Testicular Germ Cell Tumors: Serological and Immunohistochemical Diagnosis.

This review deals with serologic and immunohistochemical tumor markers used in clinical laboratories for the diagnosis of testicular germ cell tumors. Time tested serologic markers such as alpha-fetoprotein, human chorionic gonadotropin, and lactate dehydrogenase are routinely used in the work-up of patients with testicular tumors. Professional organizations regulating the practice of medicine in most countries worldwide require that the laboratory values for these serologic reactants be included in the pathology reports on testicular tumors as part of the tumor staging process. Immunohistochemical markers of testicular germ have been identified and widely tested during the first two decades of the XXI century. We have selected the most useful immunohistochemical markers from a few of these markers and discussed them in this review. CONCLUSION: Published data show that testicular tumor markers are widely used in routine practice. The study of tumor markers has improved the pathologic and clinical diagnosis of testicular germ cell tumors and has thus contributed to their treatment.

Right Ventricular Heart Failure from a Cardiac Yolk Sac Tumor.

BACKGROUND Cardiac involvement by a malignant tumor is rare. However, this is a case of right heart failure due to cardiac metastasis from a yolk sac tumor. Although a few case reports of cardiac metastasis from yolk sac tumors have been published, to our knowledge this is the first instance of multiple metastases to the right ventricular of yolk sac tumor in an adult male. CASE REPORT The patient is a 46-year-old male with a history of testicular cancer that presented with dyspnea on exertion. He was found to have two large right sided intracardiac masses on echocardiography. Cardiac magnetic resonance imaging (MRI) was obtained to further investigate these masses. Right ventricular function was decreased and concern for right ventricular outflow tract (RVOT) obstruction was present. The patient was taken to the operating room (OR) for resection of the cardiac masses. Pathology revealed the masses to be yolk sac tumors. Despite urgent resection of the tumors, the patient deteriorated clinically, ultimately succumbing to heart failure. CONCLUSIONS This unique presentation of a yolk sac tumor emphasizes the need to keep a broad differential and complete a thorough workup for any cardiac mass. Early diagnosis and treatment of intra-cardiac masses is imperative due to their high rates of mortality. Albeit an uncommon etiology for heart failure, germ cell tumors can potentially metastasize to the heart and present with such a clinical picture.

High-grade renal cell carcinoma with emperipolesis: Clinicopathological, immunohistochemical and molecular-genetic analysis of 14 cases.

Emperipolesis has recently been described as a constant feature of "biphasic squamoid" papillary renal cell carcinoma (BPRCC). We also noticed this in some high-grade (HG) RCC, which promoted the present study to estimate the incidence of emperipolesis in RCCs and to describe them in further detail. 14 cases of HGRCC showing emperipolesis were retrieved from our registry. Microscopic examination of filed slides was supplemented with immunohistochemical and molecular-genetic analyses using paraffin embedded tissue. 12 of 14 patients were males with a mean age of 58.6 years (range 41-72 years). Tumor size ranged from 6-16.5 cm (mean of 8.8 cm). Follow up data were available for 8/14 patients (range 0.5-10 years). Metastases were documented in 6 cases. All tumors showed solid-alveolar growth patterns with focal pseudopapillary features, and were composed of large cells with bizarre nuclei and eosinophilic rhabdoid-like cytoplasm. Emperipolesis was a constant and prominent feature in large bizarre cells. All cases were positive for OSCAR, CANH 9, vimentin, cyclin D1, INI-1, and myoD1, while negative for melanocytic markers, CK 7, myoglobin, cathepsin K, and TFE3. VHL gene abnormalities were found in 6/9 analyzable cases, of which 2 demonstrated polysomy of chromosomes 7, 17. Emperipolesis is a rare histomorphologic feature which can be seen not only in BPRCCs but also in highgrade CCRCCs. All RCC cases with prominent emperipolesis fulfilled both morphologic and immunohistochemical diagnostic criteria of high-grade CCRCC. The majority of patients with available follow up information developed metastases.

Pluripotent human stem cells: Standing on the shoulders of giants.

