Cancer of Unknown Primary: When Imaging, Pathology, and Molecular Biology Do Not Match.

Introduction: Cancers of unknown primary are aggressive and rare malignancies with a complex diagnosis and management. Here we present a case in which imaging, pathology, and molecular biology did not match for a specific tumor site and the importance of a multidisciplinary team for these complicated cases. Case Presentation: A man in his 70s with strong smoking history under workup for suspicion of metastatic lung cancer underwent lung mass biopsy. Immunohistochemical stains corresponded to hepatocellular/cholangiocarcinoma or germ cell tumor; however, dedicated liver and testicular studies including imaging and iscochrome 12p FISH were negative. Additionally, somatic variant profiling was not specific for any malignancy nor targetable variants. Given the pattern of disease, risk factors, and patient history, the patient received treatment for lung adenocarcinoma (carboplatin, pemetrexed, and pembrolizumab). The patient had a drastic improvement in dyspnea, weight gain, and was able to return to work. Conclusion: This report describes a case in which immunohistochemistry and molecular profiling did not identify the tissue of origin and highlights the importance of a multidisciplinary team to reach a diagnosis and guide treatment without delaying patient care in patients with these diagnoses.

Characterising the challenges of managing difficult red blood cell alloantibodies in liver transplant recipients.

AIMS: Formation of red blood cell alloantibodies (RBCAs) complicates transfusion support in liver transplantation (LT). Difficult RBCAs (DAs, >3 antibodies or antibodies for which <25% donors are antigen negative) further challenge care. This study characterises DA outcomes relative to non-difficult RBCAs (NDAs). METHODS: Single-centre, retrospective analysis of LT patients (2002-2021). RBCAs were defined as clinically significant antibodies. DAs were compared with NDAs. RESULTS: 89 patients had clinically significant RBCAs (DA=50, NDA=39). More DAs were anti-Jka, anti-M; fewer were anti-E, anti-K (all p<0.05). DA patients often had multiple antibodies (44% vs 12.8% NDA, p=0.0022). Probability of finding antigen-negative blood was lower for DAs (17.4% vs 68.1% NDA, p<0.0001) as was RBCs received (9.4 vs 14.7 units in NDA, p=0.0036). Although survival was similar, patients with DAs had more adverse reactions (8% vs 0%, p=0.128). Some antibodies appeared to occur with specific liver diseases (such as primary sclerosing cholangitis, alcoholic steatohepatitis and recurrent disease); however, due to low sample size, definitive conclusions cannot be made. CONCLUSIONS: DA LT recipients contain >1 RBCA, have a lower probability of finding antigen negative blood and may experience more adverse transfusion event (ATE). Despite this, the incidence of ATEs was still quite low.

Laryngeal Ganglioneuromatosis in a Child With Multiple Endocrine Neoplasia Type 2B (MEN2B): Case Report and Review of Literature.

Multiple Endocrine Neoplasia type 2B (MEN2B) is an autosomal dominant cancer syndrome caused by a mutation in rearranged during transfection (RET) proto-oncogene and includes medullary thyroid carcinoma, pheochromocytoma, gastrointestinal neuromas, and mucosal ganglioneuromas. Medullary thyroid carcinoma is the major cause of mortality in MEN2B syndrome. Medullary thyroid carcinoma can often appear during the first years of life. While mucosal neuromas in MEN2B are common, laryngeal neuromas are extremely rare. We present a third case of a pediatric patient with a laryngeal neuroma localized to the left true vocal cord and conduct a literature review of vocal cord neuromas in MEN2B patients.

From principles to practice: Implementation of entrustable professional activities (EPAs) for surgical pathology residency education in a large academic hospital.

Over the past decade, competency-based medical education (CBME) has gained momentum in the United States to develop trainees into independent and confident physicians by the end of their training. Entrustable professional activities (EPAs) are an established methodology for assessing trainee development through an outcomes-driven rather than a time-based model. While EPAs have been utilized as an assessment tool for CBME in Europe and Canada, their validation and implementation in some medical specialties has occurred more recently in the United States. Pediatrics was the first specialty in the US to conduct a large-scale UME-GME pilot. Pathology Residency EPAs were published in 2018; however, implementation in training programs has been slow. We have piloted EPAs in our residency program's surgical pathology rotation and propose a unique set of 4 surgical pathology EPAs to track trainee preparedness for independent practice.

