Identification of Irpex and Rhodotorula on surveillance bronchoscopy in a pediatric lung transplant recipient: A case report and review of literature of these atypical fungal organisms.

BACKGROUND: Invasive fungal disease (IFD) is a frequent complication in pediatric lung transplant recipients, occurring in up to 12% of patients in the first year. Risk factors for infection include impaired lung defenses and intense immunosuppressive regimens. While most IFD occurs from Aspergillus, other fungal conidia are continuously inhaled, and infections with fungi on a spectrum of human pathogenicity can occur. CASE REPORT: We report a case of a 17-year-old lung transplant recipient in whom Irpex lacteus and Rhodotorula species were identified during surveillance bronchoscopy. She was asymptomatic and deemed to be colonized by Irpex lacteus and Rhodotorula species following transplant. 2 years after transplantation, she developed a fever, respiratory symptoms, abnormal lung imaging, and histological evidence of acute and chronic bronchitis on transbronchial biopsy. After developing symptoms concerning for a pulmonary infection and graft dysfunction, she was treated for a presumed IFD. Unfortunately, further diagnostic testing could not be performed at this time given her tenuous clinical status. Despite the initiation of antifungal therapy, her graft function continued to decline resulting in a second lung transplantation. CONCLUSIONS: This case raises the concern for IFD in lung transplant recipients from Irpex species. Further investigation is needed to understand the pathogenicity of this organism, reduce the incidence and mortality of IFD in lung transplant recipients, and refine the approach to diagnosis and manage the colonization and isolation of rare, atypical fungal pathogens in immunocompromised hosts.

Large Malignant Testicular/Paratesticular Tumors in Adolescence: Assessment of Gross Tumor Size in a Vulnerable Age Group.

OBJECTIVE: We hypothesized that reticence to address a groin mass may result in late presentation of testicular/paratesticular malignancy in early puberty through adolescence. METHODS: Malignant testicular and paratesticular tumors (malignant germ cell tumors and rhabdomyosarcomas) diagnosed at our institution from 1994-2023 for patients aged 11-20 were included. Clinicopathologic features were recorded, and statistically analyzed. RESULTS: Eighty-five cases were identified. Patient ages ranged from 11 to 20 years (mean 17 years, median 16 years). The greatest tumor dimension ranged from 0.8 to 18.0 cm (mean 4.4 cm, median 3.5 cm). Ten tumors (11.8% of cases) were ≥10.0 cm. In the 11-13-year-old age group, 100% of tumors (3/3) were ≥10 cm. The proportion of tumors ≥10 cm was significantly higher in the 11-13-year-old age group than in either the 14-16-year-old (P<0.001) or 17-20-year-old (P<0.001) age groups. CONCLUSION: This adolescent cohort with malignant testicular and paratesticular tumors showed a high proportion (11.8%) of very large (≥10 cm) tumors. Although the reasons are unknown and likely multifactorial, this study suggests that adolescents, particularly the 11-13 year age group, are a vulnerable population.

De novo mutations mediate phenotypic switching in an opportunistic human lung pathogen.

Bacteria evolving within human hosts encounter selective tradeoffs that render mutations adaptive in one context and deleterious in another. Here, we report that the cystic fibrosis-associated pathogen Burkholderia dolosa overcomes in-human selective tradeoffs by acquiring successive point mutations that alternate phenotypes. We sequenced the whole genomes of 931 respiratory isolates from two recently infected patients and an epidemiologically-linked, chronically-infected patient. These isolates are contextualized using 112 historical genomes from the same outbreak strain. Within both newly infected patients, diverse parallel mutations that disrupt O-antigen expression quickly arose, comprising 29% and 63% of their B. dolosa communities by 3 years. The selection for loss of O-antigen starkly contrasts with our previous observation of parallel O-antigen-restoring mutations after many years of chronic infection in the historical outbreak. Experimental characterization revealed that O-antigen loss increases uptake in immune cells while decreasing competitiveness in the mouse lung. We propose that the balance of these pressures, and thus whether O-antigen expression is advantageous, depends on tissue localization and infection duration. These results suggest that mutation-driven alternation during infection may be more frequent than appreciated and is underestimated without dense temporal sampling.

Epstein-Barr virus-positive mucocutaneous ulcer in a patient with ulcerative colitis: a recently described entity to take into account.