The advent of human pluripotent stem cells, with the first derivation of human embryonic stem cells in 1998, and of human induced pluripotent stem cells in 2007, has ushered in an era of considerable excitement about the prospects of using these cells to develop new opportunities for healthcare, from their potential for regenerative medicine to their use as tools for studying the cellular basis of many diseases and the discovery of new drugs. But as with the flowering of many new areas in science, the biology of human pluripotent stem cells has its roots in a long history of, sometimes, less fêted research. In a period when research funding is frequently driven by a desire to meet specific clinical or economic goals, it is salutary to remember that the opportunities offered by human pluripotent stem cells have their origins in curiosity driven research without any of those goals in mind. In this case, that research focused on the relatively rare gonadal cancers known as teratomas, tumors that have fascinated people since antiquity because their sometime grotesque manifestations with haphazard collections of tissues and sometimes recognizable body parts. Although well known to clinical pathologists it was the pioneering work of Leroy Stevens, who first discovered that teratomas occur at a significant rate in the 129 strain of the laboratory mouse and could be produced experimentally, that laid the foundations for our understanding of the biology of these tumors and the central role of the embryonal carcinoma cell, one of the archetypal tumor stem cells.

Teratomas produced from human pluripotent stem cells xenografted into immunodeficient mice - a histopathology atlas.

This atlas illustrates the microscopic features of tumors produced from human pluripotent stem cells (hPSCs) xenografted into immunosuppressed mice, according to the generally accepted protocols for performing this teratoma assay of stem cell pluripotency. Microphotographs depict various hematoxylin and eosin (H&E) stained tissues derived from all three embryonic germ layers (ectoderm, mesoderm and endoderm). The appearance of persistent hPSC in teratomas is also described with special emphasis on the morphogenesis of embryoid bodies and yolk sac components surrounding them. The use of immunohistochemistry for analyzing hPSC-derived teratomas is also illustrated.

Extranodal NK/T Cell Lymphoma Causing Cardiorespiratory Failure.

Extranodal NK/T cell lymphoma is an uncommon malignancy usually involving the sinonasal area. We report an unusual case of extranodal NK/T cell lymphoma diagnosed in a 62-year-old Caucasian male who died of progressive cardiorespiratory failure but had no clinically detectable upper respiratory system lesions. The initial diagnosis was made cytologically on a sample of pericardial fluid that contained neoplastic lymphoid cells. These cells were positive for CD2, cytoplasmic CD3, and Epstein-Barr virus and negative for CD56. The diagnosis was confirmed at the autopsy, which disclosed lymphoma infiltrates in the myocardium, lungs, stomach, and pancreas. The death was caused by heart and lung failure due to uncontrollable arrhythmia and respiratory insufficiency due to the lymphoma infiltrates. To the best of our knowledge, this is the first case of extranodal NK/T cell lymphoma presenting with cardiopulmonary failure.

Littoral cell angioma of the spleen: a study of 25 cases with confirmation of frequent association with visceral malignancies.

AIMS: Littoral cell angioma (LCA) is a rare primary splenic tumour that is frequently associated with internal malignancies. Immunohistochemistry can demonstrate a distinct hybrid endothelial-histiocytic phenotype of littoral cells, and is a helpful adjunct for making the correct diagnosis. The aims of this study were to present a series of 25 LCAs, with an emphasis on the frequent association of the neoplasm with visceral malignancies, and to provide a detailed immunohistochemical analysis by employing new markers. METHODS AND RESULTS: All 25 cases with available tissue blocks were immunohistochemically stained for endothelial and histiocytic markers. Clinical and follow-up data were retrieved from the respective institutions. The tumours were obtained from 16 males and nine females, whose age ranged from 32 to 86 years (mean 56.2 years). Clinical information was available for 24 of 25 patients, and follow-up for 11 of 25 patients (range 2-19 years; mean 11.6 years). Immunohistochemically, all cases were positive for LYVE-1, factor VIII, FLI-1, vascular endothelial growth factor receptor (VEGFR)-2, VEGFR-3, claudin-5, ERG, LMO2, CD31, CD163, lysozyme, and CD4, but negative for D2-40, CD8, and factor XIIIa. Fifteen of 25 cases were associated with various malignancies, including epithelial, mesenchymal and haematological tumours. CONCLUSIONS: The cohort of 25 patients is the largest series of LCAs published to date. By using antibodies against recently introduced endothelial markers, we have expanded the immunoprofile of LCA. We have further highlighted the clinical significance of LCA, as more than half of the patients in this study also harboured a coexisting visceral malignancy. Therefore, we conclude that the finding of splenic LCA mandates a thorough clinical evaluation for a concomitant malignancy.

Mammary Analogue Secretory Carcinoma (MASC) of the salivary gland: A new tumor entity.

Mammary analogue secretory carcinoma (MASC) is a recently described low-grade malignant tumor of the salivary glands, biologically and morphologically equivalent to secretory breast carcinoma. We give a brief overview of this new entity, including morphological, immunohistochemical, molecular-genetic, clinical, epidemiologic features, differential diagnosis, and outcome results.

