Immunohistochemical Profile Research Articles

The utility of the lineage specific immunohistochemical stains SATB2, CDX2, and villin, and the mucin glycoproteins MUC2, MUC5AC, and MUC6 to distinguish pulmonary invasive mucinous adenocarcinoma from metastatic colorectal carcinoma

ContextThe lungs are a common site of tumor metastasis. While morphology and immunophenotype can help differentiate primary from metastatic tumors, distinguishing pulmonary invasive mucinous adenocarcinoma (PIMA) from metastatic colorectal adenocarcinoma (CRC) may occasionally be challenging due to overlapping morphological and immunohistochemical features. Lineage-specific markers such as CDX2, TTF-1, and napsin A are helpful with pulmonary non-mucinous adenocarcinoma (PNMA), however they are non-specific and insensitive when applied to PIMA. SATB2 is a newer marker that distinguishes CRC from upper gastrointestinal and pancreaticobiliary tumors; its utility in distinguishing CRC from PIMA has not been fully elucidated. ObjectiveTo evaluate the performance of lineage-specific and mucin glycoprotein immunostains in distinguishing PIMA and CRC. DesignWe stained tissue microarrays comprising 34 PNMA, 31 PIMA, and 32 CRC with CK7, CK20, SATB2, CDX2, villin, TTF-1, napsin A, and gel-forming mucins MUC2, MUC5AC, and MUC6. ResultsPIMA showed significant (>50% of cells) expression of SATB2 (6%), CDX2 (6%), villin (74%), TTF-1 (13%), and napsin A (23%). However, significant CK7 expression was seen in nearly all PIMA (30/31) and none of the metastatic CRC. ConclusionOur results suggest that CK7 remains one of the most useful markers for distinguishing primary PIMA from metastatic CRC. Expression of the mucin glycoproteins MUC5AC and MUC6 and lack of expression of MUC2 favored a diagnosis of PIMA, but expression of these markers was too heterogeneous to be of clinical utility. To our knowledge this is the only study comparing the immunohistochemical profile of PIMA and metastatic CRC in lung metastasectomy specimens.

Spindle cell carcinoma of the lower lip: A case report and review of the literature

To document the lip as an unusual site of clinical presentation of spindle cell carcinoma and to conduct a review of the literature. A 66-year-old male patient presented with an ulcerated lesion of the lower lip. Morphological examination and immunohistochemical profiling of the lesion were performed.

From Proliferation to Protection: Immunohistochemical Profiling of Cardiomyocytes and Immune Cells in Molly Fish Hearts

Unlike adult mammalian cardiomyocytes, cardiomyocytes in teleosts display high proliferative capacity throughout adulthood. This study aimed to identify the immunohistochemical profiles of cardiomyocytes and immune cells in the hearts of Molly fish by assessing the immunolabelling expression of key proteins involved in cell proliferation, differentiation, and tissue protection. The cardiac anatomy of Molly fish includes the atrium, ventricle, and bulbus arteriosus. The expression of SOX9, NF-κB, myostatin, and S100 proteins in myocardial cells indicates the proliferative features of the heart in Molly fish. The bulbus arteriosus is characterized by collagenous chambers and smooth muscle cells that express Ach and iba1. The atrium of Molly fish serves as a storage unit for rodlet cells and immune cells. Rodlet cells displayed immunoreactivity to NF-κB, iba1, Olig2, Ach, and S100 proteins, suggesting their roles in the immune response within the heart. Furthermore, telocytes (TCs) have emerged as a significant component of the atrium of Molly fish, expressing Ach, CD68, S100 protein, and iba1. These expressions indicate the involvement of TCs in multiple signaling pathways that contribute to heart architecture. This study delineates the intricate relationship between cardiomyocytes and innate immune cells in Molly fish.

Hydrogel-chitosan and polylactic acid-polycaprolactone bioengineered scaffolds for reconstruction of mandibular defects: a preclinical in vivo study with assessment of translationally relevant aspects.