A novel 6-day cycle surgical pathology rotation improves resident satisfaction and maintains Accreditation Council for Graduate Medical Education (ACGME) milestone performance.

Surgical pathology residency training in the United States lags behind other specialties in quality control and graduated responsibility to train independent pathologists capable of seamlessly entering practice after training. We observed that our traditional 3-day-cycle surgical pathology cycle (day 1-grossing; day 2 -biopsies/frozens/preview; day 3 - sign-out) consistently and negatively impacted resident education by reducing preview time, case follow-up, immunohistochemical stain (IHC) interpretation, and molecular study integration. We aimed to create a modern surgical pathology rotation that improved performance and outcomes. We innovated our rotation to enhance resident education and ensure graduated responsibility. A novel 6-day cycle was created composed of 2 grossing days, 1 frozens/biopsies/preview days, 2 dedicated sign-out days, and 1 frozens/biopsies/case completion day. Residents completed surveys before implementing the new rotation and 6 months after implementation to track self-assessment of Accreditation Council for Graduate Medical Education (ACGME) milestone performance and internal quality control metrics. Clinical Competency Committee (CCC) annual evaluations were assessed in paired PGY levels pre- and post-intervention. After implementation, there was a statistically significant improvement in self-assessment of levels 4 and 5 of ACGME milestones and improved satisfaction of quality metrics, including time for previewing, reviewing IHC, graduated responsibility, and perceived readiness for independent practice. CCC evaluations showed overall maintained performance levels, with trends towards improvements in junior resident classes. Our 6-day cycle adequately fulfills the current demands of our sizeable academic center's surgical pathology training and can be a model for pathology residencies looking to modernize their surgical pathology rotations and resident education.

Future prospects for the clinical transfusion of pig red blood cells.

Transfusion of allogeneic human red blood cell (hRBCs) is limited by supply and compatibility between individual donors and recipients. In situations where the blood supply is constrained or when no compatible RBCs are available, patients suffer. As a result, alternatives to hRBCs that complement existing RBC transfusion strategies are needed. Pig RBCs (pRBCs) could provide an alternative because of their abundant supply, and functional similarities to hRBCs. The ability to genetically modify pigs to limit pRBC immunogenicity and augment expression of human 'protective' proteins has provided major boosts to this research and opens up new therapeutic avenues. Although deletion of expression of xenoantigens has been achieved in genetically-engineered pigs, novel genetic methods are needed to introduce human 'protective' transgenes into pRBCs at the high levels required to prevent hemolysis and extend RBC survival in vivo. This review addresses recent progress and examines future prospects for clinical xenogeneic pRBC transfusion.

Alloimmunization Against RBC Antigens Is Not Associated With Decreased Survival in Liver Transplant Recipients.

BACKGROUND: Improvement of liver transplantation (LT) outcomes requires better understanding of factors affecting survival. The presence of RBC alloantibodies (RBCAs) on survival in LT recipients was evaluated. METHODS: This study was a single-center, retrospective cohort study reviewing transfusion records and all-cause mortality between 2002 and 2021. RESULTS: Between 2002 and 2021, 2079 LTs were completed, 1,396 of which met inclusion criteria (1,305 RBCA negative; 91 RBCA positive [6.5%]). The cohorts were similar in age (mean [range], 55.8 [17-79] years vs 56.8 [25-73] years; P = .41, respectively) or sex (RBCA negative, 859 [65%] men and 446 [35%] women vs RBCA positive, 51 [56%] men and 40 [44%] women; P = .0684). Of 132 RBCAs detected, 10 were most common were to E (27.27%), Jka (15.91%), K (9.09%), C (8.33%), M (6.06%), D (5.3%), Fya (4.55%), e (2.27%), c (2.27%), and Jkb (2.27%). Twenty-seven patients (29.7%) had more than 1 RBCA; the most common combinations were C with Jka (7.4%) and E with Dia (7.4%). All-cause mortality was increased in men (men, 14.45 years vs women, 17.27 years; P = .0266) and patients 65 years of age and older (≥65 years of age, 10.21 years vs <64 years of age, 17.22 years; P < .0001). The presence of RBCA (≥1) did not affect all-cause mortality (RBCA negative, 14.17 years vs RBCA positive, 15.29 years; P = .4367). The top 5 causes of death were infection (11.9%), primary malignancy (solid) (10.8%), recurrent malignancy (10.5%), cardiovascular arrest (7.1%), and pulmonary insufficiency/respiratory failure (5.7%). CONCLUSIONS: Survival in RBCA-positive LT recipients is no different from that in RBCA-negative LT recipients.

