations may contribute to the severe and refractory hypoxaemia that is common in patients with severe COVID-19.

Vulvar Pilomatrix Carcinoma: Morphologic and Molecular Features.

Pilomatrix carcinoma (PC) is a rare malignant variant of pilomatrixoma, a skin adnexal tumor originating from hair matrix cells. It is most often located in the head, neck region, upper back and upper extremities. PC has a locally aggressive behavior but metastasis only occur in 10% of cases. Mutations in CTNNB1, the encoding gene of beta-catenin, have been found in both pilomatrixoma and PC, but other molecular alterations are unknown. The authors present a case of PC in the clitoris, the third known reported case located on the external genitalia. The tumor followed an unusual clinical course with the development of multiple metastases. Next-generation sequencing analysis of the tumor identified, in addition to a characteristic CTNNB1 mutation, pathogenic mutations in PTEN, PIK3CA, and ARID1A, which could explain the aggressive course of the disease. The diagnostic criteria of PC and the differential diagnoses of this unusual tumor in the genital area are discussed.

Epithelial Mesenchymal Transition and Immune Response in Metaplastic Breast Carcinoma.

Metaplastic breast carcinoma (MBC) is a heterogeneous group of infrequent triple negative (TN) invasive carcinomas with poor prognosis. MBCs have a different clinical behavior from other types of triple negative breast cancer (TNBC), being more resistant to standard chemotherapy. MBCs are an example of tumors with activation of epithelial-mesenchymal transition (EMT). The mechanisms involved in EMT could be responsible for the increase in the infiltrative and metastatic capacity of MBCs and resistance to treatments. In addition, a relationship between EMT and the immune response has been seen in these tumors. In this sense, MBC differ from other TN tumors showing a lower number of tumor-infiltrating lymphocytes (TILS) and a higher percentage of tumor cells expressing programmed death-ligand 1 (PD-L1). A better understanding of the relationship between the immune system and EMT could provide new therapeutic approaches in MBC.

Molecular genetic heterogeneity in undifferentiated endometrial carcinomas.

Undifferentiated and dedifferentiated endometrial carcinomas are rare and highly aggressive subtypes of uterine cancer, not well characterized at a molecular level. To investigate whether dedifferentiated carcinomas carry molecular genetic alterations similar to those of pure undifferentiated carcinomas, and to gain insight into the pathogenesis of these tumors, we selected a cohort of 18 undifferentiated endometrial carcinomas, 8 of them with a well-differentiated endometrioid carcinoma component (dedifferentiated endometrioid carcinomas), and studied them by immunohistochemistry and massive parallel and Sanger sequencing. Whole-exome sequencing of the endometrioid and undifferentiated components, as well as normal myometrium, was also carried out in one case. According to The Cancer Genome Atlas classification, we distributed 95% of the undifferentiated carcinomas in this series as follows: (a) hypermutated tumors with loss of any mismatch repair protein expression and microsatellite instability (eight cases, 45%); (b) ultramutated carcinomas carrying mutations in the exonuclease domain of POLE (two cases, 11%); (c) high copy number alterations (copy-number high) tumors group exhibiting only TP53 mutations and high number of alterations detected by FISH (two cases, 11%); and (d) low copy number alterations (copy-number low) tumors with molecular alterations typical of endometrioid endometrial carcinomas (five cases, 28%). Two of the latter cases, however, also had TP53 mutations and higher number of alterations detected by FISH and could have progressed to a copy-number high phenotype. Most dedifferentiated carcinomas belonged to the hypermutated group, whereas pure undifferentiated carcinomas shared molecular genetic alterations with copy-number low or copy-number high tumors. These results indicate that undifferentiated and dedifferentiated endometrial carcinomas are molecularly heterogeneous tumors, which may have prognostic value.

Biomarkers in breast cancer 2024: an updated consensus statement by the Spanish Society of Medical Oncology and the Spanish Society of Pathology.