Biphasic Squamoid Alveolar Renal Cell Carcinoma: A Distinctive Subtype of Papillary Renal Cell Carcinoma?

Biphasic squamoid alveolar renal cell carcinoma (BSARCC) has been recently described as a distinct neoplasm. Twenty-one cases from 12 institutions were analyzed using routine histology, immunohistochemistry, array comparative genomic hybridization (aCGH) and fluorescence in situ hybridization. Tumors were removed from 11 male and 10 female patients, whose age ranged from 53 to 79 years. The size of tumors ranged from 1.5 to 16 cm. Follow-up information was available for 14 patients (range, 1 to 96 mo), and metastatic spread was found in 5 cases. All tumors comprised 2 cell populations arranged in organoid structures: small, low-grade neoplastic cells with scant cytoplasm usually lining the inside of alveolar structures, and larger squamoid cells with more prominent cytoplasm and larger vesicular nuclei arranged in compact nests. In 9/21 tumors there was a visible transition from such solid and alveolar areas into papillary components. Areas composed of large squamoid cells comprised 10% to 80% of total tumor volume. Emperipolesis was present in all (21/21) tumors. Immunohistochemically, all cases were positive for cytokeratin 7, EMA, vimentin, and cyclin D1. aCGH (confirmed by fluorescence in situ hybridization) in 5 analyzable cases revealed multiple numerical chromosomal changes including gains of chromosomes 7 and 17 in all cases. These changes were further disclosed in 6 additional cases, which were unsuitable for aCGH. We conclude that tumors show a morphologic spectrum ranging from RCC with papillary architecture and large squamoid cells to fully developed BSARCC. Emperipolesis in squamoid cells was a constant finding. All BSARCCs expressed CK7, EMA, vimentin, and cyclin D1. Antibody to cyclin D1 showed a unique and previously not recognized pattern of immunohistochemical staining. Multiple chromosomal aberrations were identified in all analyzable cases including gains of chromosomes 7 and 17, indicating that they are akin to papillary RCC. Some BSARCCs were clinically aggressive, but their prognosis could not be predicted from currently available data. Present microscopic, immunohistochemical, and molecular genetic data strongly support the view that BSARCC is a distinctive and peculiar morphologic variant of papillary RCC.

Apoptosis and failure of checkpoint kinase 1 activation in human induced pluripotent stem cells under replication stress.

BACKGROUND: Human induced pluripotent stem (hiPS) cells have the ability to undergo self-renewal and differentiation similarly to human embryonic stem (hES) cells. We have recently shown that hES cells under replication stress fail to activate checkpoint kinase 1 (CHK1). They instead commit to apoptosis, which appears to be a primary defense mechanism against genomic instability. It is not known whether the failure of CHK1 activation and activation of apoptosis under replication stress is solely a feature of hES cells, or if it is a feature that can be extended to hiPS cells. METHODS: Here we generated integration-free hiPS cell lines by mRNA transfection, and characterised the cell lines. To investigate the mechanism of S phase checkpoint activation, we have induced replication stress by adding excess thymidine to the cell culture medium, and performed DNA content analysis, apoptosis assays and immunoblottings. RESULTS: We are showing that hiPS cells similarly to hES cells, fail to activate CHK1 when exposed to DNA replication inhibitors and commit to apoptosis instead. Our findings also suggest the Ataxia Telangiectasia Mutated pathway might be responding to DNA replication stress, resulting in apoptosis. CONCLUSION: Together, these data suggest that the apoptotic response was properly restored during reprogramming with mRNA, and that apoptosis is an important mechanism shared by hiPS and hES cells to maintain their genomic integrity when a replication stress occurs.

Do glucagonomas always produce glucagon?

Pancreatic islet α-cell tumours that overexpress proglucagon are typically associated with the glucagonoma syndrome, a rare disease entity characterised by necrolytic migratory erythema, impaired glucose tolerance, thromboembolic complications and psychiatric disturbances. Paraneoplastic phenomena associated with enteric overexpression of proglucagon-derived peptides are less well recognized and include gastrointestinal dysfunction and hyperinsulinaemic hypoglycaemia. The diverse clinical manifestations associated with glucagon-expressing tumours can be explained, in part, by the repertoire of tumorally secreted peptides liberated through differential post-translational processing of tumour-derived proglucagon. Proglucagon-expressing tumours may be divided into two broad biochemical subtypes defined by either secretion of glucagon or GLP-1, GLP-2 and the glucagon-containing peptides, glicentin and oxyntomodulin, due to an islet α-cell or enteroendocrine L-cell pattern of proglucagon processing, respectively. In the current review we provide an updated overview of the clinical presentation of proglucagon-expressing tumours in relation to known physiological actions of proglucagon-derived peptides and suggest that detailed biochemical characterisation of the peptide repertoire secreted from these tumours may provide new opportunities for diagnosis and clinical management.