Video-Based Education Improves Sampling (Grossing) Confidence in Pathology Trainees.

CONTEXT.­: Pathology resident education has a steep learning curve. Specimen sampling (grossing) is a procedural task, and procedural fields add video materials to their curricula to familiarize trainees with procedure(s), reduce errors, and improve patient care. Our team applied this strategy to develop original in-house sampling videos for our program. OBJECTIVES.­: To evaluate the effect of in-house sampling videos on resident sampling confidence. DESIGN.­: Sampling videos covering all major organ systems (AMOS) were created for our postgraduate year 1 (PGY1) trainees. Videos were hosted on a Northwestern cloud server for on-demand access. Trainees completed 3 surveys (0, 6, 12 months) evaluating sampling confidence comparing those who used in-house videos as an educational supplement with those who did not use the videos. RESULTS.­: Sampling confidence significantly improved at 6 and 12 months (P < .001) across AMOS and PGY levels. When compared with those who did not use in-house sampling videos, trainees who supplemented their education with in-house sampling videos had significantly higher confidence ratings across AMOS and PGY levels at the start of the study (P < .001) and at 6 months (P = .004). Sampling confidence significantly improved for PGY1 trainees at 6 and 12 months (P < .001); for PGY2 and PGY3 trainees, confidence significantly improved at 6 months (P < .001). When evaluated by organ-specific analyses, sampling and teaching confidence improved across all organ systems and, except for the gastrointestinal system, reached significance at 12 months for all PGY levels. CONCLUSIONS.­: Sampling videos, when used as a supplement to the existing curriculum, significantly improved trainee confidence.

Validation of the Milan system for reporting salivary gland cytopathology: a single institution's 10-year experience.

INTRODUCTION: Fine needle aspiration cytology is often used for the initial diagnosis and management of patients with salivary gland tumors. Because of its global usage, a consensus classification schema was devised in 2018 to initiate universal reporting of salivary gland cytology specimens, termed the Milan system for reporting salivary gland cytopathology (MSRSGC) and composed of distinct diagnostic categories. Few retrospective studies have been undertaken to review the MSRSGC within institutions. MATERIALS AND METHODS: We analyzed salivary gland fine needle aspirations during a 10-year span from 2011 to 2021, categorized each cytology case to fit the MSRSGC, and subsequently reviewed the corresponding surgical resections, if indicated, to determine the rate of malignancy (ROM) and rate of neoplasia. RESULTS: Our ROM was higher (>10%) for the following MSRSGC categories: non-neoplastic, atypia of undetermined significance, and suspicious for malignancy. Also, our data correlated well with the following MSRSGC categories: nondiagnostic, neoplasm-benign, salivary gland neoplasm of uncertain malignant, and malignant. CONCLUSIONS: Although the data were indicative of the ROM for surgically resected salivary gland lesions, the ROM for non-neoplastic lesions could truly be lower given that most lesions in this category will not undergo surgical resection. Additionally, determination of the rate of neoplasia could a tool that could be used to further guide our clinical colleagues.

The Frequency of Focal Cortical Dysplasia-Like Histologic Features Near Adult-Type Diffuse Gliomas.