Background: Reconstruction of mandibular bone defects is a surgical challenge, and microvascular reconstruction is the current gold standard. The field of tissue bioengineering has been providing an increasing number of alternative strategies for bone reconstruction. Methods: In this preclinical study, the performance of two bioengineered scaffolds, a hydrogel made of polyethylene glycol-chitosan (HyCh) and a hybrid core-shell combination of poly (L-lactic acid)/poly ( -caprolactone) and HyCh (PLA-PCL-HyCh), seeded with different concentrations of human mesenchymal stromal cells (hMSCs), has been explored in non-critical size mandibular defects in a rabbit model. The bone regenerative properties of the bioengineered scaffolds were analyzed by in vivo radiological examinations and ex vivo radiological, histomorphological, and immunohistochemical analyses. Results: The relative density increase (RDI) was significantly more pronounced in defects where a scaffold was placed, particularly if seeded with hMSCs. The immunohistochemical profile showed significantly higher expression of both VEGF-A and osteopontin in defects reconstructed with scaffolds. Native microarchitectural characteristics were not demonstrated in any experimental group. Conclusion: Herein, we demonstrate that bone regeneration can be boosted by scaffold- and seeded scaffold-reconstruction, achieving, respectively, 50% and 70% restoration of presurgical bone density in 120days, compared to 40% restoration seen in spontaneous regeneration. Although optimization of the regenerative performance is needed, these results will help to establish a baseline reference for future experiments.

Epidemiological, anatomopathological and immunohistochemical profiles of male breast cancer in Sidi Bel Abbes, Algeria (Profiles of male breast cancer)

Epidemiological, anatomopathological and immunohistochemical profiles of male breast cancer in Sidi Bel Abbes, Algeria (Profiles of male breast cancer)

Mucinous tubular and spindle renal cell carcinoma revealed by a trauma of the kidney: a case report

BackgroundMucinous tubular and spindle cell carcinoma is a rare renal tumor. It has been recognized as a distinct entity in the 2004 World Health Organization tumor classification. Since then, several dozen of these tumor have been reported with additional complementary morphologic characteristics, immunohistochemical profile, and molecular genetic features that have further clarified its clinicopathologic aspects.Case presentationWe report the case of a 52-year-old male African patient who was found to have a mucinous tubular and spindle renal cell carcinoma on a nephrectomy specimen for a severe kidney trauma.ConclusionsThis tumor has a histological spectrum ranging from low to high grade, which includes sarcomatoid differentiation that can confer the tumor an aggressive clinical course.

Metastatic onset of prostate carcinoma: A clinical and pathological challenge.

Prostate cancer is the second most common cancer, following lung cancer, and the fifth leading cause of cancer death in men worldwide. The onset of the disease, characterized by symptoms or changes caused by distant metastases, is rare and poses a challenge for clinicians and pathologists. We aimed to present a series of prostate carcinoma (PC) with unusual, histologically confirmed distant metastases (pM1) at the time of diagnosis, which raised suspicions of other types or origins of the primary tumor. Patients diagnosed with PC and distant metastases within a five-year timeframe (2017-2022) were extracted from the hospital database. The following data were collected: patient's age, imaging data, serum PSA level, and histopathological evaluation results. Patients with unusual distant metastases were selected and analyzed. We identified 10 patients in whom the diagnosis of PC was established following histopathological examination of tissue taken from distant metastatic sites (pM1). In three patients, the location of distant metastases was unusual: retroperitoneal, cranial/dural/epicranial and supradiaphragmatic lymph nodes which posed diagnostic challenges. Establishing the prostate origin of the tumor relied on immunohistochemical (IHC) investigation guided by clinical-imaging information. A metastasis of PC may rarely present as a cranial/dural tumor, retroperitoneal, or supradiaphragmatic lymphadenopathies in a man over the age of 50, but it should be taken into consideration. In the absence of correlated clinical, imaging, and histopathological/IHC data, diagnosing distant metastasis from PC is difficult, especially considering its potentially confusing IHC profile.

Identification of retinal oligomeric, citrullinated, and other tau isoforms in early and advanced AD and relations to disease status