Epstein-Barr virus-positive mucocutaneous ulcer (EBVMCU) is a new entity recently included in the classification of B-cell lymphoproliferative disorders associated with Epstein-Barr virus (EBV). It is related to immunosuppression and it usually appears in the oropharynx or the skin, being the colon an uncommon location. We present the case of a 31-year-old man with ulcerative proctitis being treated with azathioprine (AZA) and adalimumab (ADA), who was admitted to the hospital due to suspicion of a moderate-severe flare of ulcerative proctitis. Microbiological stool analyses were negative, with a positive fecal calprotectin test (2700 mg/kg). Rectoscopy showed severe endoscopic activity, taking multiple biopsies. Intravenous steroids were started at a dose of 60 mg/day. He presented a favorable clinical and analytical evolution, being discharged from the hospital. The histological results were received at gastroenterology consultation, being compatible with EBVMCU. AZA and ADA were withdrawn, whereas descending steroid regimen and oral and topical mesalazine were continued, being the clinical response adequate.

Hepatosplenic schistosomiasis: an uncommon cause of liver disease in developed countries.

Schistosomiasis is a parasitic infection caused by trematode species of the genus Schistosoma. It is prevalent in tropical regions of Africa, Asia and South America, being rare in Europe, where it is usually diagnosed in immigrants and tourists from endemic areas. It has different clinical forms of presentation. Hepatosplenic schistosomiasis produces periportal fibrosis, which can progress to presinusoidal portal hypertension, with all its associated complications. We present the case of a 43-year-old female patient from the Philippines who was referred to gastroenterology consultation due to liver enzyme alteration with a predominantly cholestatic pattern. An aetiological study was performed, with negative results. An abdominal ultrasound revealed signs of chronic liver disease, with transient elastography of 9.5 kPa. A percutaneous liver biopsy was performed, with histological findings consistent with infestation by schistosome eggs, receiving treatment with praziquantel and subsequently verifying its eradication with a stool test.

Lack of apoptosis leads to cellular senescence and tumorigenesis in Drosophila epithelial cells.

Programmed cell death (apoptosis) is a homeostasis program of animal tissues designed to remove cells that are unwanted or are damaged by physiological insults. To assess the functional role of apoptosis, we have studied the consequences of subjecting Drosophila epithelial cells defective in apoptosis to stress or genetic perturbations that normally cause massive cell death. We find that many of those cells acquire persistent activity of the JNK pathway, which drives them into senescent status, characterized by arrest of cell division, cell hypertrophy, Senescent Associated ß-gal activity (SA-ß-gal), reactive oxygen species (ROS) production, Senescent Associated Secretory Phenotype (SASP) and migratory behaviour. We have identified two classes of senescent cells in the wing disc: 1) those that localize to the appendage part of the disc, express the upd, wg and dpp signalling genes and generate tumour overgrowths, and 2) those located in the thoracic region do not express wg and dpp nor they induce tumour overgrowths. Whether to become tumorigenic or non-tumorigenic depends on the original identity of the cell prior to the transformation. We also find that the p53 gene contributes to senescence by enhancing the activity of JNK.

An intronic variant in TBX4 in a single family with variable and severe pulmonary manifestations.

A male infant presented at term with neonatal respiratory failure and pulmonary hypertension. His respiratory symptoms improved initially, but he exhibited a biphasic clinical course, re-presenting at 15 months of age with tachypnea, interstitial lung disease, and progressive pulmonary hypertension. We identified an intronic TBX4 gene variant in close proximity to the canonical donor splice site of exon 3 (hg 19; chr17:59543302; c.401 + 3 A > T), also carried by his father who had a typical TBX4-associated skeletal phenotype and mild pulmonary hypertension, and by his deceased sister who died shortly after birth of acinar dysplasia. Analysis of patient-derived cells demonstrated a significant reduction in TBX4 expression resulting from this intronic variant. Our study illustrates the variable expressivity in cardiopulmonary phenotype conferred by TBX4 mutation and the utility of genetic diagnostics in enabling accurate identification and classification of more subtly affected family members.

Large cell calcifying Sertoli cell tumour: molecular and immunohistochemical assessment of a series comprising non-metastasising and metastasising neoplasms.

