Histopathology最新文献

Categorizing breast neoplasia as ductal or lobular is a daily exercise that relies on a combination of histologic and immunohistochemical tools. The historically robust link between loss of the E-cadherin molecule and lobular neoplasia has rendered staining for E-cadherin by immunohistochemistry a staple of this diagnostic process. Unfortunately, discordances between E-cadherin expression and histomorphology, and variations in E-cadherin staining patterns and intensities abound in clinical practice, but are often neglected in favour of a binary interpretation of the E-cadherin result. In this article, we highlight the complexities of E-cadherin expression through a review of the E-cadherin protein and its associated gene (CDH1), the mechanisms leading to aberrant/absent E-cadherin expression, and the implications of these factors on the reliability of the E-cadherin immunohistochemical stain in the classification of ductal versus lobular mammary neoplasia.

Aims: Contralateral axillary lymph node metastasis (CAM) is a rare clinical condition in patients with breast cancer (BC). CAM can be either a locoregional event or a distant metastasis. Molecular application for clonal evolution in BC has not been reported in CAM cases.

Methods: We studied six patients with CAM with clinical, pathological and/or molecular evidence of distant metastasis; those patients had poor outcomes.

Results: Two cases with molecular analysis of paired primary and CAM established clonal evolution of the CAM with its corresponding primary with additional molecular alteration, increased tumour mutation burden, and copy number variations (CNVs) in the CAMs. Four cases containing alterations from genes potentially modulate chromatin organization, supporting chromatin and subsequent transcriptional signature changes are essential in CAM. Molecular analysis is critical to establish the connection between CAM and its primary counterpart. Distant CAM shows clonal evolution compared with its corresponding primary with additional molecular alterations, increased mutation burden and/or copy number variations.

Conclusion: CAM should be evaluated individually and handled in a personalized fashion. Evidence of a true metastatic CAM can be supported by distant metastasis to other organs, specific morphological features and/or clonal evolution.

Aims: The PEComa family of tumours is defined by spindle/epithelioid cells with myomelanocytic differentiation. A small subset harbours TFE3 fusion; however, YAP1::TEE3 has not been reported. Clear cell stromal tumour of the lung (CCST-L) is an emerging entity characterized by spindle to epithelioid cells with focal cytoplasmic clearing, inflammatory infiltrates, no myomelanocytic differentiation, and YAP1::TFE3 fusion. Herein, we report two cases of lung tumours with myomelanocytic differentiation that showed inflammatory spindle cell histology, focal epithelioid clear cells, as well as YAP1::TFE3 fusion.

Methods and results: The patients were both men, aged 61 and 68 years. The tumours in both cases presented as well-circumscribed solid masses involving the lung hilum. After lobectomy, no recurrence was observed at 7 and 32 months. Both tumours shared storiform to short fascicular growth of long spindle cells, with a minor component of epithelioid cells showing clear cytoplasm in the background of substantial intratumoral chronic inflammation and dilated blood vessels. One tumour showed focal melanin deposition. Both tumours were immunohistochemically positive for HMB45, Melan A, and h-caldesmon. Fluorescence in situ hybridization assays indicated the presence of YAP1::TFE3 fusions, which was confirmed by RNA sequencing in one case tested, and by immunohistochemical TFE3 expression and loss of YAP1 C-terminus staining.

Conclusion: We present two cases of inflammatory spindle to epithelioid cell tumours of the lungs with myomelanocytic differentiation and YAP1::TFE3 fusion. This unique morphology and gene fusion suggest that these tumours may constitute a distinct subset of lung PEComa. Furthermore, morphological and molecular overlap with CCST-L gives rise to a hypothesis of a potential inherent relationship between PEComa and CCST-L.

Aims: CIC-rearranged sarcomas (CRS) are clinically aggressive undifferentiated round cell sarcomas (URCS), commonly driven by CIC::DUX4. Due to the repetitive nature of DUX4 and the variability of the fusion breakpoints, CIC::DUX4 fusion may be missed by molecular testing. Immunohistochemical (IHC) stains have been studied as surrogates for the CIC::DUX4 fusion. We aim to assess the performance of DUX4 IHC in the work-up of CRS and its expression in non-CRS round cell or epithelioid neoplasms.

