bluuebunny/crossref_metadata_2025_split huggingface dataset:
A 64-Year-Old Woman With Posttransplant Hepatitis
Authors: Hardy Naomi , Twaddell William S. 
Published: September 2023

Abstract
Abnormal liver function tests and nonspecific histopathologic findings are relatively common in the post–liver transplant setting. Whereas some cases remain idiopathic and many resolve spontaneously, some carry a risk of chronicity and long-term liver dysfunction including cirrhosis, graft loss, and death. Accurate assessment and follow-up of such findings are therefore crucial in this population.
We report a case of a 64-year-old woman who underwent liver transplantation for chronic hepatitis C infection with cirrhosis. Several months after transplantation, she underwent a liver biopsy as part of a workup for abnormal serologic studies and transaminase elevation. The biopsy showed nonspecific hepatitis. Eventually, additional serologic testing demonstrated hepatitis E viral infection.
Causes of hepatitis and other forms of posttransplant liver disease, including hepatitis E, are discussed.
Liver Transplant in a 71-Year-Old Man With a Diagnosis of Nonalcoholic Steatohepatitis
Authors: Twaddell William S. 
Published: September 2023

Abstract
Fatty liver disease is an increasingly common indication for liver transplantation. Because of its prevalence, it may coexist with other causes of chronic liver disease, many of which may carry implications for treatment or follow-up of patients or their families. An increased degree of suspicion may be required to detect concurrent liver disease. We report a case of a 71-year-old man who underwent liver transplantation for nonalcoholic steatohepatitis. The explanted liver showed evidence of coexisting α1-antitrypsin deficiency disorder. The clinicopathologic features and epidemiology of fatty liver disease and α1-antitrypsin deficiency disorder are discussed, along with other possible coexisting disease.
Incidental Hepatic Granulomas in a Young Woman
Authors: Weidner Anna-Sophie 
Published: September 2023

Abstract
Hepatic granulomas are identified in approximately 3% to 4% of liver biopsies in the Western world. Their presence raises a broad differential diagnosis for the pathologist to consider, including infectious, immune-mediated, and drug-induced etiologies. Certain histologic features of granulomas and the adjacent liver parenchyma can help narrow the differential diagnosis, although clinical and laboratory correlation is often necessary to establish a definitive diagnosis. The purpose of this article is to review the morphologic classification of hepatic granulomas and to discuss hepatic sarcoidosis, one of the most common immune-mediated causes.
Histopathologic Approach to Cholestatic Diseases of the Liver
Authors: Jessurun Jose 
Published: September 2023

Abstract
Liver biopsy specimens of patients with cholestatic diseases pose a challenge to pathologists since, in most instances, this procedure is performed in a selected group of patients in whom clinical, laboratory, and imaging studies are inconclusive. Proper interpretation of the various histologic features is facilitated by the recognition of the most common patterns, which correlate with a defined group of diseases. Cholestatic disorders are grouped in 2 broad categories: acute and chronic. Four histologic patterns with different clinical implication are recognized within the first category: (1) ductular reaction, (2) pure canalicular cholestasis, (3) cholestasis with intrahepatic bile duct disease, and (4) cholestatic hepatitis. Chronic disorders are recognized by portal-based fibrosis, Mallory-Denk bodies, cholate stasis, accumulation of copper or copper-binding proteins, and biliary-type cirrhosis. Immunohistochemical reactions for cytokeratin 7 help to identify damaged bile ducts, highlight reactive ductules, and, most importantly, provide support for a cholestatic disorder by the staining of periportal hepatocytes (intermediate phenotype). The histologic features of primary biliary cholangitis and primary sclerosing cholangitis are reviewed with special emphasis on overlap syndromes and other entities that enter in the differential diagnosis.
Human Polyomavirus 7 and WU Polyomavirus-Associated Lymphocytic Bronchitis/Bronchiolitis in Native and Allograft Lung Biopsies From Immunocompromised Patients: Report of 3 Cases and Review of Literature
Authors: Mehrad Mitra , Trejo Bittar Humberto E. , Yousem Samuel A. 
Published: September 2023