Large cell calcifying Sertoli cell tumour (LCCSCT) is a type of testicular sex cord-stromal tumour that may occur sporadically or in the context of Carney complex and other genetic syndromes. A subset is clinically malignant, and the molecular mechanisms that drive such aggressive behaviour remain unknown. METHODS AND RESULTS: We analysed 21 samples from 20 patients with LCCSCT (12 non-metastasising and eight metastasising) using PRKAR1A immunohistochemistry (IHC) and next-generation sequencing. All tumours except two (cases 17 and 20, both metastasising) demonstrated loss of PRKAR1A expression. Among 11 cases with interpretable sequencing results, all harboured pathogenic single nucleotide variants of PRKAR1A. Evidence of loss of heterozygosity (LOH) of PRKAR1A was present in all tumours with interpretable zygosity data, but the mechanisms of LOH were different for non-metastasising and metastasising tumours. Non-metastasising tumours demonstrated only copy-neutral LOH, while metastasising tumours demonstrated a spectrum of mechanisms of LOH, including copy-loss LOH, two concurrent mutations or copy-neutral LOH. Relevant molecular findings in non-metastasising LCCSCT were limited to PRKAR1A variants. In contrast, all metastasising LCCSCTs with interpretable data harboured additional pathogenic variants, including (but not restricted to) BRCA2 mutations with evidence of LOH and bi-allelic CDKN2A/B deletions. Three patients harboured PRKAR1A variants of inferred germline origin, including one with Carney complex and two without known syndromic features. CONCLUSIONS: This study further confirms that PRKAR1A IHC is a useful diagnostic tool for both non-metastasising and metastasising tumours and suggests that molecular analyses can be helpful to identify non-metastasising tumours with malignant potential in selected patients. Importantly, these results highlight that germline assessment could be beneficial for all patients presenting with LCCSCT.

Testicular Juvenile Granulosa Cell Tumors Demonstrate Recurrent Loss of Chromosome 10 and Absence of Molecular Alterations Described in Ovarian Counterparts.

Testicular juvenile granulosa cell tumors (JGCTs) are a rare type of sex cord-stromal tumor, accounting for <5% of all neoplasms of the prepubertal testis. Previous reports have demonstrated sex chromosome anomalies in a small subset of cases, but the molecular alterations associated with JGCTs remain largely undescribed. We evaluated 18 JGCTs using massive parallel DNA and RNA sequencing panels. The median patient age was <1 month (range, newborn to 5 months). The patients presented with scrotal or intra-abdominal masses/enlargement, and all underwent radical orchiectomy (17 unilateral and 1 bilateral). The median tumor size was 1.8 cm (range, 1.3-10.5 cm). Histologically, the tumors were purely cystic/follicular or mixed (ie, solid and cystic/follicular). All cases were predominantly epithelioid, with 2 exhibiting prominent spindle cell components. Nuclear atypia was mild or absent, and the median number of mitoses was 0.4/mm2 (range, 0-10/mm2). Tumors frequently expressed SF-1 (11/12 cases, 92%), inhibin (6/7 cases, 86%), calretinin (3/4 cases, 75%), and keratins (2/4 cases, 50%). Single-nucleotide variant analysis demonstrated the absence of recurrent mutations. RNA sequencing did not detect gene fusions in 3 cases that were sequenced successfully. Recurrent monosomy 10 was identified in 8 of 14 cases (57%) with interpretable copy number variant data, and multiple whole-chromosome gains were present in the 2 cases with significant spindle cell components. This study demonstrated that testicular JGCTs harbor recurrent loss of chromosome 10 and lack the GNAS and AKT1 variants described in their ovarian counterparts.

Mpox (Monkeypox) Presenting as Cervical and Vulvar Disease.

BACKGROUND: Since the beginning of the current mpox (formerly "monkeypox") outbreak in May 2022, 23,465 confirmed cases of monkeypox virus infection have been reported in Europe; women represent less than 1% of these cases. Mpox lesions are found with greater frequency in the genital area, and, in women, have been described primarily in the vulva. CASE: We present a case of monkeypox virus infection in a 28-year-old woman confirmed by polymerase chain reaction testing, in which the only clinical manifestation was the appearance of concomitant lesions in the cervix and the vulva, with no other clinical features. No other sexual transmitted diseases were found. The lesions disappeared spontaneously in 2 weeks. CONCLUSION: Mpox lesions can affect the cervix; thus, recognition by gynecologists is important. Given the current epidemic outbreak, correct identification is essential to help control disease transmission.