This study investigates various pathological tau isoforms in the retina of individuals with early and advanced Alzheimer’s disease (AD), exploring their connection with disease status. Retinal cross-sections from predefined superior-temporal and inferior-temporal subregions and corresponding brains from neuropathologically confirmed AD patients with a clinical diagnosis of either mild cognitive impairment (MCI) or dementia (n = 45) were compared with retinas from age- and sex-matched individuals with normal cognition (n = 30) and non-AD dementia (n = 4). Retinal tau isoforms, including tau tangles, paired helical filament of tau (PHF-tau), oligomeric-tau (Oligo-tau), hyperphosphorylated-tau (p-tau), and citrullinated-tau (Cit-tau), were stereologically analyzed by immunohistochemistry and Nanostring GeoMx digital spatial profiling, and correlated with clinical and neuropathological outcomes. Our data indicated significant increases in various AD-related pretangle tau isoforms, especially p-tau (AT8, 2.9-fold, pS396-tau, 2.6-fold), Cit-tau at arginine residue 209 (CitR209-tau; 4.1-fold), and Oligo-tau (T22+, 9.2-fold), as well as pretangle and mature tau tangle forms like MC-1-positive (1.8-fold) and PHF-tau (2.3-fold), in AD compared to control retinas. MCI retinas also exhibited substantial increases in Oligo-tau (5.2-fold), CitR209-tau (3.5-fold), and pS396-tau (2.2-fold). Nanostring GeoMx analysis confirmed elevated retinal p-tau at epitopes: Ser214 (2.3-fold), Ser396 (2.6-fold), Ser404 (2.4-fold), and Thr231 (1.8-fold), particularly in MCI patients. Strong associations were found between retinal tau isoforms versus brain pathology and cognitive status: a) retinal Oligo-tau vs. Braak stage, neurofibrillary tangles (NFTs), and CDR cognitive scores (ρ = 0.63–0.71), b) retinal PHF-tau vs. neuropil threads (NTs) and ABC scores (ρ = 0.69–0.71), and c) retinal pS396-tau vs. NTs, NFTs, and ABC scores (ρ = 0.67–0.74). Notably, retinal Oligo-tau strongly correlated with retinal Aβ42 and arterial Aβ40 forms (r = 0.76–0.86). Overall, this study identifies and quantifies diverse retinal tau isoforms in MCI and AD patients, underscoring their link to brain pathology and cognition. These findings advocate for further exploration of retinal tauopathy biomarkers to facilitate AD detection and monitoring via noninvasive retinal imaging.

Mixed Large Cell Neuroendocrine Carcinoma and Endometrioid Adenocarcinoma: A Rare Case Report with Review of Literature

ABSTRACT We report the case of a 60-year-old female who presented with postmenopausal bleeding after she underwent investigations followed by a total abdominal hysterectomy with bilateral salpingo-oophorectomy and pelvic lymphadenectomy. A diagnosis of low-grade endometrioid adenocarcinoma admixed with large cell neuroendocrine carcinoma (NEC) was made based on the histomorphology and immunohistochemical profile. NEC of the endometrium is a rare and highly aggressive neoplasm requiring a multidisciplinary approach for its treatment. As treatment strategies are changing over time, preoperating imaging evaluation and histopathological examination with molecular characterization whenever possible are essential to follow, to offer the appropriate information to surgeons and/or oncologists for optimal management in these patients.

An immunohistochemical study of diffuse large B-cell lymphoma with molecular subtyping based on Hans algorithm.

Diffuse large B-cell lymphoma (DLBCL) is the most common type of B-cell lymphoma accounting for about 40% of all lymphomas. The international prognostic index (IPI), which relies on clinical and laboratory parameters, is used as a prognostic tool in DLBCL. In this study, we have included cases of DLBCL not otherwise specified (NOS) type to test the usefulness of the biological subclassification of DLBCL by immunohistochemistry (IHC) using the Hans algorithm into the germinal center B-like (GCB) type and nongerminal center (non-GCB) type. We correlated the subtypes with the demographics, site of involvement, IPI scores, and stage. 1. To study the immunohistochemical profile of DLBCL. 2. To classify patients with DLBCL into germinal center and nongerminal center subtypes. 3. To review the clinical presentations, clinical staging, and follow-up data in cases of DLBCL. A total of 152 cases of DLBCL reported from January 2010 to March 2018 were included in this study. Clinical data, treatment details, and follow-up were reviewed. Apart from the routine IHC markers for DLBCL, additional markers CD10, BCL6, and MUM 1 were performed to classify DLBCL into GCB type and non-GCB type using the Hans algorithm. The median age of presentation was 53 years with male-to-female ratio of 2:1. Most of the patients presented with nodal involvement (56.6%); cervical lymph node is the most common site (46.5%). The majority of the patients presented in Ann Arbor stage 1 (44.8%). According to the international prognostic index, 34.8% had a score of 3 (high intermediate). After IHC studies, GCB subtype (51.5%) of DLBCL emerged as more common than non-GCB type (48.5%). The two subtypes differed significantly with regard to sex (i.e. GCB type was more common in males and non-GCB type in females) and showed no significance with regard to any of the other clinical features and prognostic parameters evaluated. Our study showed that IHC was a useful tool to subclassify DLBCL into GCB and non-GCB subtypes and may be easily incorporated in routine clinical practice.