Abstract
Human polyomavirus (PyV) family comprised 13 DNA viruses, which cause subclinical infection in more than 90% of the general population. However, significant disease including cancer is mainly observed in immunosuppressed patients. Few studies have investigated the detection of PyV in the respiratory tract. In this report, 3 transbronchial biopsies showed viral inclusions on histologic examination and were evaluated for anti-SV40 large T antigen (SV40 T Ag) by immunohistochemistry (IHC), in situ hybridization, and viral genome sequencing by polymerase chain reaction. Patients 1 and 2 were immunosuppressed lung transplant recipients. Patient 1 presented with diffuse pruritic rash and respiratory failure, and patient 2 with PyV viremia. Patient 3 had chronic lymphocytic leukemia/small lymphocytic lymphoma and presented with cough and shortness of breath. Histologic examination of all 3 lung biopsies were similar and revealed predominantly bronchial epithelial cells with enlarged nuclei, smudgy chromatin quality, and lymphocytic bronchitis/bronchiolitis with a patchy alveolar septal mononuclear infiltrate. SV40 large T antigen IHC was positive in all cases, whereas in situ hybridization for BK and JC virus was negative. Polymerase chain reaction sequencing identified PyV7 in case 1 and WUPyV in cases 2 and 3. We describe for the first time that PyV7 and WUPyV may be associated with lymphocytic bronchitis/bronchiolitis in the lungs of immunosuppressed individuals. It is important to be cognizant of the cross-reactivity of SV40 T Ag IHC with other types of PyV and equally essential to distinguish PyV bronchitis from other viral pathogens.
Phosphaturic Mesenchymal Tumor: A Single Case Report Discussing Diagnostic and Therapeutic Challenges of Tumor-Induced Osteomalacia
Authors: Homlar Kelly , Sullivan Brian T. , Sharma Suash 
Published: September 2023

Abstract
Phosphaturic mesenchymal tumor is a rare neoplasm that produces fibroblast growth factor 23 resulting in the paraneoplastic tumor-induced osteomalacia. Patients are typically diagnosed several years after the first signs of bone pain, fatigue, and weakness; the non-specific character of the symptoms often delays the diagnosis and curative surgical treatment. The following case report details a classic presentation of a phosphaturic mesenchymal tumor of mixed connective tissue type involving the right posterior tibialis muscle with erosion of the adjacent medial fibular cortex. The patient underwent a surgical resection and is currently asymptomatic. This report highlights the need for multidisciplinary diagnostic effort, effectiveness, of early surgical intervention, and emphasizes the importance of including this rare but damaging disease process in the differential diagnosis of osteomalacia.
Isolated Pulse Granuloma in a Mesenteric Lymph Node: Unusual Nodal Manifestation Associated With Crohn Disease Complicated by Ileal Adenocarcinoma
Authors: Medlicott Shaun A. C. , Eidus Leslie , Trpkov Kiril 
Published: September 2023

Abstract
Pulse granuloma is an unusual inflammatory reaction to legumes. Pulse granulomas of the gastrointestinal tract are typically accompanied by significant mural damage due to ulceration, fistula, or perforation. We describe a solitary pulse granuloma in a mesenteric lymph node of a 74-year-old male patient with Crohn disease, who presented with an ileal adenocarcinoma, but without demonstrable fistula or perforation. To our knowledge, this is only the second reported example of Crohn disease associated with a pulse granuloma in a mesenteric node and also only the second example of a nodal location for any documented pulse granuloma. We postulate that mesenteric lymph node pulse granuloma may represent a unique and unusual type of morphology associated with Crohn disease.
Brown Bowel Syndrome Presenting as a Small Bowel Obstruction
Authors: Alwatari Yahya , Preciado Christopher , Tondon Rashmi , Shiroff Adam 
Published: September 2023

