Ferroptosis, Inflammation, and Microbiome Alterations in the Intestine in the Göttingen Minipig Model of Hematopoietic-Acute Radiation Syndrome.

Hematopoietic acute radiation syndrome (H-ARS) involves injury to multiple organ systems following total body irradiation (TBI). Our laboratory demonstrated that captopril, an angiotensin-converting enzyme inhibitor, mitigates H-ARS in Göttingen minipigs, with improved survival and hematopoietic recovery, as well as the suppression of acute inflammation. However, the effects of captopril on the gastrointestinal (GI) system after TBI are not well known. We used a Göttingen minipig H-ARS model to investigate captopril's effects on the GI following TBI (60Co 1.79 or 1.80 Gy, 0.42-0.48 Gy/min), with endpoints at 6 or 35 days. The vehicle or captopril (0.96 mg/kg) was administered orally twice daily for 12 days, starting 4 h post-irradiation. Ilea were harvested for histological, protein, and RNA analyses. TBI increased congestion and mucosa erosion and hemorrhage, which were modulated by captopril. GPX-4 and SLC7A11 were downregulated post-irradiation, consistent with ferroptosis at 6 and 35 days post-irradiation in all groups. Interestingly, p21/waf1 increased at 6 days in vehicle-treated but not captopril-treated animals. An RT-qPCR analysis showed that radiation increased the gene expression of inflammatory cytokines IL1B, TNFA, CCL2, IL18, and CXCL8, and the inflammasome component NLRP3. Captopril suppressed radiation-induced IL1B and TNFA. Rectal microbiome analysis showed that 1 day of captopril treatment with radiation decreased overall diversity, with increased Proteobacteria phyla and Escherichia genera. By 6 days, captopril increased the relative abundance of Enterococcus, previously associated with improved H-ARS survival in mice. Our data suggest that captopril mitigates senescence, some inflammation, and microbiome alterations, but not ferroptosis markers in the intestine following TBI.

Cardiac and Pericardial Neoplasms in Children: Radiologic-Pathologic Correlation.

Primary cardiac and pericardial neoplasms are rare in the pediatric population and can include both benign and malignant lesions. Rhabdomyomas, teratomas, fibromas, and hemangiomas are the most common benign tumors. The most common primary cardiac malignancies are soft-tissue sarcomas, including undifferentiated sarcomas, rhabdomyosarcomas, and fibrosarcomas. However, metastatic lesions are more common than primary cardiac neoplasms. Children with primary cardiac and pericardial tumors may present with nonspecific cardiovascular symptoms, and their clinical presentation may mimic that of more common nonneoplastic cardiac disease. The diagnosis of cardiac tumors has recently been facilitated using noninvasive cardiac imaging. Echocardiography is generally the first-line modality for evaluation. Cardiac MRI and CT are used for tissue characterization and evaluation of tumor size, extension, and physiologic effect. The varied imaging appearances of primary cardiac neoplasms can be explained by their underlying abnormality. Treatment of these lesions varies from conservative management, with spontaneous regression of some lesions such as rhabdomyomas, to surgical resection, particularly in patients with associated heart failure. With adequate imaging techniques and knowledge of the pathologic basis of the neoplasm, it is often possible to differentiate benign from malignant tumors, which can greatly affect adequate and timely treatment. ©RSNA, 2023 Quiz questions for this article are available through the Online Learning Center.

Mediastinal Masses in Children: Radiologic-Pathologic Correlation.

Most pediatric masses in the chest are located in the mediastinum. These masses are often initially detected incidentally on chest radiographs in asymptomatic children, although some patients may present with respiratory symptoms. At chest radiography, the mediastinum has been anatomically divided into anterior, middle, and posterior compartments. However, with the International Thymic Malignancy Interest Group classification scheme, which is based on cross-sectional imaging findings, the mediastinum is divided into prevascular, visceral, and paravertebral compartments. In the prevascular compartment, tumors of thymic origin, lymphomas, germ cell tumors, and vascular tumors are encountered. In the visceral compartment, lymphadenopathy and masses related to the foregut are seen. In the paravertebral compartment, neurogenic tumors are most common. Using the anatomic location in combination with knowledge of the imaging and pathologic features of pediatric mediastinal masses aids in accurate diagnosis of these masses to guide treatment and management decisions. An invited commentary by Lee and Winant is available online. ©RSNA, 2021.

Clinically Unsuspected Injection Drug Abuse in Hospitalized Teens Diagnosed on Pathology.