PEComa With MITF Overexpression: Clinicopathologic and Molecular Analysis of a Series of 36 Cases.

Perivascular epithelioid cell neoplasms (PEComas) are tumors of uncertain cell lineage that occur across a wide age range, at a variety of anatomic sites, and with a female predominance. Most PEComas are associated with dysregulation of the mTOR pathway, most commonly through inactivating mutations of TSC2 or TSC1. However, a small subset of PEComas are instead associated with TFE3 gene fusions. MITF is closely related to TFE3 and is frequently overexpressed in PEComas, often in a mutually exclusive manner with TFE3. Here we report the clinical, histopathologic, and molecular features of MITF-overexpressing PEComas in a series of 36 cases. The clinical and morphologic features were comparable to conventional PEComa, although the immunohistochemical profile was notable for the relatively limited expression of melanocytic markers, a surprising finding given that MITF is the master regulator of melanocytic differentiation. At the molecular level, 20 cases (56%) showed supernumerary copies of the MITF gene, suggesting a potential explanation for MITF overexpression. A putative genetic driver event within the mTOR pathway was identified in 11 of 15 cases (73%) analyzed by DNA or RNA sequencing. Interestingly, the malignant PEComas showed 2 distinguishing molecular features: they were associated with a complex chromosomal copy number profile, and they tended to show additional genetic changes, most commonly inactivating events involving TP53, RB1, and ATRX. These results elucidate key features of PEComas showing MITF overexpression, begin to explain the molecular basis for MITF overexpression in some PEComas and identify potential molecular correlates for malignancy that may be applicable to the broader PEComa family.

Diffuse glioneuronal tumor with oligodendroglioma-like features and nuclear clusters (DGONC), new name and new problems: an illustration of one case with atypical morphology and biology

A novel histomolecular tumor of the central nervous system (CNS), the “diffuse glioneuronal tumor with oligodendroglioma-like features and nuclear clusters (DGONC),” has recently been identified, based on a distinct DNA methylation profile and has been added to the 2021 World Health Organization Classification of CNS Tumors. This glioneuronal tumor mainly affects the supratentorial area in children and recurrently presents with a monosomy of chromosome 14. Herein, we report the case of a DNA-methylation based diagnosis of DGONC having atypical features, such as pseudo-rosettes and the absence of a chromosome 14 monosomy, thus rendering its diagnosis very challenging. Because of the wide variety of morphologies harbored by DGONC, a large range of differential diagnoses may be hypothesized from benign to malignant. Interestingly, the current case, like one previously reported, exhibited a co-expression of OLIG2, synaptophysin and SOX10, without GFAP immunopositivity. This particular immunophenotype seems to be a good indicator for a DGONC diagnosis. The classification of DGONC amongst glioneuronal or embryonal tumors is still debated. The clinical (a pediatric supratentorial tumor), morphological (from a benign oligodendroglioma-like tumor with microcalcifications and possible neuropil-like islands to a malignant embryonal tumor with a possible spongioblastic pattern), and immunohistochemical (co-expression of OLIG2 and synaptophsyin) profiles resemble CNS, neuroblastoma, FOXR2-activated and may potentially bring them together in a future classification. Further comprehensive studies are needed to conclude the cellular origin of DGONC and its prognosis.

Endometrioid ovarian carcinoma landscape: pathological and molecular characterization.