While the coexistence of focal cortical dysplasia (FCD) and grade 1 noninfiltrative gliomas has been described, to date, only rare case reports have described FCD adjacent to infiltrating gliomas. We therefore sought to determine how often FCD-like findings occur near adult-type diffuse gliomas. This was a retrospective survey of 186 consecutive, newly diagnosed, en bloc glioma resections. Fifty-nine (31.7%) had sufficient adjacent cortex to evaluate for FCD-like features. Among IDH mutant ("IDHmut") gliomas, 40/77 (52%) had adjacent evaluable cortex, whereas only 19/109 (17%) of IDH wild-type ("IDHwt") gliomas did (p < 0.0001). Among cases with evaluable cortex, 15 (25.4%) contained features suggestive of FCD, including radial/tangential dyslamination and/or maloriented neurons. In a multivariable analysis, increasing glioma grade (OR = 4.0, 95% CI = 1.2-13.5, p = 0.027) and IDHmut (OR = 6.5, 95% CI = 1.3-32.2, p = 0.022) emerged as independently positive correlates with the appearance of FCD-like findings. However, FCD-like features were also found in 13/32 (40.6%) cortical samples from adult brains without any neoplastic disease or seizure histories (p = 0.16). Together, these data suggest that, while FCD-like histologic features can be incidentally found in at least a subset of diffusely infiltrative gliomas, the frequencies are not significantly different from that seen in otherwise non-neoplastic brains, and are therefore most likely nonpathologic.

Rapid 3D reconstruction guided embolization for catastrophic bleeding following vacuum assisted breast biopsy; A case report and review of the literature.

The most clinically significant complication associated with stereotactic core needle biopsy of the breast is hematoma formation, which only occurs in less than 1% of biopsies and may require treatment. Cases of uncontrollable bleeding, refractory to repeated compression, resulting from biopsy are exceedingly rare. We present a case of catastrophic, uncontrollable bleeding and large hematoma formation resulting from stereotactic vacuum-assisted breast biopsy of a breast mass identified in screening mammography. Percutaneous embolization was planned and guided using 3D reconstructions from computed tomographic angiography, and bleeding was successfully controlled with micro-coil embolization.

Liver Pathology and SARS-CoV-2 Detection in Formalin-Fixed Tissue of Patients With COVID-19.

OBJECTIVES: The novel coronavirus, severe acute respiratory syndrome coronavirus 2, causing coronavirus disease 2019 (COVID-19) remains a global health threat and a significant source of human morbidity and mortality. While the virus primarily induces lung injury, it also has been reported to cause hepatic sequelae. METHODS: We aimed to detect the virus in formalin-fixed tissue blocks and document the liver injury patterns in patients with COVID-19 compared with a control group. RESULTS: We were able to detect viral RNA in the bronchioalveolar cell blocks (12/12, 100%) and formalin-fixed, paraffin-embedded tissue of the lung (8/8, 100%) and liver (4/9, 44%) of patients with COVID-19. Although the peak values of the main liver enzymes and bilirubin were higher in the patients with COVID-19 compared with the control group, the differences were not significant. The main histologic findings were minimal to focal mild portal tract chronic inflammation (7/8, 88%, P < .05) and mild focal lobular activity (6/8, 75%, P = .06). CONCLUSIONS: We found that most patients who died of COVID-19 had evidence of mild focal hepatitis clinically and histologically; however, the virus was detected in less than half of the cases.

Aberrant expression of TTF1, p63, and cytokeratins in a diffuse large B-cell lymphoma.

Pancytokeratins and TTF-1 are used in working up carcinomas of unknown primary and p63 is expressed in many cell lineages. We present a case of a TTF-1, p63, and cytokeratins positive small round blue cell lesion presenting in a patient with enlarged right supraclavicular lymph nodes and multiple solid pulmonary nodules. The preliminary report to the clinical team was "suspicious for carcinoma." However, after a complete work up the final diagnosis of diffuse large B-cell lymphoma, nongerminal center B-cell phenotype, "double expressor," was rendered (based on Han's algorithm). This case brings up significant diagnostic dilemma as some lymphoid malignancies can morphologically mimic poorly differentiated carcinoma and stain positive for carcinoma markers. Additionally, the frequently used TTF-1 SPT23 antibody clone has strong nuclear staining in rare cases of DLBCL, which is a diagnostic pitfall. To our best knowledge this is the first reported case of DLBCL staining positive for three carcinoma markers.