Advances in Imaging of the ChILD - Childhood Interstitial Lung Disease.

Childhood interstitial lung disease (chILD) refers to a diverse group of rare diffuse parenchymal lung diseases affecting infants and children, previously associated with considerable diagnostic confusion due to a lack of information regarding their clinical, imaging, and histopathologic features. Due to improved lung biopsy techniques, established pathologic diagnostic criteria, and a new structured classification system, there has been substantial improvement in the understanding of chILD over the past several years. The main purpose of this article is to review the latest advances in the imaging evaluation of pediatric interstitial lung disease within the framework of the new classification system.

Distribución espacial de la morbimortalidad atribuible a la contaminación del aire por PM2.5 en Medellín (Colombia), 2010-2016

Objetivo: Esta investigación buscó establecer la distribución espacial de la morbimortalidad atribuible a la contaminación del aire ambiental por materia particulada (particulate matter 2.5) (PM2.5) en Medellín entre 2010 y 2016. Metodología: Se planteó un estudio ecológico. Se estandarizaron las direcciones de residencia de los pacientes atendidos y las defunciones por eventos de interés. Se emplearon mapas de calor, mediante el análisis de densidad de Kernel, por núcleos domiciliarios para áreas de 10 000 m2. Resultados: Se encontraron 45 487 y 2743 casos y defunciones, respectivamente, atribuibles a la contaminación del aire ambiental por PM2.5 con datos de localización geográfica. La zona suroccidental de la ciudad presentó las mayores densidades de eventos atribuibles por todas las causas estudiadas y por grupo de eventos, con algunas áreas pequeñas en otros lugares. Por su parte, la zona suroriental, con las mejores condiciones socioeconómicas, manifestó la menor concentración de eventos atribuibles. Conclusión: La información geocodificada de la morbimortalidad por núcleos domiciliarios posibilitó establecer la distribución de casos y muertes atribuibles a la contaminación ambiental del aire por PM2.5 en Medellín, con mayor concentración al suroccidente de la ciudad, lo que permite evidenciar la presencia de disparidades territoriales de este fenómeno.

Objective: This research aimed to establish the spatial distribution of morbidity and mortality attributable to particulate matter (pm2.5) air pollution in Medellín between 2010 and 2016. Methodology: An ecological study was proposed. Addresses of patients treated and deceased due to events of interest were standardized. Heat maps were used, through Kernel density analysis per residential units for areas of 10,000 m2. Results: 45,487 cases and 2,743 deaths attributable to pm2.5 air pollution with geographic location data were found. The southwestern area of the city presented the highest event densities attributable to all causes studied and by group of events, with some small areas in other places. On the other hand, the southeastern area, with the best socio-economic conditions, showed the lowest concentration of attributable events. Conclusion: Geocoded information of morbidity and mortality by residential units made it possible to establish the distribution of cases and deaths attributable to pm2.5 air pollution in Medellín, with a greater concentration in the southwestern part of the city, which makes the presence of territorial disparities in this phenomenon observable.

Objetivo: Esta pesquisa procurou estabelecer a distribuição espacial da morbimortalidade atribuível à poluição do ar ambiental por matéria particulada (particulate matter 2.5) (PM2.5) em Medellín entre 2010 e 2016. Metodologia: Propôs-se uma abordagem ecológica. Padronizaram-se os endereços de residência dos pacientes atendidos e as mortes por eventos de interesse. Empregaram-se mapas de calor, por meio da análise de densidade de Kernel, por núcleos domiciliários para áreas de 10000 m2. Resultados: Acharam-se 45487 e 2743 casos e mortes, respectivamente, atribuíveis à poluição do ar ambiental por PM2.5 com dados de localização geográfica. A zona do sudoeste da cidade apresentou as maiores densidades de eventos atribuíveis por todas as causas estudadas e por grupo de eventos, com algumas áreas pequenas em outros lugares. Por sua parte, a zona do sudeste, com as melhores condições socioeconômicas, manifestou a menor concentração de eventos atribuíveis. Conclusão: A informação geocodificada da morbimortalidade por núcleos domiciliários possibilitou estabelecer a distribuição de casos e mortes atribuíveis à poluição ambiental do ar por PM2.5 em Medellín, com maior concentração no sudoeste da cidade, o que permite evidenciar a presença de disparidades territoriais deste fenômeno

Lung and Pleural Findings of Children with Pulmonary Vein Stenosis with and without Aspiration: MDCT Evaluation.