This revised consensus statement of the Spanish Society of Medical Oncology (SEOM) and the Spanish Society of Pathological Anatomy (SEAP) updates the recommendations for biomarkers use in the diagnosis and treatment of breast cancer that we first published in 2018. The expert group recommends determining in early breast cancer the estrogen receptor (ER), progesterone receptor (PR), Ki-67, and Human Epidermal growth factor Receptor 2 (HER2), as well as BReast CAncer (BRCA) genes in high-risk HER2-negative breast cancer, to assist prognosis and help in indicating the therapeutic options, including hormone therapy, chemotherapy, anti-HER2 therapy, and other targeted therapies. One of the four available genetic prognostic platforms (Oncotype DX®, MammaPrint®, Prosigna®, or EndoPredict®) may be used in ER-positive patients with early breast cancer to establish a prognostic category and help decide with the patient whether adjuvant treatment may be limited to hormonal therapy. In second-line advanced breast cancer, in addition, phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and estrogen receptor 1 (ESR1) should be tested in hormone-sensitive cases, BRCA gene mutations in HER2-negative cancers, and in triple-negative breast cancer (TNBC), programmed cell death-1 ligand (PD-L1). Newer biomarkers and technologies, including tumor-infiltrating lymphocytes (TILs), homologous recombination deficiency (HRD) testing, serine/threonine kinase (AKT) pathway activation, and next-generation sequencing (NGS), are at this point investigational.

CDH1 methylation analysis in invasive lobular breast carcinomas with and without gene mutation.

The proposed role of CDH1 (E-cadherin gene) methylation as a mechanism of gene inactivation in invasive lobular carcinoma (ILC) remains inconclusive. For many years, CDH1 promoter hypermethylation has been regarded as a mechanism for gene inactivation in ILC. However, this assumption has primarily relied on non-quantitative assays, which have reported CDH1 methylation frequencies ranging from 26 to 93% at CpG sites within the island region. Few studies employing quantitative methods and covering CpG island shores, regions of relatively low CpG density situated proximal to conventional promoter CpGs, have been conducted, revealing lower percentages of methylation ranging from 0 to 51%. Therefore, using the quantitative pyrosequencing method, we examined CDH1 methylation in the island region and shores in E-cadherin deficient ILC cases (15 with CDH1 mutation and 22 non-mutated), 19 cases of invasive breast carcinomas non-special type (IBC-NSTs), and five cases of usual ductal hyperplasia (UDH). Our analysis revealed CDH1 methylation frequencies ranging from 3 to 64%, with no significant increase in methylation levels in any group of ILCs (median = 12%) compared to IBC-NST (median = 15%). In addition, considering the poorly studied association between the number of tumor-infiltrating lymphocytes (TILs) and CDH1 methylation in breast cancer, we undertook a thorough analysis within our dataset. Our findings revealed a positive correlation between CDH1 methylation and the presence of TILs (r = 0.5; p-value < 0.05), shedding light on an aspect of breast cancer biology warranting further investigation. These findings challenge CDH1 methylation as a CDH1 inactivation mechanism in ILC and highlight TILs as a potential confounding factor in gene methylation.

Contribution of Outpatient Ultrasound Transvaginal Biopsy and Puncture in the Diagnosis and Treatment of Pelvic Lesions: A Bicenter Study.

BACKGROUND: The use of transvaginal ultrasound guided biopsy and puncture of pelvic lesions is a minimally invasive technique that allows for accurate diagnosis. It has many advantages compared to other more invasive (lower complication rate) or non-invasive techniques (accurate diagnosis). Furthermore, it offers greater availability, it does not radiate, enables the study of pelvic masses accessible vaginally with ultrasound control in real time, and it is possible to use the colour Doppler avoiding puncturing large vessels among others. The main aim of the work is to describe a standardized ambulatory technique and to determine its usefulness. METHODS: This is a retrospective study of ultrasound transvaginal punctures (core needle biopsies and cytologies) and drainages of pelvic lesions performed on an outpatient basis during the last two years. The punctures were made with local anesthesia, under transvaginal ultrasound guidance with an automatic or semi-automatic 18G biopsy needle with a length of 20-25 cm and a penetration depth of 12 or 22 mm. The material obtained was sent for anatomopathological, cytological and/or microbiological study if necessary. RESULTS: A total of 42 women were recruited in two centers. Fifty procedures (nine punctures, seven drains, and 34 biopsies) were performed. In five cases the punction and drain provided clinical relief in benign pelvic masses. Regarding material of the biopsies performed, 15 were vaginal in women previously histerectomized, finding 10 carcinomas, eight were ovarian tumours in advanced stages or peritoneal carcinomatosis obtaining the appropriate histology in each case, seven were suspicious cervical biopsies finding carcinomas in five of them, three were myometrial biopsies including one breast carcinoma metastasis in the miometrium and a benign placental nodule, and a periurethral biopsy was performed on a woman with a history of endometrial cancer confirming recurrence. The pathological diagnosis was satisfactory in all cases, confirming the nature of the lesion (25 malignant-ten vaginal recurrences of previous gynaecological cancers, eight cases of primary ovarian/peritoneal carcinoma, four new diagnosis of cervical malignant masses, one cervical metastasis of lymphoma, one periurethral recurrence of endometrial carcinoma and one recurrence of breast cancer in the myometrium-and 23 benign). The tolerance was excellent and no complications were detected. CONCLUSION: The ambulatory ultrasound transvaginal puncture and drainage technique is useful for obtaining a sample for pathological and microbiological diagnosis with excellent tolerance that can be used to rule out the recurrence of malignant lesions or progression of the disease, diagnose masses not accessible to gynecological exploration (vaginal vault, myometrium or cervix) and for early histologic diagnosis in cases of advanced peritoneal carcinomatosis or ovarian carcinoma as well as drainage and cytological study of cystic pelvic masses.