Malignant melanoma arising in a primary mediastinal germ cell tumor.

Primary mediastinal germ cell tumors with somatic malignancies are rare. We report a case of a 34-year old man with melanoma arising in a primary mediastinal mixed germ cell tumor. On initial biopsy, the patient was found to have a germ cell tumor containing yolk sac and embryonal components only. After chemotherapy, histopathological evaluation of the residual tumor in the wide local resection specimen revealed a mature teratoma with melanoma. Molecular studies demonstrated that the residual germ cell tumor harbored KIT and NRAS mutations associated with malignant melanoma.

Targeting reduced mitochondrial DNA quantity as a therapeutic approach in pediatric high-grade gliomas.

BACKGROUND: Despite increased understanding of the genetic events underlying pediatric high-grade gliomas (pHGGs), therapeutic progress is static, with poor understanding of nongenomic drivers. We therefore investigated the role of alterations in mitochondrial function and developed an effective combination therapy against pHGGs. METHODS: Mitochondrial DNA (mtDNA) copy number was measured in a cohort of 60 pHGGs. The implication of mtDNA alteration in pHGG tumorigenesis was studied and followed by an efficacy investigation using patient-derived cultures and orthotopic xenografts. RESULTS: Average mtDNA content was significantly lower in tumors versus normal brains. Decreasing mtDNA copy number in normal human astrocytes led to a markedly increased tumorigenicity in vivo. Depletion of mtDNA in pHGG cells promoted cell migration and invasion and therapeutic resistance. Shifting glucose metabolism from glycolysis to mitochondrial oxidation with the adenosine monophosphate-activated protein kinase activator AICAR (5-aminoimidazole-4-carboxamide ribonucleotide) or the pyruvate dehydrogenase kinase inhibitor dichloroacetate (DCA) significantly inhibited pHGG viability. Using DCA to shift glucose metabolism to mitochondrial oxidation and then metformin to simultaneously target mitochondrial function disrupted energy homeostasis of tumor cells, increasing DNA damage and apoptosis. The triple combination with radiation therapy, DCA and metformin led to a more potent therapeutic effect in vitro and in vivo. CONCLUSIONS: Our results suggest metabolic alterations as an onco-requisite factor of pHGG tumorigenesis. Targeting reduced mtDNA quantity represents a promising therapeutic strategy for pHGG.

Tau and TDP-43 proteinopathies: kindred pathologic cascades and genetic pleiotropy.

We review the literature on Tau and TDP-43 proteinopathies in aged human brains and the relevant underlying pathogenetic cascades. Complex interacting pathways are implicated in Alzheimer's disease and related dementias (ADRD), wherein multiple proteins tend to misfold in a manner that is "reactive," but, subsequently, each proteinopathy may contribute strongly to the clinical symptoms. Tau proteinopathy exists in brains of individuals across a broad spectrum of primary underlying conditions-e.g., developmental, traumatic, and inflammatory/infectious diseases. TDP-43 proteinopathy is also expressed in a wide range of clinical disorders.  Although TDP-43 proteinopathy was first described in the central nervous system of patients with amyotrophic lateral sclerosis (ALS) and in subtypes of frontotemporal dementia (FTD/FTLD), TDP-43 proteinopathy is also present in chronic traumatic encephalopathy, cognitively impaired persons in advanced age with hippocampal sclerosis, Huntington's disease, and other diseases. We list known Tau and TDP-43 proteinopathies.  There is also evidence of cellular co-localization between Tau and TDP-43 misfolded proteins, suggesting common pathways or protein interactions facilitating misfolding in one protein by the other. Multiple pleiotropic gene variants can alter risk for Tau or TDP-43 pathologies, and certain gene variants (e.g., APOE ε4, Huntingtin triplet repeats) are associated with increases of both Tau and TDP-43 proteinopathies. Studies of genetic risk factors have provided insights into multiple nodes of the pathologic cascades involved in Tau and TDP-43 proteinopathies. Variants from a specific gene can be either a low-penetrant risk factor for a group of diseases, or alternatively, a different variant of the same gene may be a disease-driving allele that is associated with a relatively aggressive and early-onset version of a clinically and pathologically specific disease type. Overall, a complex but enlightening paradigm has emerged, wherein both Tau and TDP-43 proteinopathies are linked to numerous overlapping upstream influences, and both are associated with multiple downstream pathologically- and clinically-defined deleterious effects.