Abstract
Brown bowel syndrome (BBS) is a rare condition characterized by lipofuscin deposition in the muscularis propria of the bowel. It is associated with vitamin E deficiency and malabsorptive syndromes. We report a case of BBS in a patient with previously undiagnosed primary intestinal lymphangiectasia. The patient had a longstanding history of malnutrition as well as bilateral lower extremity lymphedema and chylous ascites. He presented to our hospital with small bowel obstruction (SBO). Initial magnetic resonance enterography revealed a dilated duodenum, which when biopsied revealed only lymphangiectasia and lymphedema. He was managed conservatively and discharged following resolution of the obstruction. The patient presented again 1 month later with SBO that failed to resolve with conservative treatment. Subsequent exploratory laparotomy discovered a portion of pale, edematous, aperistaltic jejunum. The specimen was resected, and pathologic examination revealed brown granular pigment deposition within the muscularis propria, which was highlighted by periodic acid–Schiff and lipofuscin stains, diagnostic of BBS. Nutritional workup revealed multiple deficiencies. The patient's clinical findings and history were suggestive of primary intestinal lymphangiectasia with resulting nutritional deficiencies leading to BBS. Outpatient follow-up after recovery revealed an elevated 24-hour fecal α1 antitrypsin, which supports this diagnosis. The patient has since improved following adherence to a low-fat diet. The combined clinical, radiographic, and pathologic findings in this case allowed for the resolution of this complex diagnostic dilemma. Although rare, BBS remains an important consideration in the differential diagnosis of a patient with SBO and history of chylous ascites and should be viewed as a symptom of underlying treatable nutritional deficiency.
Poorly Differentiated/Anaplastic Chordoma in a Child—Case Report and Review of the Literature
Authors: Morbeck Diogo Lago , Batista Patricia Marquis Dornelas , Tregnago Aline Caldart , Cabrera Rafael Adame , Costa Felipe D’Almeida , Kalil Ricardo Karam 
Published: September 2023

Abstract
Chordomas are rare bone tumors, with highest incidence after the age of 40 years. When they occur in infants and toddlers, they usually are poorly differentiated/anaplastic chordomas with characteristic histopathologic presentation and unique molecular changes such as the lack of expression of SMARCB1/INI1. We present the case of a 3-year-old girl with a 5.0-cm sacrococcygeal mass. Magnetic resonance imaging showed a lobulated, heterogeneous mass attached to S5. Chordomas are very rare at this age; therefore, it is very important to distinguish this tumor from other more common neoplasms that occur in this location and age range because when they are identified their immunogenetic profile may suggest a worse prognosis. Histological, immunohistochemical, molecular characteristics, and differential diagnosis of this variant of chordoma are discussed.
Primary Renal Well-differentiated Neuroendocrine Tumor—Report of a Case With Cytological-Histopathologic Correlation and Review of Literature
Authors: Manucha Varsha , Azar Azniv , Roda Manohar , Lewin Jack 
Published: September 2023

Abstract
Renal well-differentiated neuroendocrine tumor (WDNET; also known as carcinoid), although considered as a distinct entity in the World Health Organization classification, continues to be an enigma to the pathologists and clinicians because of its rarity. In this case report, we describe a case of primary renal WDNET in a 54-year-old man. The tumor was initially diagnosed as a urothelial carcinoma. After a second review and a broad-spectrum immunopanel, a revised diagnosis of WDNET was rendered.
Expanding the Spectrum of Ciliated Muconodular Papillary Tumor of the Lung: A Case Showing Nonpapillary and Purely Glandular Morphology
Authors: Baratelli Felicita , Wei Christina , Elatre Wafaa , Xiao Guang-Qian , Ward Pamela , Pettersson Jonas , Campan Mihaela , Larsen Brandon T. , Ashley Prosper , Wang Linan , Cohen Robbin , Koss Michael 
Published: September 2023

Abstract
We report an unusual case of a subpleural bronchiolar/glandular proliferation in a 76-year-old Hispanic woman with microscopic features reminiscent of those of the so-called ciliated muconodular papillary tumor (CMPT). The lesion presented radiologically as a solitary subpleural nodule measuring 2.7 × 1.2 cm with low standard uptake value (SUV) of 1.4. Microscopically, it was circumscribed but unencaspulated and consisted of mucous-filled spaces lined by cytologically bland cuboidal to low columnar cells, including goblet cells and ciliated epithelium, with underlying nodular collections of basaloid cells. The lining cells stained diffusely for CK7 but only focally for TTF-1 and CEA, whereas the basal cells expressed CK5/6. Ki-67 showed a proliferative index of less than 1%. Target gene mutation analysis with a 50-cancer-related-gene panel using next-generation sequencing showed the bronchiolar proliferation to harbor an EGFR in frame exon 20 insertion mutation with 30% allele frequency, which supports a neoplastic diagnosis. Accordingly, given the mutually exclusive nature of driver mutations, a BRAF V600E mutation was absent by both immunohistochemical and next-generation sequencing analysis. Microscopic evidence of metastatic spread was not seen in 8 regional lymph nodes examined. Given the histomorphology and immunohistochemical findings, the mutational profile and the reported heterogeneous microscopic patterns of CMPTs, including glandular component, we suggest the tumor herein described be a glandular variant of CMPT. We therefore suggest that the term ciliated muconodular tumor may be more appropriate for this group of lesions.
Case Report: Benign Phyllodes Tumor of the Vulva
Authors: Vella Josefa E.O. , Thomas Michael P. , Singh Ruchira , Shaaban Abeer M. 
Published: September 2023