Methods and results: Cases of molecularly confirmed CRS (n = 48) and non-CRS (n = 105) were included. CRS cases consisted of 35 females and 13 males, with ages ranging from less than 1 year to 67 years (median = 41 years). Among the molecularly confirmed non-CRS cases, C-terminal DUX4 expression was investigated in Ewing sarcomas (38 cases), alveolar rhabdomyosarcomas (18 cases), desmoplastic small round cell tumours (12 cases) and synovial sarcomas (n = five), as well as in non-mesenchymal neoplasms such as SMARCA4/SMARCB1-deficient tumours (n = five), carcinomas of unknown primary (n = three) and haematolymphoid neoplasms (four cases). DUX4 IHC was considered positive when strong nuclear expression was detected in more than 50% of neoplastic cells. When used as a surrogate for the diagnosis of CRS, the sensitivity and specificity of DUX4 IHC was 98 and 100%, respectively. Only one CRS case was negative for DUX4 IHC and harboured a CIC::FOXO4 fusion.

Conclusions: DUX4 IHC is a highly sensitive and specific surrogate marker for the presence of CIC::DUX4 fusion, demonstrating its utility in establishing a diagnosis of CRS.

Introduction and objectives: Fluorescence confocal microscopy (FCM) is a new imaging modality capable of generating digital microscopic resolution scans of fresh surgical specimens, and holds potential as an alternative to frozen section (FS) analysis for intra-operative assessment of surgical margins. Previously, we described the LaserSAFE technique as an application of FCM for margin assessment in robot-assisted radical prostatectomy (RARP) using the Histolog® scanner. This study describes the accuracy and inter-rater agreement of FCM imaging compared to corresponding paraffin-embedded analysis (PA) among four blinded pathologists for the presence of positive surgical margins (PSM).

Materials and methods: RARP specimens from patients enrolled in the control arm of the NeuroSAFE PROOF study (NCT03317990) were analysed from April 2022 to February 2023. Prostate specimens were imaged using the Histolog® scanner before formalin fixation and PA. Four trained assessors, blinded to PA, reviewed and analysed FCM images of the posterolateral prostatic surface.

Results: A total of 31 prostate specimens were included in the study. PA per lateral side of the prostate identified 11 instances of positive margins. Among the four histopathologists included in our study, FCM achieved a sensitivity of 73-91 and specificity of 94-100% for the presence of PSM. Fleiss' Kappa for inter-rater agreement on PSM was 0.78 (95% confidence interval = 0.64-0.92), indicating substantial agreement.

Conclusion: This blinded analysis of FCM versus PA among histopathologists with different experience levels demonstrated high accuracy and substantial inter-rater agreement for diagnosing PSM. This supports the role of the FCM as an alternative to FS.

Aims: Breast cancer with human epidermal growth factor receptor 2 (HER2) immunohistochemistry (IHC) 1+ or 2+ with negative in-situ hybridisation (ISH) (HER2-low) can now be targeted by HER2 antibody drug conjugates. We set out to compare HER2 status between matched primary invasive breast carcinoma (IBC) and distant metastases (DM) with clinical-pathological correlation, with specific interest in HER2-low.

Methods: Biomarker studies and clinical-pathological features of primary IBC with matched DM diagnosed between 2021 and 2022 were retrospectively analysed. HER2 status was assessed per 2023 American Society of Clinical Oncology/College of American Pathologists (ASCO/CAP) guidelines for IHC (4B5) and ISH (IQFISH pharmDX). Bilateral breast primaries were excluded. HER2 IHC 0 to 1+ were reassessed.

Results: One hundred and forty-seven cases of primary IBC with matched DM were identified. Biomarkers were performed on core biopsy (n = 74) and resection (n = 73). One hundred and twenty-six (86%) were initially classified as 'HER2-negative'; of these, 67 (46%) were reclassified as HER2-low. Patients with HER2-positive primaries were younger (P = 0.01) and had an increased incidence of micropapillary carcinoma (P = 0.02). HER2-low primaries also had an increased incidence of micropapillary carcinoma (P = 0.02) and oestrogen receptor (ER) positivity (P = 0.02) compared to HER2 0. One hundred and sixty-nine matched DM cases excluding bone metastasis were identified (range = one to seven metastases per IBC). The most common sites of metastases were liver (50 of 169, 30%), lung (36 of 169; 21%), distant lymph node (26 of 169, 15%); 138 DM cases (82%) were previously classified as 'HER2-negative', and 62 (37%) were reclassified as HER2-low. Like HER2-low primaries, HER2-low metastases were frequently ER-positive (52 of 62; 84%) (P = 0.02). Brain metastases were more frequently HER2-positive (five of 32; 16%) (P = 0.04). Comparing HER2 status in matched primaries and DM, HER2 status was discordant in 62 cases (37%). Most changes occurred from HER2-low to HER2 0 (33 of 169, 20%), HER2 0 to HER2-low (17 of 169, 10%) and HER2-low to positive (10 of 169, 6%). All HER2-low to HER2 0 changes were HER2 1+ to 0. In 30 patients with multiple DM sites (47 cases), HER2 status among different DM samples was discordant in 16 patients (53%), mainly from HER2-low to HER2 0 (16 of 47, 34%).