Purpose: To retrospectively compare the lung and pleural findings in children with pulmonary vein stenosis (PVS) with and without aspiration on multidetector computed tomography (MDCT). Materials and Methods: All consecutive children (≤18 years old) with PVS who underwent thoracic MDCT studies from August 2004 to December 2021 were categorized into two groups: children with PVS with aspiration (Group 1) and children with PVS without aspiration (Group 2). Two independent pediatric radiologists retrospectively evaluated thoracic MDCT studies for the presence of lung and pleural abnormalities as follows: (1) in the lung (ground-glass opacity (GGO), consolidation, nodule, mass, cyst(s), interlobular septal thickening, and fibrosis) and (2) in the pleura (thickening, effusion, and pneumothorax). Interobserver agreement between the two reviewers was evaluated by the proportion of agreement and the Kappa statistic. Results: The final study population consisted of 64 pediatric patients (36 males (56.3%) and 43 females (43.7%); mean age, 1.7 years; range, 1 day−17 years). Among these 64 patients, 19 patients (29.7%) comprised Group 1 and the remaining 45 patients (70.3%) comprised Group 2. In Group 1 (children with PVS with aspiration), the detected lung and pleural MDCT abnormalities were: GGO (17/19; 89.5%), pleural thickening (17/19; 89.5%), consolidation (16/19; 84.5%), and septal thickening (16/19; 84.5%). The lung and pleural MDCT abnormalities observed in Group 2 (children with PVS without aspiration) were: GGO (37/45; 82.2%), pleural thickening (37/45; 82.2%), septal thickening (36/45; 80%), consolidation (3/45; 6.7%), pleural effusion (1/45; 2.2%), pneumothorax (1/45; 2.2%), and cyst(s) (1/45; 2.2%). Consolidation was significantly more common in pediatric patients with both PVS and aspiration (Group 1) (p < 0.001). There was high interobserver agreement between the two independent reviewers for detecting lung and pleural abnormalities on thoracic MDCT studies (Kappa = 0.98; CI = 0.958, 0.992). Conclusion: Aspiration is common in pediatric patients with PVS who undergo MDCT and was present in nearly 30% of all children with PVS during our study period. Consolidation is not a typical radiologic finding of PVS in children without clinical evidence of aspiration. When consolidation is present on thoracic MDCT studies in pediatric patients with PVS, the additional diagnosis of concomitant aspiration should be considered.

Pleuropulmonary MDCT Findings: Comparison between Children with Pulmonary Vein Stenosis and Prematurity-Related Lung Disease.

Purpose: To retrospectively compare the pleuropulmonary MDCT findings in children with pulmonary vein stenosis (PVS) and prematurity-related lung disease (PLD). Materials and Methods: All consecutive infants and young children (≤18 years old) who underwent thoracic MDCT studies from July 2004 to November 2021 were categorized into two groups­children with PVS (Group 1) and children with PLD without PVS (Group 2). Two pediatric radiologists independently evaluated thoracic MDCT studies for the presence of pleuropulmonary abnormalities as follows­(1) in the lung (ground-glass opacity (GGO), triangular/linear plaque-like opacity (TLO), consolidation, nodule, mass, cyst(s), interlobular septal thickening, and fibrosis); (2) in the airway (bronchial wall thickening and bronchiectasis); and (3) in the pleura (thickening, effusion, and pneumothorax). Interobserver agreement between the two reviewers was evaluated with the Kappa statistic. Results: There were a total of 103 pediatric patients (60 males (58.3%) and 43 females (41.7%); mean age, 1.7 years; range, 2 days−7 years). Among these 103 patients, 49 patients (47.6%) comprised Group 1 and the remaining 54 patients (52.4%) comprised Group 2. In Group 1, the observed pleuropulmonary MDCT abnormalities were­pleural thickening (44/49; 90%), GGO (39/49; 80%), septal thickening (39/49; 80%), consolidation (4/49; 8%), and pleural effusion (1/49; 2%). The pleuropulmonary MDCT abnormalities seen in Group 2 were­GGO (45/54; 83%), TLO (43/54; 80%), bronchial wall thickening (33/54; 61%), bronchiectasis (30/54; 56%), cyst(s) (5/54; 9%), pleural thickening (2/54; 4%), and pleural effusion (2/54; 4%). Septal thickening and pleural thickening were significantly more common in pediatric patients with PVS (Group 1) (p < 0.001). TLO, bronchial wall thickening, and bronchiectasis were significantly more frequent in pediatric patients with PLD without PVS (Group 2) (p < 0.001). There was high interobserver kappa agreement between the two independent reviewers for detecting pleuropulmonary abnormalities on thoracic MDCT angiography studies (k = 0.99). Conclusion: Pleuropulmonary abnormalities seen on thoracic MDCT can be helpful for distinguishing PVS from PLD in children. Specifically, the presence of septal thickening and pleural thickening raises the possibility of PVS, whereas the presence of TLO, bronchial wall thickening and bronchiectasis suggests PLD in the pediatric population.