Does everything a surgeon takes out have to be seen by a pathologist? A review of the current pathology practice.

Histopathologic examination of surgically removed tissues and organs is an important aspect of modern hospital quality health care. Most surgical specimens deserve to be submitted for pathologic examination, which may yield valuable new information relevant for the future treatment of the patient. A small number of specimens, recognized as providing limited or no valuable clinical data during pathologic examination, may be placed on the list of specimens "exempt from submission" or those that are labeled as "for gross examination only." Guidelines written by the committees of the national regulatory organizations provide general orientation on how to deal with various specimens, but the final decision on which type of specimen to eliminate and which ones to include for pathologic examination rests on local governing and advisory bodies of each institution. Particular lists of specimens exempt from pathologic examination are best generated through a consensus agreement of clinical and laboratory physicians. Even though there is general nationwide and even international consensus on which types of specimens deserve pathologic examination and which do not, there are still discussions about the necessity of some pathologic examinations.

Polyomavirus nephropathy of the native kidney in a patient with rheumatoid arthritis and pulmonary fibrosis.

Polyomavirus nephropathy is commonly seen in the renal allograft setting but is uncommon in native kidneys. This paper describes polyomavirus nephropathy that developed in the native kidneys of a patient following immunosuppressive therapy for rheumatoid arthritis/Sjögren's syndrome associated lung disease. The patient presented with dyspnoea and a slow steady rise in serum creatinine. Owing to chronic immunosuppression, calcineurin-inhibitor toxicity was suspected. However, renal biopsy revealed polyomavirus nephropathy. The treatment of choice, lowered immunosuppression, was complicated by exacerbation of the patient's lung disease. This case highlights features of polyomavirus nephropathy in the native kidney, as well as the difficulty in its treatment when immunosuppressive treatment is necessary for medical comorbidities.

Regulated cell death in diagnostic histopathology.

Regulated cell death (RCD) is a controlled cellular process, essential for normal development, tissue integrity and homeostasis, and its dysregulation has been implicated in the pathogenesis of various conditions including developmental and immunological disorders, neurodegenerative diseases, and cancer. In this review, we briefly discuss the historical perspective and conceptual development of RCD, we overview recent classifications and some of the key players in RCD; finally we focus on current applications of RCD in diagnostic histopathology.

Development of Teratocarcinomas and Teratomas in Severely Immunodeficient NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl)/Szj (NSG) Mice.

The embryonic portion of 7-day-old mouse embryos transplanted to extrauterine sites of syngeneic adult animals gives rise to teratoid tumors, which may be either benign [teratomas (T)] or malignant [teratocarcinomas (TC)]. The incidence of embryo-derived TC varies from one mouse strain to another, indicating that some strains are TC-permissive whereas others are relatively TC-nonpermissive. Embryos of a TC-permissive mouse strain (DBA/2J) and a TC-nonpermissive one (C57BL/6J) were transplanted into NOD.Cg-Prkdc(scid) Il2rg(tm1Wjl)/SzJ (NSG) mice to determine their tumorigenic potential in the absence of functional adaptive and innate immune responses in the hosts. C57BL/6J embryos transplanted to NSG mice gave rise to TC in 31% of cases, whereas the incidence of TC produced from DBA/2J transplanted embryos was 71%. The NSG embryos transplanted to syngeneic hosts gave rise to TC in 67% of cases, allowing the classification of NSG as a TC-permissive strain. A previously reported correlation between teratocarcinoma and splenomegaly was also observed in the NSG mice. The capacity of these tumors to differentiate into the cells and tissues of the normal embryo is mapped through a detailed histological analysis. These data suggest that teratocarcinogenesis, in the absence of host innate and adaptive immunity, is largely determined by the genetic background of the embryo.

Decidua and implantation of the embryo from a historical perspective.

Implantation of the embryo is critical for the initiation of intrauterine development of early embryos. It depends on the proper soil formed by the decidualized pregnant uterus. In the present article I have reviewed the evolution of the modern concepts of decidualization and embryonic implantation, emphasizing how closely interrelated these two processes are. Special emphasis and recognition is given to the Boston pathologist Arthur T. Hertig, who studied for 15 years with another Bostonian, John Rock, a gynecologist, human implantation and early embryogenesis, thus providing the basis for future studies of human reproductive biology, infertility and contraception.