Alzheimer's disease and type 2 diabetes mellitus are distinct diseases with potential overlapping metabolic dysfunction upstream of observed cognitive decline.

Alzheimer's disease (AD) and type 2 diabetes mellitus (T2DM) are highly prevalent aging-related diseases associated with significant morbidity and mortality. Some findings in human and animal models have linked T2DM to AD-type dementia. Despite epidemiological associations between the T2DM and cognitive impairment, the interrelational mechanisms are unclear. The preponderance of evidence in longitudinal studies with autopsy confirmation have indicated that vascular mechanisms, rather than classic AD-type pathologies, underlie the cognitive decline often seen in self-reported T2DM. T2DM is associated with cardiovascular and cerebrovascular disease (CVD), and is associated with increased risk of infarcts and small vessel disease in the brain and other organs. Neuropathological examinations of post-mortem brains demonstrated evidence of cerebrovascular disease and little to no correlation between T2DM and ß-amyloid deposits or neurofibrillary tangles. Nevertheless, the mechanisms upstream of early AD-specific pathology remain obscure. In this regard, there may indeed be overlap between the pathologic mechanisms of T2DM/"metabolic syndrome," and AD. More specifically, cerebral insulin processing, glucose metabolism, mitochondrial function, and/or lipid metabolism could be altered in patients in early AD and directly influence symptomatology and/or neuropathology.

Intraarticular extravasation, an unusual complication of computed tomographic angiography performed with intraosseous needle intravenous access.

Off label use of intraosseous needles (IONs) for contrast media (CM) injection during computed tomographic angiography (CTA) has been reported in small case series and isolated case reports. Presently, complications specific to this novel indication are essentially unknown. In this communication, we report an extravasation of CM from the intramedullary space of the humerus into the glenohumeral joint space during an ION injection of CM during a CTA of the head, neck, and chest. Although clinically insignificant in this case, a more severe intraarticular extravasation could have had both short or long term adverse sequelae. Practitioners of CTA should be aware of this potential complication.

Abducens Nerve Palsy as Initial Presentation of Multiple Myeloma and Intracranial Plasmacytoma.

Central Nervous System (CNS) involvement in multiple myeloma and/or multifocal solitary plasmacytoma is rare. Although they are unique entities, multiple myeloma (MM) and plasmacytoma represent a spectrum of plasma cell neoplastic diseases that can sometimes occur concurrently. Plasmacytomas very often present as late-stage sequelae of MM. In this case report, we report a 53-year-old female presenting with right abducens cranial nerve (CN) VI palsy as an initial presentation secondary to lesion of the right clivus.

Metabolic Alterations in Cancer Cells and the Emerging Role of Oncometabolites as Drivers of Neoplastic Change.

The mitochondrion is an important organelle and provides energy for a plethora of intracellular reactions. Metabolic dysregulation has dire consequences for the cell, and alteration in metabolism has been identified in multiple disease states-cancer being one. Otto Warburg demonstrated that cancer cells, in the presence of oxygen, undergo glycolysis by reprogramming their metabolism-termed "aerobic glycolysis". Alterations in metabolism enable cancer cells to gain a growth advantage by obtaining precursors for macromolecule biosynthesis, such as nucleic acids and lipids. To date, several molecules, termed "oncometabolites", have been identified to be elevated in cancer cells and arise from mutations in nuclear encoded mitochondrial enzymes. Furthermore, there is evidence that oncometabolites can affect mitochondrial dynamics. It is believed that oncometabolites can assist in reprogramming enzymatic pathways and providing cancer cells with selective advantages. In this review, we will touch upon the effects of normal and aberrant mitochondrial metabolism in normal and cancer cells, the advantages of metabolic reprogramming, effects of oncometabolites on metabolism and mitochondrial dynamics and therapies aimed at targeting oncometabolites and metabolic aberrations.