Endometrioid ovarian cancers (EOvC) are usually managed as serous tumors. In this study, we conducted a comprehensive molecular investigation to uncover the distinct biological characteristics of EOvC. This retrospective multicenter study involved patients from three European centers. We collected clinical data and formalin-fixed paraffin-embedded (FFPE) samples for analysis at the DNA level using panel-based next-generation sequencing and array-comparative genomic hybridization. Additionally, we examined mRNA expression using NanoString nCounter® and protein expression through tissue microarray. We compared EOvC with other ovarian subtypes and uterine endometrioid tumors. Furthermore, we assessed the impact of molecular alterations on patient outcomes, including progression-free survival (PFS) and overall survival (OS). Preliminary analysis of clinical data from 668 patients, including 86 (12.9%) EOvC, revealed more favorable prognosis for EOvC compared with serous ovarian carcinoma (5-year OS of 60% versus 45%; P = 0.001) driven by diagnosis at an earlier stage. Immunohistochemistry and copy number alteration (CNA) profiles of 43 cases with clinical data and FFPE samples available indicated that EOvC protein expression and CNA profiles were more similar to endometrioid endometrial tumors than to serous ovarian carcinomas. EOvC exhibited specific alterations, such as lower rates of PTEN loss, mutations in DNA repair genes, and P53 abnormalities. Survival analysis showed that patients with tumors harboring loss of PTEN expression had worse outcomes (median PFS 19.6 months vs. not reached; P = 0.034). Gene expression profile analysis confirmed that EOvC differed from serous tumors. However, comparison to other rare subtypes of ovarian cancer suggested that the EOvC transcriptomic profile was close to that of ovarian clear cell carcinoma. Downregulation of genes involved in the PI3K pathway and DNA methylation was observed in EOvC. In conclusion, EOvC represents a distinct biological entity and should be regarded as such in the development of specific clinical approaches.

Comparative Analysis of Nanos and Ago Genes Expression in the Germinative Cells Isolated from Germinal Layer and the Neck Region of Echinococcus granulosus.

We aimed to evaluate the differential expression of nanos and ago genes in the protoscoleces, germinal layer, the neck, and the sucker regions of adult Echinococcus granulosus. The study was conducted in 2018 at the Research Center for Hydatid Disease in Iran, Kerman University of Medical Sciences, Kerman, Iran. In the present study E. granulosus protoscoleces were cultured in a di-phasic medium to obtain strobilated worms. The strobilated worms were harvested and using a sterile razor blade, the neck region was separated. In the molecular study the neck sections were compared with the tissues derived from the suckers from the same worm. The primers were specifically designed for RT-qPCR on nanos and ago. The germinative cells were isolated from the cyst germinal layer and cultured in DMEM for further molecular studies. The Immunohisto-chemical profile was designed to explore the nature of nanos protein in the strobilated worms. Differences between and within groups were statistically assessed relative to the protoscoleces. An increasing nanos gene expressions were found in sucker, neck, cells and germinal layer in comparison to the protoscoleces. The expression of ago gene was decreased in sucker, cell and germinal layer, and increased in the neck region in comparison to the protoscoleces. The results showed that both genes were expressed in all developmental stages of E. granulosus. nanos and ago genes were differentially expressed at different developmental stages of E. granulosus and may contribute to differentiation of the parasite.

Abstract PO-033: Unveiling the complexity of HIV-associated plasmablastic lymphoma: A case report of anal cavity presentation with unconventional immunohistochemical profile