Conclusion: A significant proportion of previous 'HER2-negative' primaries and DM cases were reclassified as HER2-low. Discordant HER2 status between IBC primary and metastasis and between different DM sites demonstrated tumour heterogeneity and highlights the need for HER2 retesting in distant metastasis.

Aims: Although turmeric is commonly ingested and well tolerated, there is increasing evidence that over-the-counter turmeric supplements can cause drug-induced liver injury. We sought to thoroughly characterise clinicopathological features of patients for whom liver injury was attributed clinically to turmeric supplements.

Methods and results: We identified 11 patients via retrospective pathology archive review: 10 females (91%) and one male, with a median age of 58 years (range = 37-66 years). Six patients (55%) were asymptomatic with abnormal liver function tests, while five patients (45%) presented with malaise and/or jaundice. Ten patients (91%) showed predominant transaminase abnormalities, while one exhibited predominant alkaline phosphatase elevation. Histologically, biopsies showed acute hepatitis (eight cases, 73%, including five pan-lobular and three zone 3-predominant inflammation), scattered lobular aggregates of histiocytes (two; 18%) and a chronic hepatitis pattern of injury (one; 9%). Mild bile duct injury was present in five biopsies (45%). All patients stopped ingesting turmeric supplements after presenting with liver injury, and four patients additionally received steroid therapy; liver function tests normalised in all patients. Roussel Uclaf causality assessment method (RUCAM) analysis estimated the likelihood of turmeric supplement-associated liver injury to be probable (eight cases) and possible (three).

Conclusions: Histological features in the 'possible' cases were consistent with drug-induced injury, highlighting the added benefit of histological analysis relative to RUCAM analysis isolation. This study underscores the need to obtain a full history of over-the-counter medications and supplements when investigating aetiologies for liver injury, including supplements purportedly containing innocuous compounds such as turmeric.

Aims: Diagnosis of coeliac disease (CD) with mild mucosal changes is difficult for all parties involved. We aimed to determine the power of T cell receptor (TCR)γδ⁺ intra-epithelial lymphocytes (IELs) in discriminating CD from other causes of intra-epithelial lymphocytosis using a new monoclonal antibody.

Methods: A total of 167 cases categorised as coeliac (117 untreated CD, classified according to Marsh, updated by Ensari, including 29 type 1, 29 type 2, 39 type 3 and 20 treated CD), and non-coeliac groups (24 controls and 26 non-coeliac IELosis) based on clinical, serological and histological data were studied for IEL counts enumerated per 100 enterocytes using haematoxylin and eosin, CD3, TCR δ-stains.

Results: TCRγδ⁺ IELs were significantly higher in CD (24.83 ± 16.13) compared to non-CD (6.72 ± 6.32) and were correlated with the degree of mucosal damage. Both γδ⁺ IEL count and ratio showed higher performance in differentiating untreated coeliacs from controls, with a sensitivity of 83.76; 85.57 and specificity of 95.83; 79.17, respectively. TCRγδ⁺ IEL counts distinguished type 1 CD (20.41 ± 13.57) from non-coeliac IELosis (9.42 ± 7.28) (p = 0.025). Discriminant analysis revealed that villus/crypt ratio, γδ⁺ and CD3⁺ IEL counts, γδ⁺/CD3⁺IEL ratio, IEL distribution pattern were potent discriminants and correctly classified 82.3% of cases while the algorithm accurately diagnosed 93.4% of cases.

Conclusions: The new antibody detecting γδ⁺ IELs in FFPE sections revealed thresholds of 10.5 for γδ⁺ IELs and 14% for γδ⁺/CD3⁺IEL ratio which distinguished coeliacs from non-coeliacs with high sensitivity and specificity, particularly in cases with normal villus/crypt axis including type 1 CD, non-CD IELosis and controls. A 'coeliac algorithm' based on γδ⁺ IELs is proposed with the hope that it will be used in the histopathological diagnostic approach by the pathology community.