Prostatic metaplasia of the vagina in transmasculine individuals.

PURPOSE: To determine the prevalence of prostatic metaplasia in an expanded cohort of transmasculine individuals undergoing gender-affirming resection of vaginal tissue. METHODS: Institutional Review Board approval was obtained. Clinical records were reviewed for all transmasculine individuals undergoing vaginal tissue resection at our institution between January 2018 and July 2021. Corresponding pathology specimens were examined grossly and microscopically, including immunohistochemical stains for NKX3.1, prostate-specific antigen (PSA), and androgen receptor (AR). Vaginal specimens from three patients without androgen supplementation were used as controls. RESULTS: Twenty-one patients met inclusion criteria. The median age at surgery was 26.4 years (range 20.6-34.5 years). All patients had been assigned female gender at birth and lacked endocrine or genetic abnormalities. All were on testosterone therapy; median duration of therapy at surgery was 4.4 years (range 1.4-12.1 years). In the transmasculine group, no gross lesions were identified. Microscopically, all specimens demonstrated patchy intraepithelial glandular proliferation along the basement membrane and/or nodular proliferation of prostate-type tissue within the subepithelial stroma. On immunohistochemical staining, performed for a subset of cases, the glandular proliferation was positive for NKX3.1 (16/16 cases; 100%), PSA (12/14 cases; 85.7%), and AR (8/8 cases; 100%). Controls showed no evidence of prostatic metaplasia. CONCLUSION: One hundred percent of vaginal specimens obtained from transmasculine individuals on testosterone therapy (21/21 cases) demonstrated prostatic metaplasia. Further investigation is warranted to characterize the natural history and clinical significance of these changes. Patients seeking hormone therapy and/or gender-affirming surgery should be counseled on the findings and their yet-undetermined significance.

Randomized Controlled Trial Comparing Nylon and Chromic Gut Sutures After Minor Hand Surgery.

PURPOSE: We sought to compare overall satisfaction with treatment and satisfaction with initial wound healing after closure of office hand and upper extremity surgery wounds using polyamide compared to Chromic gut sutures. METHODS: We compared 62 patients randomized to polyamide suture closure of an office hand and upper extremity incision (mostly carpal tunnel release and trigger finger release) to 50 patients closed with Chromic gut suture. Patients rated overall treatment satisfaction, satisfaction with initial healing, pain intensity, and upper extremity-specific activity tolerance. RESULTS: Accounting for potential confounding in multivariable linear and logistic regression analysis, we found the following: (1) overall satisfaction with care was unrelated to suture type; (2) satisfaction with initial wound healing and appearance was lower among people with no other comorbidities, but unrelated to suture type; (3) there were no factors independently associated with pain intensity; and (4) excisional biopsy was associated with greater activity tolerance. CONCLUSIONS: Our findings suggests that Chromic sutures are a viable alternative to polyamide sutures after office hand surgery, provided that the care team anticipates and develops strategies for concerns that may arise if the sutures take an extended period to fall off. TYPE OF STUDY/LEVEL OF EVIDENCE: Therapeutic II.