Abstract Introduction: HIV-associated Plasmablastic Lymphoma (PBL) stands as a rare subset of Diffuse Large B-cell Lymphoma (DLBCL), marked as an AIDS-defining malignancy. The primary presentation site is the oral cavity. Although extra-oral PBLs have been reported, these are considered to be very rare. Despite its scarcity, understanding its pathogenesis, diagnosis, and management remains paramount. Herein, we elucidate a distinctive case of HIV-associated PBL manifesting in the anal cavity, an infrequent site, accompanied by an intriguing immunohistochemical signature. Clinical Course: A 30-year-old male presented with symptoms indicative of an anal mass, ultimately diagnosed as Plasmablastic Lymphoma. Further evaluation disclosed a pulmonary nodule and a substantial anal-perineum mass. Given the concurrent HIV infection, initiation of retroviral therapy was crucial alongside lymphoma-directed treatment. Notably, immunohistochemical analysis revealed an unusual profile, encompassing positive expression for CD45, CD38, MYC, OCT2, and MUM1, alongside a heightened Ki-67 proliferation index. Conversely, markers such as CD20, PAX5, Pankeratin, CK7, CK20, MART1, CD30, HHV8 CD138 and P63 exhibited negativity. Epstein-Barr virus (EBV) presence was detected. Treatment initiation comprised HyperCVAD chemotherapy, supplemented by intrathecal chemotherapy and methotrexate. Discussion: Immunophenotypically, PBL conventionally lacks CD45, CD20, and CD79a expression while expressing CD38, CD138, and MUM1. However, our case deviated with positive CD45 expression and negative CD138. Treatment paradigms for HIV-associated PBL encompass intensive regimens such as CHOP-alike regimens with other intensive alternatives such as CODOX-M/IVAC, DA-EPOCH or Hyper-CVAD therapy, with limited intrathecal agent utilization to avert central nervous system involvement. Despite aggressive therapeutic measures, prognosis remains guarded. The progression free survival rates range between 6 and 7 months, with median overall survival falling within the 11 to 13 month range. Long-term survivors predominantly emerge among pediatric patients, underscoring potential disparities in disease biology and treatment response. Conclusion: This case epitomizes the heterogeneity and intricacy inherent in HIV-associated Plasmablastic Lymphoma. The unconventional presentation in the anal cavity, coupled with an atypical immunohistochemical profile, poses challenges to diagnostic and therapeutic strategies. Collaborative efforts with specialized centers are imperative for optimal disease management, accentuating the imperative for sustained research endeavors to enhance outcomes in this aggressive lymphoma variant. Citation Format: Aliya M Khan, Mehmet Hepgur, Sophia Navajas. Unveiling the complexity of HIV-associated plasmablastic lymphoma: A case report of anal cavity presentation with unconventional immunohistochemical profile [abstract]. In: Proceedings of the Fourth AACR International Meeting on Advances in Malignant Lymphoma: Maximizing the Basic-Translational Interface for Clinical Application; 2024 Jun 19-22; Philadelphia, PA. Philadelphia (PA): AACR; Blood Cancer Discov 2024;5(3_Suppl):Abstract nr PO-033.

Histopathological Spectrum and Immunohistochemistry Profile of Rare Breast Cancers - A Quick Review

Histopathological Spectrum and Immunohistochemistry Profile of Rare Breast Cancers - A Quick Review

Ancillary immunohistochemical and molecular testing in the classification of cutaneous sweat gland/duct neoplasms: A validation study with emphasis on histomorphologic correlation and pathological diagnosis

Sweat gland neoplasms represent a challenging area of dermatopathology, as they are relatively uncommon and often histopathologically complex. Recent studies have uncovered distinct immunohistochemical and molecular profiles in several sweat gland neoplasms, including digital papillary adenocarcinoma (DPA), papillary eccrine adenoma/tubular apocrine adenoma (PEA/TAA), poroid family tumors (PFT)/porocarcinoma, and clear cell hidradenoma (CCH)/clear cell hidradenocarcinoma (CCHCa). To further evaluate the diagnostic utility of ancillary studies in various sweat gland neoplasms, we performed an independent validation study in a cohort of patients with acral and non-acral tumors (9 DPA, 8 PEA/TAA, 13 PFT, 5 porocarcinoma, 23 CCH, 7 CCHCa, 6 sweat gland carcinoma not otherwise specified). p63 immunohistochemistry (IHC) demonstrated a myoepithelial pattern in 8/8 DPA and 4 of 4 tested PEA/TAA cases, and showed a ductal pattern in all tested PFT/porocarcinoma and CCH/CCHCa cases (42/42). All PEA/TAA (8/8) cases were positive for BRAF V600E IHC. 5 of 12 tested PFT and 5/5 porocarcinoma cases showed either positive staining with NUT IHC or harbored YAP1::NUTM1 fusion gene by RNA sequencing. MAML2 fluorescence in situ hybridization (FISH) was positive in all CCH and CCHCa cases (23/23 and 7/7, respectively). Our results further support the usefulness of appropriate ancillary studies in precise classification of sweat gland tumors, which may be routinely applied in diagnostic pathology practice when morphologic evaluation is in doubt.