Abstract
Phyllodes tumor of the vulva is a rare tumor and is histologically similar to phyllodes tumor of the breast. Morphological and immunohistochemical features of a case are presented here.
RET/PTC1 Rearrangement in Hashimoto Thyroiditis: Canonical WNT Expression Up-regulation for Neoplastic Promotion
Authors: Al-Hashimi Fatima , Diaz-Cano Salvador J. 
Published: September 2023

Background
More than half a century has passed since the association between papillary thyroid carcinoma (PTC), and Hashimoto thyroiditis (HT) has been described. The discovery of the RET/PTC oncogene 30 years later has further strengthened this argument, followed by the associations made between hyalinizing trabecular adenoma (HTA) and both PTC and HT. Numerous researchers studied these relationships, with some debating a valid link.

Findings
This case of a 28-year-old woman with HT-associated PTC and a coexisting HTA offers a unique opportunity to study these three lesions together in the same microenvironment. Fresh tissue analysis for gene expression showed that all three expressed RET/PTC1 transcripts, whereas this was not seen in the control normal thyroid tissue. There was also an increased expression of AKT, ERK1, nuclear β-catenin, and TCF4 in both the HTA and PTC sampled tissue. AKT plays a central role in regulating cell proliferation and survival by inhibiting apoptotic processes, whereas ERK1 leads to cell proliferation. Both β-catenin and TCF4 are linked to the canonical WNT/β-catenin pathway.

Conclusions
The expression of RET/PTC1 highlights the link between inflammatory processes such as HT and neoplastic conditions such as HTA and PTC. The limited expression of TCF4, AKT, ERK1, and β-catenin supports the notion that the canonical WNT/β-catenin pathway plays a pivotal role in the development of this neoplasm. It is important to note that at this time, gene expression alone is not sufficient to make a distinction between benign and malignant thyroid lesions.
Role of Dynamic Markers in the Molecular Testing of Indeterminate Thyroid Nodules
Authors: Banizs Anna B. , Toney Nicole A. , Jackson Sara A. , Narick Christina M. , Silverman Jan F. , Finkelstein Sydney D. 
Published: September 2023

Abstract
Molecular testing of fine-needle aspirates of indeterminate thyroid nodules is now standard and consists mainly of mutational analysis of the most frequent point mutations and chromosomal rearrangements occurring in advanced thyroid tumors with the goal of determining these genetic alterations early in the neoplastic process. However, mutation panels, even extended ones, face challenges; namely, genetic alterations in cytologically indeterminate categories are represented at relatively low percentage, and with the exception of strong driver mutations, the mere presence of a mutation does not reliably predict malignancy.
Currently, dynamic markers such as microRNAs (miRNAs) are being explored to overcome the limitations of mutational panels. Various stages of neoplasia are associated with characteristic patterns of deregulated miRNAs, making them attractive candidates as predictive markers. In this review, we summarize current knowledge from the literature about the potential role of miRNAs in risk stratification of indeterminate thyroid nodules, including our findings based on a large molecular database of fine-needle thyroid aspirates. We believe miRNA classifiers and mutational analysis in combination are powerful tools in the risk stratification of indeterminate thyroid nodules.
Cytology Slides for Molecular Analysis Can Address Both Interobserver Variability and Sample Heterogeneity: Overview of Thyroid Molecular Testing
Authors: Narick Christina M. , Toney Nicole A. , Kumar Gyanendra , Finkelstein Sydney D. 
Published: September 2023