Tumor P70S6K hyperactivation is inversely associated with tumor-infiltrating lymphocytes in triple-negative breast cancer.

PURPOSE: Triple-negative breast cancer (TNBC) is characterized by large heterogeneity and relative lack of available targeted therapies. To find therapeutic strategies for distinct patients with TNBC, several approaches have been used for TNBC clustering, including recently immune and phosphoproteomic patterns. Based on 70-kDa ribosomal protein S6 kinase (P70S6K)-TNBC clustering, the current study explores the immune profiling in TNBC tumors. METHODS: Stromal tumor-infiltrating lymphocytes (sTILs) were evaluated in human TNBC tumor samples. Furthermore, immunohistochemistry staining for CD8, CD4, Foxp3, and CD20 was performed in tissue microarrays (TMA) sections. RESULTS: Histological analysis showed decreased sTILs, CD20+ cells, and CD8+/CD4+ ratio in high phosphorylated P70S6K (p-P70S6K) tumors. Moreover, p-P70S6K score was directly correlated with CD4+ and Foxp3+ T cells, while it was inversely correlated with CD8+/CD4+ and CD8+/Foxp3+ ratios. CONCLUSION: sTIL infiltration and lymphocyte profiling vary in the context of hyperactivation of P70S6K in TNBC tumors.

Evaluation of ERBB2 mRNA Expression in HER2-Equivocal (2+) Immunohistochemistry Cases.

Xpert Breast Cancer STRAT4 is a RT-qPCR platform that studies the mRNA expression of ESR1, PGR, MKI67 and ERBB2, providing a positive or negative result for each of these breast cancer biomarkers. Its concordance with immunohistochemistry (IHC) and in situ hybridization (ISH) has been previously demonstrated, but none of the previous works was focused on HER2-equivocal (2+) cases identified by IHC. Thus, we studied the concordance between IHC/ISH and STRAT4 results for 112 HER2 2+ IBC samples, using 148 HER2 0+, 1+ and 3+ (no-HER2 2+) samples for comparison. We found 91.3% accuracy for the determination of HER2 status globally, 99.3% for no-HER2 2+ samples and 80.7% for HER2 2+ samples. Regarding the other biomarkers, we obtained 96.4% accuracy for estrogen receptor, 84.1% for progesterone receptor and 58.2% for Ki67. Our results suggest that the use of ERBB2 mRNA for the evaluation of HER2 2+ cases is not a reliable reflex method to assess the ERBB2 amplification status.

Application of Ultrasound Scores (Subjective Assessment, Simple Rules Risk Assessment, ADNEX Model, O-RADS) to Adnexal Masses of Difficult Classification.