Intravenous injection of medications intended for oral use can lead to pulmonary hypertension and death. Pathologic findings in the lung include embolization of foreign material, with the specific identification of excipients accomplished through special stains. Risk factors for this type of drug abuse include indwelling venous access and chronic medical problems. These risk factors, especially in adolescent and young adult patients, should prompt intravenous drug use as a possibility of lung disease/lesions. We describe 2 patients from a pediatric hospital with pulmonary pathology indicative of intravenous drug use, identified in autopsy and surgical pathology cases. Drug abuse was not clinically suspected in either patient until the time of pathologic exam, emphasizing a need for the pathologist to be able to recognize the associated histologic changes.

Primary Lung Tumors in Children: Radiologic-Pathologic Correlation From the Radiologic Pathology Archives.

Primary lung tumors in children are rare, with a narrow range of diagnostic considerations. However, the overlapping imaging appearances of these tumors necessitate attention to key discriminating imaging and pathologic features. In the neonate and infant, the important considerations include pleuropulmonary blastoma (PPB), infantile fibrosarcoma, and fetal lung interstitial tumor. Among these tumors, imaging findings such as air-filled cysts in type 1 PPB and homogeneously low attenuation of fetal lung interstitial tumors are relatively specific. Key pathologic and genetic discriminators among this group of tumors include the DICER1 germline mutation found in PPB and the t(12,15)(p13;q25) translocation and ETV6-NTRK3 fusion gene seen in infantile fibrosarcoma. Primary lung tumors in older children include inflammatory myofibroblastic tumors (IMTs), carcinoid salivary gland-type tumors of the lung, recurrent respiratory papillomatosis, and other rare entities. IMT, a spindle-cell proliferation with inflammatory elements, is the most common lung tumor in children. Anaplastic lymphoma kinase, a receptor-type protein tyrosine kinase, is present in 50% of these tumors, and this finding may support an imaging diagnosis of IMT. Carcinoid tumors account for a substantial portion of childhood lung tumors, and their characteristic avid enhancement on images corresponds to the compressed fibrovascular stroma histologically. Furthermore, novel imaging agents used with somatostatin receptor analogs have an emerging role in the evaluation of carcinoid tumors. Although less common than mucoepidermoid carcinoma, adenoid cystic carcinoma tends to recur given the perineural spread seen histologically. Integrating radiologic and pathologic knowledge is critical to accurate diagnosis, treatment planning, and surveillance of primary lung tumors in children.

Rapidly growing subcutaneous mass in an infant.

Fibrous hamartoma of infancy (FHI) is a benign mesenchymal tumor of young children. It has a broad clinical differential diagnosis and is often clinically confused for vascular and malignant soft tissue neoplasms. Recognition of the unique histologic features of FHI, a triphasic population of mature adipose tissue, mature fibrous tissue, and immature mesenchymal tissue, will ensure the correct diagnosis. In this report we present a case of this rare entity, including the associated clinical, radiologic, and histologic findings.

Subcutaneous panniculitis-like T-cell lymphoma in the pediatric age group: a lymphoma of low malignant potential.

BACKGROUND: Subcutaneous panniculitis-like T-cell lymphoma (SPTCL) is a rare neoplasm of mature αß cytotoxic T-cells. Most commonly occurring in young adults, few reports are described in children. A separate analysis of a significant cohort of pediatric patients has not previously been performed. PROCEDURE: We analyzed the pathology including molecular results as well as available clinical data from 16 pediatric patients (age 5 months to 21 years) who had a total of 19 biopsies submitted to the National Cancer Institute from 1999 to 2011. This included 6 males and 10 females. RESULTS: Most patients (10/16, 62.5%) had multiple skin lesions at the time of biopsy. Histologic features included rimming of adipocytes by atypical lymphocytes, fat necrosis, and karyorrhectic debris. Four biopsies showed only partial involvement by lymphoma; and plasma cells were identified in 14/19 (74%) cases, including three in which they were focally prominent. The neoplastic cells in general were positive for CD3, CD8, TIA-1, and ßF1 and were negative for CD4 and CD56. CD5 expression was weak to negative in 5/8 cases (63%). A clonal T-cell receptor gene rearrangement was demonstrated in 11/17 (65%). Patients were treated with a variety of agents. While 5/9 (56%) patients had evidence of recurrent skin lesions, no deaths were attributed to disease for the seven patients with follow-up information. CONCLUSIONS: Pediatric SPTCL shares many clinical and pathologic features with adult SPTCL. The presence of partial involvement or admixed plasma cells makes the differential diagnosis with reactive conditions challenging in some cases.

Pathology Competencies in Medical Education and Educational Cases: Update 2023.