Abstract
Studies have shown that a high degree of inter and intraobserver variability, in addition to the heterogeneity of the sample itself, can inhibit the accuracy of cytopathological assessment of thyroid nodules. Guidelines have recommended the use of molecular analysis, used in conjunction with cytology, to assist in the guidance of patient management. Currently, there are several commercially available molecular tests offered to better assess overall malignancy risk, each now with updated and expanded capability. The collaboration between molecular pathology and cytopathology is critical to better understand the biology of these lesions and help clinicians optimize patient management and surgical decisions.
Sarcomatoid Hepatocellular Carcinoma: A Case Report and Review of the Differential Diagnosis of Malignant Spindle Cell Lesions of the Liver
Authors: Stashek Kristen M. , White Rachel , Song Linda , Tondon Rashmi , Kallen Michael , Twaddell William 
Published: September 2023

Abstract
Sarcomatoid hepatocellular carcinoma is a rare aggressive variant of hepatocellular carcinoma that typically shows a conventional component of hepatocellular carcinoma admixed with a malignant spindle cell proliferation. In small biopsy specimens, the conventional component may not always be present; therefore, knowledge of the differential diagnosis of malignant spindle cell lesion presenting in the liver is necessary to ensure accurate diagnosis.
Incidental Collision Tumor: Two Common Metastases Meet in the Neck
Authors: Kallen Michael E. , White Rachel , Hittman Jamie , Hatten Kyle M. , Stashek Kristen M. , Staats Paul N. , Papadimitriou John C. 
Published: September 2023

Abstract
Human papillomavirus (HPV)–positive oropharyngeal squamous cell carcinoma is a biologically and clinically distinct type of head and neck cancer, featuring a generally improved prognosis over its HPV-negative counterparts. Papillary thyroid carcinoma is the most common thyroid malignancy and has a high frequency of regional lymph node metastasis and generally indolent clinical behavior. We present a case of intranodal collision between HPV-positive oropharyngeal squamous cell carcinoma and incidental papillary thyroid carcinoma. These two common lesions of the head and neck highlight an emergent area of complicated histology and raise interesting questions about tumor biology. We briefly review the variations of composite lesions described in the head and neck, as well as the potential prognostic implications between different types and role of ancillary testing and molecular diagnostics in their separation.
Aggressive Variants of Follicular- and Parafollicular-Derived Thyroid Carcinoma
Authors: Rossi Esther Diana , Faquin William C. , Pantanowitz Liron 
Published: September 2023

AbstractThere are several aggressive variants of thyroid carcinoma including those of papillary thyroid carcinoma, poorly differentiated thyroid carcinoma, anaplastic thyroid carcinoma, and medullary thyroid carcinoma that are important to recognize. Among thyroid malignancies, papillary thyroid carcinoma represents the most common form of endocrine cancer. Papillary thyroid carcinoma usually presents as an indolent cancer with high overall survival rates approaching 96%. However, a minority of thyroid carcinomas with distinctive histopathology (eg, tall cell, columnar cell, solid, hobnail, diffuse sclerosing, and diffuse follicular variant) behaves more aggressively and may not respond to routine treatment, leading to higher mortality. Other aggressive follicular-derived thyroid malignancies are represented by poorly differentiated thyroid carcinoma and anaplastic thyroid carcinoma, which are associated with an especially unfavorable prognosis. The most important aggressive parafollicular thyroid malignancy encountered is medullary thyroid carcinoma. This review describes the clinical, pathological, and molecular findings for these aggressive thyroid malignancies and underscores current concepts and controversies related to these tumors.
Histopathology of Encapsulated Follicular-Patterned Thyroid Tumors
Authors: Elsheikh Tarik M. 
Published: September 2023

Abstract
Encapsulated follicular-patterned thyroid tumors remain diagnostically challenging for pathologists, including experts. The differential diagnosis typically includes hyperplastic/adenomatous nodule, follicular adenoma, follicular thyroid carcinoma, and follicular variant of papillary thyroid carcinoma (FVPTC). Noninvasive follicular thyroid neoplasm with papillary-like features is a new terminology that was recently proposed for a subset of noninvasive FVPTC that has a highly favorable outcome and can be treated in a conservative manner. This is in contrast to invasive-encapsulated FVPTC that clinically behaves similar to follicular thyroid carcinoma and infiltrative FVPTC that behaves like classic PTC. In this review, the differential diagnosis of encapsulated follicular-patterned thyroid neoplasms is discussed, including noninvasive follicular thyroid neoplasm with papillary-like features and its recently revised pathologic criteria. Commonly encountered diagnostic challenges and pitfalls are also reviewed, including criteria for capsular and vascular invasion and minimal diagnostic features of papillary thyroid carcinoma.