BACKGROUND: Ultrasound features help to differentiate benign from malignant masses, and some of them are included in the ultrasound (US) scores. The main aim of this work is to describe the ultrasound features of certain adnexal masses of difficult classification and to analyse them according to the most frequently used US scores. METHODS: Retrospective studies of adnexal lesions are difficult to classify by US scores in women undergoing surgery. Ultrasound characteristics were analysed, and masses were classified according to the Subjective Assessment of the ultrasonographer (SA) and other US scores (IOTA Simple Rules Risk Assessment-SRRA, ADNEX model with and without CA125 and O-RADS). RESULTS: A total of 133 adnexal masses were studied (benign: 66.2%, n:88; malignant: 33.8%, n:45) in a sample of women with mean age 56.5 ± 7.8 years. Malignant lesions were identified by SA in all cases. Borderline ovarian tumors (n:13) were not always detected by some US scores (SRRA: 76.9%, ADNEX model without and with CA125: 76.9% and 84.6%) nor were serous carcinoma (n:19) (SRRA: 89.5%), clear cell carcinoma (n:9) (SRRA: 66.7%) or endometrioid carcinoma (n:4) (ADNEX model without CA125: 75.0%). While most teratomas and serous cystadenomas have been correctly differentiated, other benign lesions were misclassified because of the presence of solid areas or papillae. Fibromas (n:13) were better identified by SA (23.1% malignancy), but worse with the other US scores (SRRA: 69.2%, ADNEX model without and with CA125: 84.6% and 69.2%, O-RADS: 53.8%). Cystoadenofibromas (n:10) were difficult to distinguish from malignant masses via all scores except SRRA (SA: 70.0%, SRRA: 20.0%, ADNEX model without and with CA125: 60.0% and 50.0%, O-RADS: 90.0%). Mucinous cystadenomas (n:12) were misdiagnosed as malignant in more than 15% of the cases in all US scores (SA: 33.3%, SRRA: 16.7%, ADNEX model without and with CA125: 16.7% and 16.7%, O-RADS:41.7%). Brenner tumors are also difficult to classify using all scores. CONCLUSION: Some malignant masses (borderline ovarian tumors, serous carcinoma, clear cell carcinoma, endometrioid carcinomas) are not always detected by US scores. Fibromas, cystoadenofibromas, some mucinous cystadenomas and Brenner tumors may present solid components/papillae that may induce confusion with malignant lesions. Most teratomas and serous cystadenomas are usually correctly classified.

Breast metastases from non-primary breast malignancies: What should we know?

BACKGROUND: Metastases from extramammary malignant neoplasms are very rare, accounting for less than 2% of all breast malignancies. OBJECTIVE: The aim of this study is to describe the clinicopathological features and prognosis of breast metastases from non-primary breast malignancies at our institution. METHODS: We performed a retrospective observational study, obtaining data from electronic medical records and pathology databases between January 1985 and December 2020 for patients diagnosed with breast metastasis from non-primary breast malignancies. Only patients diagnosed by biopsy were included. RESULTS: Fifteen patients diagnosed with breast metastases from non-primary breast malignancies were included, 13 women (86,67%) and 2 men (13,33%). The median age at time of initial diagnosis was 56 years (IQR 21-68). The most frequent primary malignancy was melanoma (9/15; 60%). The median time to diagnosis of breast metastases was 65 months (IQR 13-106). The most common diagnostic modality was CT-scan (10/15; 66,67%). The median follow-up was 96 months (IQR 29-136). Eight patients underwent surgery (53,3%), being the most common surgical intervention breast-conserving surgery (5/8; 62,5%). Mortality at the end of follow-up was 53,3% (8/15). On the survival analysis, we found no differences between patients undergoing surgery and those only receiving systemic treatment [41,5 months (IQR 17,5-57,5) versus 14 months (IQR 2-24), respectively; p = 0,161]. CONCLUSIONS: Breast metastases from non-primary breast malignancies are extremely rare and represent a diagnostic and therapeutic challenge, due to the poor prognosis of these patients. Thus, arriving at the correct diagnosis is crucial to avoid unnecessary treatment in this population.

Post-mortem findings in Spanish patients with COVID-19; a special focus on superinfections.

Introduction: Whole-body autopsies may be crucial to understand coronavirus disease 2019 (COVID-19) pathophysiology. We aimed to analyze pathological findings in a large series of full-body autopsies, with a special focus on superinfections. Methods: This was a prospective multicenter study that included 70 COVID-19 autopsies performed between April 2020 and February 2021. Epidemiological, clinical and pathological information was collected using a standardized case report form. Results: Median (IQR) age was 70 (range 63.75-74.25) years and 76% of cases were males. Most patients (90%,) had at least one comorbidity prior to COVID-19 diagnosis, with vascular risk factors being the most frequent. Infectious complications were developed by 65.71% of the patients during their follow-up. Mechanical ventilation was required in most patients (75.71%) and was mainly invasive. In multivariate analyses, length of hospital stay and invasive mechanical ventilation were significantly associated with infections (p = 0.036 and p = 0.013, respectively). Necropsy findings revealed diffuse alveolar damage in the lungs, left ventricular hypertrophy in the heart, liver steatosis and pre-infection arteriosclerosis in the heart and kidneys. Conclusion: Our study confirms the main necropsy histopathological findings attributed to COVID-19 in a large patient series, while underlining the importance of both comorbid conditions and superinfections in the pathology.