Inflammatory rhabdomyoblastic tumor, pheochromocytoma, and pulmonary hamartoma in a patient with neurofibromatosis type 1: a case report

BackgroundInflammatory rhabdomyoblastic tumors are relatively recently recognized soft tissue tumors with a low malignant potential. Here, we present a case of concurrent inflammatory rhabdomyoblastic tumor (IRMT), adrenal pheochromocytoma, and pulmonary hamartoma in a patient with neurofibromatosis type 1 (NF1). To our knowledge, this is the first time that this constellation of tumors has been described in the literature.Case presentationA female patient in her late 20s with known NF1 was diagnosed with an inflammatory rhabdomyoblastic tumor, pheochromocytoma, and pulmonary hamartoma in a short succession. IRMT was found to harbor a near-haploid genome and displayed a typical immunohistochemical profile as well as a focal aberrant p53 expression pattern.ConclusionsThis case report strengthens the theory that defects in the tumor suppressor NF1 play a central role in the pathogenesis of inflammatory rhabdomyoblastic tumors and that IRMT may be part of the spectrum of neurofibromatosis type 1 related tumors.

Immunohistochemical Profiling of SSTR2 and HIF-2α with the Tumor Microenvironment in Pheochromocytoma and Paraganglioma.

Metastatic pheochromocytomas and paragangliomas (PPGLs) are rare endocrine malignancies with limited effective treatment options. The association between the tumor microenvironment (TME) with somatostatin receptor 2 (SSTR2) and hypoxia-induced factor-2α (HIF-2α) in PPGLs, critical for optimizing combination therapeutic strategies with immunotherapy, remains largely unexplored. To evaluate the association of SSTR2 and HIF-2α immunoreactivity with the TME in patients with PPGLs, we analyzed the expression of SSTR2A, HIF-2α, and TME components, including tumor-infiltrating lymphocytes (CD4 and CD8), tumor-associated macrophages (CD68 and CD163), and PD-L1, using immunohistochemistry in patients with PPGLs. The primary outcome was to determine the association of the immune profiles with SSTR2A and HIF-2α expression. Among 45 patients with PPGLs, SSTR2A and HIF2α were positively expressed in 21 (46.7%) and 14 (31.1%) patients, respectively. The median PD-L1 immunohistochemical score (IHS) was 2.0 (interquartile range: 0-30.0). Positive correlations were observed between CD4, CD8, CD68, and CD163 levels. A negative correlation was found between the CD163/CD68 ratio (an indicator of M2 polarization) and SSTR2A expression (r = -0.385, p = 0.006). HIF-2α expression showed a positive correlation with PD-L1 IHS (r = 0.348, p = 0.013). The co-expression of PD-L1 (HIS > 10) and HIF-2α was found in seven patients (15.6%). No associations were observed between SDHB staining results and the CD163/CD68 ratio, PD-L1, or SSTR2A expression. Our data suggest the potential of combination therapy with immunotherapy and peptide receptor radionuclide therapy or HIF-2α inhibitors as a treatment option in selected PPGL populations.

Biomarker conversion from primary breast cancer to synchronous axillary lymph node metastasis and neoadjuvant therapy response: a single-center analysis

PurposeThe biomarker characteristics of breast cancer plays an important role in predicting treatment sensitivity. The aim of the present study was to compare immunohistochemical profiles (ER, PR, HER2, and Ki67) between the primary tumor and synchronous axillary lymph node metastasis and investigate the subsequent effects on neoadjuvant therapy response.MethodsA total of 358 patients with pathologically confirmed synchronous axillary lymph node metastasis at first diagnosis and treated by neoadjuvant therapy at Peking University First Hospital from January 1, 2013 to December 31, 2022 were included in this retrospective study. Clinicopathologic data, especially receptor status in primary and metastatic foci, was collected for each case.ResultsChange of ER, PR, HER2, and Ki67 expression was observed in 5.9%, 8.7%, 12.6%, and 17.3% of patients, respectively. HR discordance was observed more frequently when the ER status (p = 0.023) or PR status (p = 0.010) of primary tumor was negative, while HER2 discordance seemed to be more frequent when the HER2 status of primary tumor was HER2-0 or HER2-low (p < 0.001). Patients with loss of HR-positivity (positive to negative) responded to neoadjuvant chemotherapy better compared to those with stable positive HR expression (50% vs. 11.1%, p = 0.0017). A significantly decrease in pCR rate was observed in patients with unstable HER2 status, but not in the HER2-0/HER2-low subgroup.ConclusionReceptor discordance between primary tumor and synchronous axillary LNM appears to already exist before any anti-tumor therapy. This instability has limited clinical impact on the choice of neoadjuvant therapy at current stage, but further investigation is warranted with the incremental application of endocrine drugs and ADCs in neoadjuvant therapy.