Pathology is a core component of medical school curricula because understanding the pathogenesis of the disease is foundational both for diagnostic efficiency and optimal use of ancillary resources in patient care. The Pathology Competencies for Medical Education (PCME) were developed as a national resource of expectations of pathology knowledge for medical students. The PCME are composed of three competencies: disease mechanisms and processes, organ system pathology, and diagnostic pathology and therapeutic pathology. The learning goals and learning objectives of the PCME that were first published in 2017 have been carefully revised and updated. Significant additions were made to fill gaps of the original PCME objectives, and some learning objectives have been retired or moved to more appropriate locations within the competencies. As curricula and the practice of medicine change, the PCME will continue to be revised and updated periodically. They have and will continue to serve as the organizing principle for the growing number of educational cases published by Academic Pathology. Nomenclature in the original and revised PCME will allow for continued linking of previous and new educational cases to the revised learning objectives. PCME and the educational cases can be adapted into any type of curricula. Having a widely accepted resource of learning objectives in pathology will help students and medical educators focus on essential components of pathology for the future practice of medicine.

Educational Case: Thymoma.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040. 1.

Educational Case: Urinary Stones.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, seehttp://journals.sagepub.com/doi/10.1177/2374289517715040. 1.

Concurrent diagnoses of Hodgkin lymphoma and biclonal myeloma in the bone marrow.

The diagnoses of Hodgkin lymphoma and multiple myeloma have rarely been made simultaneously in the same patient. We present a case of an 82-year-old man who rapidly developed pancytopenia and liver failure with coagulopathy. Serum protein electrophoresis and immunofixation revealed an unequivocal immunoglobulin Gkappa and immunoglobulin Glambda biclonal gammopathy. Bone marrow biopsy showed involvement by classic Hodgkin lymphoma with an inflammatory background including 49% mature plasma cells. Unfortunately, the patient died 14 days after admission. To our knowledge, a case of concurrent Hodgkin lymphoma and biclonal multiple myeloma has not previously been reported. Detection of severe bone marrow plasmacytosis in the background of Hodgkin lymphoma should alert the pathologist to the possibility of collision with a plasma cell neoplasm, warranting a complete diagnostic workup.

Educational Case: Autosomal Dominant Polycystic Kidney Disease.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

Educational Case: Acute Cystitis.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.1.

Cerebellar medulloblastoma in the elderly.

Although medulloblastoma is the most common central nervous system malignancy in children, cases are much less common in adults. Moreover, this tumor is exceedingly rare in patients older than 65 years. Analysis of previous case reports reveals that medulloblastoma in the elderly is more commonly seen in males in a lateral location; histologically, medulloblastomas in aged individuals usually belong to the classic subtype. During intraoperative consultation, the pathologist should consider medulloblastoma in the differential diagnosis of a cerebellar mass in the elderly because cytologic features may overlap with metastatic small cell carcinoma or lymphoma. We present a case of medulloblastoma in a 66-year-old man and review the literature on the subject.

Educational Case: Peripheral Nerve Sheath Tumors.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.

Educational Case: Wilms Tumor.

The following fictional case is intended as a learning tool within the Pathology Competencies for Medical Education (PCME), a set of national standards for teaching pathology. These are divided into three basic competencies: Disease Mechanisms and Processes, Organ System Pathology, and Diagnostic Medicine and Therapeutic Pathology. For additional information, and a full list of learning objectives for all three competencies, see http://journals.sagepub.com/doi/10.1177/2374289517715040.

Increased leukocyte adhesion to vascular endothelium in preeclampsia is inhibited by antioxidants.

OBJECTIVE: To test the hypothesis that plasma from women with preeclampsia increases leukocyte adhesion to vascular endothelial cells and that antioxidants inhibit this effect. STUDY DESIGN: Plasma from 12 women with severe preeclampsia and 12 with normal pregnancy was tested in an in vitro leukocyte-endothelium adhesion assay in the presence or absence of vitamin E, vitamin C, or N-acetylcysteine. RESULTS: Preeclamptic plasma significantly increased monocyte (U937 cells) and T-cell (Jurkat) adhesion to human umbilical vein (HUVEC) and microvascular endothelial cells, compared with normal pregnant plasma. The antioxidants vitamin E, vitamin C, and N-acetylcysteine significantly inhibited monocyte adhesion to HUVEC in the presence of preeclamptic but not normal pregnant plasma. Increased adhesion in response to preeclamptic plasma was not mediated through a protein kinase C (PKC) mechanism, because the PKC inhibitor bisindolylmaleimide I had no effect on adhesion in the presence of preeclamptic plasma. CONCLUSION: Severe preeclampsia is associated with increased leukocyte-endothelium adhesion and clinically useful antioxidants can inhibit this effect.