Cytological and molecular characterization of secretory breast carcinoma.

Secretory breast carcinoma is a rare neoplasm, histologically well-characterized, and secondary to ETV6-NTRK3 gene fusion, whose cytological features are scarcely described in the literature. We report the case of a woman with a history of secretory breast carcinoma 8 years before, who presented a periareolar nodule. A recurrence was diagnosed by fine-needle aspiration based on the cytomorphological features and pan-TRK immunocytochemistry on the cell block, and the patient underwent a mastectomy. The histology and molecular studies performed on the surgical specimen (immunohistochemistry, FISH and NGS) confirmed the diagnosis. Cytological smears showed abundant epithelial cellularity, in groups and single cells. These cells showed moderate atypia, with abundant cytoplasm. We observed intracytoplasmic inclusions and extracellular metachromatic globules. Immunocytochemical and immunohistochemical studies showed a triple negative breast tumour. NTRK overexpression was demonstrated with immunocytochemistry against pan-TRK on the cell block, as well as with immunohistochemistry in the surgical specimen. NTRK3 rearrangement was proved by FISH. In the primary tumour and in the recurrence, we demonstrated ETV6-NTRK3 fusion by NGS. After conducting a literature review, we have found 26 articles describing the cytological features of secretory breast carcinoma in 33 patients. The smears were described as groups of epithelial cells with vacuolated cytoplasm, single signet ring cells and a globular extracellular secretion. In only two cases molecular confirmation of the diagnosis with ETV6-NTRK3 fusion was proven, although not in the cytological specimen, but in the subsequent biopsy. The distinct cytological features of secretory breast carcinoma can help in its diagnosis, thus guiding the molecular studies. This is the first reported case that proves TRK overexpression, as a fusion surrogate, in the cytological sample.

Impact of the COVID-19 pandemic on pathology training: a survey among Spanish residents.

This study aimed to assess the impact of the COVID-19 pandemic on the training of Spanish pathology residents by conducting an online survey. It was distributed among the pathologists who had been residents during the pandemic and consisted of 31 questions about the demographics and the impact of the pandemic on their pathology training. In total, 114 residents completed the survey; they reported a decrease in the number of biopsies, cytology samples, autopsies, research activities, sessions, case corrections, and courses, as well as the detrimental effect this had on their training. Half of the residents had to cancel rotations and 32% were redeployed to other departments. The COVID-19 pandemic has affected pathology training, and our results can be used to understand the challenges residents have faced and mitigate their impact.

The Clonal Relationship Between the Ductal and Lobular Components of Mixed Ductal-Lobular Carcinomas Suggested a Ductal Origin in Most Tumors.

The relationship between the ductal and lobular components of invasive ductolobular carcinomas (IDLC) has not been fully elucidated. In this study, the molecular alterations of both components were analyzed in a series of 20 IDLC that were selected, not only by morphologic criteria, but also by the loss of E-cadherin expression in the lobular component. We found that 80% of tumors shared alterations of driver genes in both components, being PIK3CA the most common alteration. In addition, 45% of IDLC carried CDH1 mutations in their lobular component that were absent in the ductal component. Fluorescent in situ hybridization analysis of the CDH1 gene excluded homozygous CDH1 loss as a frequent cause of E-cadherin loss in tumors without CDH1 mutations. In addition, no pathogenic mutations of catenin genes were detected in this series of tumors. In 25% of tumors, actionable mutations in PIK3CA , AKT1 , and ERBB2 were found in only 1 component. Altogether, our results confirm that most IDLC derive from invasive carcinoma of no special type, in which a population of cells lose E-cadherin and acquire a lobular phenotype. The frequency of CDH1 mutations in IDLC appears to be lower than in conventional invasive lobular carcinomas, suggesting the implication of alternative mechanisms of E-cadherin loss. Moreover, molecular heterogeneity between ductal and lobular areas suggests the need for molecular characterization of both components to guide targeted therapies.