Prostatic metaplasia and pilar differentiation in gender-affirming mastectomy specimens.

With the increasing practice of gender-affirming mastectomy as a therapeutic procedure in the setting of gender dysphoria, there has come a profusion of literature on the pathologic findings within these specimens. Findings reported in over 1500 patients have not included either prostatic metaplasia or pilar metaplasia of breast epithelium. We encountered both of these findings in the course of routine surgical pathology practice and therefore aimed to analyze these index cases together with a retrospective cohort to determine the prevalence, anatomic distribution, pathologic features, and associated clinical findings of prostatic metaplasia and pilar metaplasia in the setting of gender-affirming mastectomy. In addition to the 2 index cases, 20 additional archival gender-affirming mastectomy specimens were studied. Before mastectomies, all but 1 patient received testosterone cypionate, 6/22 patients received norethindrone, and 21/22 practiced breast binding. Prostatic metaplasia, characterized by glandular proliferation along the basal layer of epithelium in breast ducts, and in one case, within lobules, was seen in 18/22 specimens; 4/22 showed pilar metaplasia, consisting of hair shafts located within breast ducts, associated with squamoid metaplasia resembling hair matriceal differentiation. By immunohistochemistry, prostatic metaplasia was positive for PSA in 16/20 cases and positive for NKX3.1 in 15/20 cases. Forty-three reduction mammoplasty control cases showed no pilar metaplasia and no definite prostatic metaplasia, with no PSA and NKX3.1 staining observed. We demonstrate that prostatic metaplasia and pilar metaplasia are strikingly common findings in specimens from female-assigned-at-birth transgender patients undergoing gender-affirming mastectomy. Awareness of these novel entities in the breast is important, to distinguish them from other breast epithelial proliferations and to facilitate accrual of follow-up data for better understanding their natural history.

Large cell calcifying Sertoli cell tumour: a contemporary multi-institutional case series highlighting the diagnostic utility of PRKAR1A immunohistochemistry.

AIMS: Large cell calcifying Sertoli cell tumour (LCCSCT) is a rare testicular sex cord-stromal tumour that primarily affects young patients and is associated with Carney complex. We sought to characterise the clinicopathological features of a series of LCCSCT and evaluate the diagnostic utility of PRKAR1A immunohistochemistry (IHC). METHODS AND RESULTS: The LCCSCT cohort (n = 15) had a median age of 16 years (range = 2-30 years). Four patients were known to have Carney complex. PRKAR1A IHC was performed in each case. For comparison, PRKAR1A IHC was also assessed in other sex cord-stromal tumours, including Sertoli cell tumour, not otherwise specified (SCT, NOS; n = 10), intratubular large cell hyalinising Sertoli cell tumour (n = 1) and Leydig cell tumour (n = 23). Loss of cytoplasmic PRKAR1A expression was observed in all but one LCCSCT (14 of 15; 93%). PRKAR1A expression was retained in all SCTs, NOS (10 of 10; 100%), the majority of Leydig cell tumours (22 of 23; 96%) and an intratubular large cell hyalinising Sertoli cell tumour (1 of 1; 100%). One Leydig cell tumour showed equivocal staining (multifocal weak expression). CONCLUSIONS: Overall, PRKAR1A loss is both sensitive (93%) and highly specific (97%) for the diagnosis of LCCSCT. PRKAR1A loss may aid its diagnosis, particularly in sporadic cases and those that are the first presentation of Carney complex.

Belzutifan, a Potent HIF2α Inhibitor, in the Pacak-Zhuang Syndrome.

The integration of genomic testing into clinical care enables the use of individualized approaches to the management of rare diseases. We describe the use of belzutifan, a potent and selective small-molecule inhibitor of the protein hypoxia-inducible factor 2α (HIF2α), in a patient with polycythemia and multiple paragangliomas (the Pacak-Zhuang syndrome). The syndrome was caused in this patient by somatic mosaicism for an activating mutation in EPAS1. Treatment with belzutifan led to a rapid and sustained tumor response along with resolution of hypertension, headaches, and long-standing polycythemia. This case shows the application of a targeted therapy for the treatment of a patient with a rare tumor-predisposition syndrome. (Funded by the Morin Family Fund for Pediatric Cancer and Alex's Lemonade Stand Foundation.).