Histopathologic, phenotypic, and molecular criteria to discriminate low-grade intestinal T-cell lymphoma in cats from lymphoplasmacytic enteritis

BACKGROUND

Differentiation of low-grade intestinal T-cell lymphoma (LGITL) from lymphoplasmacytic enteritis (LPE) in cats is a diagnostic challenge for pathologists.

OBJECTIVE

Characterize histologic, immunohistochemical, and molecular features of LGITL and LPE.

ANIMALS

Forty-four client-owned cats, 22 diagnosed with LGITL and 22 with LPE.

METHODS

Prospective, cohort study. Clinical suspicion of LGITL or LPE was based on persistent gastrointestinal signs, unresponsive to empirical treatments. All cats underwent a standardized diagnostic evaluation, including biopsy (preferentially full-thickness), and were diagnosed with LGITL or LPE after review of clinical, laboratory, sonographic, histologic, immunohistochemical, and clonality results.

RESULTS

A monomorphic lymphocytic population (22/22, 100%) and in-depth mucosal infiltration (15/22, 68%) were hallmarks of LGITL. Epithelial patterns (nests and plaques) were significantly more frequent in LGITL (11/22, 50%) than in LPE (1/22, 5%) cases (P = .001). A CD3+ lymphocytic apical-to-basal gradient was observed in 9/22 (41%) of LGITL vs 1/22 (5%) of LPE cases (P = .004). Most LPE cases (17/18, 94%) featured marked fibrosis in the superficial part of the lamina propria. The Ki-67 20%- and 30%-thresholds discriminated between LGITL and LPE within both the epithelium (specificity >95%) and lamina propria (specificity >95%), respectively. All LGITL cases were CD3+ pSTAT3- and pSTAT5+. T-cell receptor gamma chain gene rearrangements indicated monoclonality in 86% of LGITL cases. Surprisingly, 70% of LPE cases featured monoclonality (40%) or monoclonality on a polyclonal background (30%).

CONCLUSIONS AND CLINICAL IMPORTANCE

We identified new histologic, immunohistochemical, and clonality criteria to distinguish LGITL from LPE.

Protein expression of angiotensin-converting enzyme 2, a SARS-CoV-2-specific receptor, in fetal and placental tissues throughout gestation: new insight for perinatal counseling

OBJECTIVE

Pregnant women can be infected by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), yet the incidence of perinatal infection is low. We hypothesized that this could be related to low expression of the membrane receptor for SARS-CoV-2, angiotensin-converting enzyme 2 (ACE2), in the fetoplacental unit. We evaluated protein expression of ACE2 at various gestational ages in both placentae and fetal organs from pregnancies not infected with SARS-CoV-2.

METHODS

In May 2020, using samples from a registered biobank, we performed immunohistochemical analysis for ACE2 in tissue samples from fetal organs and placentae from five cases of second- or third-trimester medical termination of pregnancy in healthy women (performed between 15 and 38 weeks' gestation), as well as a further two placentae, one from a 7-week spontaneous miscarriage in a non-infected woman and one from a symptomatic pregnant woman positive for SARS-CoV-2 delivered by Cesarean section at 34 weeks. Samples were paraffin-embedded and organ tissues included kidney, brain, lung, intestinal tract, heart and testis. Matching tissues (kidney, intestinal tract, lung and testis) from autopsies of four 8-year-old children were tested as controls. Tissue sections were incubated with rabbit monoclonal anti-ACE2, and protein expression of ACE2 was detected by immunohistochemistry.

RESULTS

ACE2 expression was detected in fetal kidney, rectum and ileum samples from 15 weeks onwards and in the pediatric controls. It was barely detectable in fetal lung samples at 15 + 5 weeks' gestation and not detectable thereafter, and, in the pediatric controls, ACE2 was detectable only in type-2 pneumocytes. No ACE2 expression was found in the cerebral ependymal or parenchymal tissues or in cardiac tissues. ACE2 was expressed in placental syncytiotrophoblast and cytotrophoblast samples, but not in the amnion, from 7 weeks onwards. The intensity and distribution of ACE2 staining in the placenta from the symptomatic SARS-CoV-2 woman was similar to that in the non-infected placentae.

CONCLUSIONS

Marked placental expression of ACE2 provides a rationale for vertical transmission at the cellular level. Absence of ACE2 expression in the fetal brain and heart is reassuring regarding the risk of congenital malformation. Clinical follow-up of infected pregnant women and their children is needed to validate these observations. © 2020 International Society of Ultrasound in Obstetrics and Gynecology.

Penetration and decontamination of americium-241 ex vivo using fresh and frozen pig skin

Skin contamination is one of the most probable risks following major nuclear or radiological incidents. However, accidents involving skin contamination with radionuclides may occur in the nuclear industry, in research laboratories and in nuclear medicine departments. This work aims to measure the penetration of the radiological contaminant Americium (²⁴¹Am) in fresh and frozen skin and to evaluate the distribution of the contamination in the skin. Decontamination tests were performed using water, Fuller's earth and diethylene triamine pentaacetic acid (DTPA), which is the recommended treatment in case of skin contamination with actinides such as plutonium or americium. To assess these parameters, we used the Franz cell diffusion system with full-thickness skin obtained from pigs' ears, representative of human skin. Solutions of ²⁴¹Am were deposited on the skin samples. The radioactivity content in each compartment and skin layers was measured after 24 h by liquid scintillation counting and alpha spectrophotometry. The Am cutaneous penetration to the receiver compartment is almost negligible in fresh and frozen skin. Multiple washings with water and DTPA recovered about 90% of the initial activity. The rest remains fixed mainly in the stratum corneum. Traces of activity were detected within the epidermis and dermis which is fixed and not accessible to the decontamination.

Prototype of Kepler Processing Workflows For Microscopy And Neuroinformatics

We report on progress of employing the Kepler workflow engine to prototype “end-to-end” application integration workflows that concern data coming from microscopes deployed at the National Center for Microscopy Imaging Research (NCMIR). This system is built upon the mature code base of the Cell Centered Database (CCDB) and integrated rule-oriented data system (IRODS) for distributed storage. It provides integration with external projects such as the Whole Brain Catalog (WBC) and Neuroscience Information Framework (NIF), which benefit from NCMIR data. We also report on specific workflows which spawn from main workflows and perform data fusion and orchestration of Web services specific for the NIF project. This “Brain data flow” presents a user with categorized information about sources that have information on various brain regions.

The OptIPuter microscopy demonstrator: enabling science through a transatlantic lightpath

The OptIPuter microscopy demonstrator project has been designed to enable concurrent and remote usage of world-class electron microscopes located in Oxford and San Diego. The project has constructed a network consisting of microscopes and computational and data resources that are all connected by a dedicated network infrastructure using the UK Lightpath and US Starlight systems. Key science drivers include examples from both materials and biological science. The resulting system is now a permanent link between the Oxford and San Diego microscopy centres. This will form the basis of further projects between the sites and expansion of the types of systems that can be remotely controlled, including optical, as well as electron, microscopy. Other improvements will include the updating of the Microsoft cluster software to the high performance computing (HPC) server 2008, which includes the HPC basic profile implementation that will enable the development of interoperable clients.

[Quality of interaction database management systems]

OBJECTIVE

To identify drug interaction databases (DID) and assess the quality of their structures.

METHOD

A search was made of the literature for DID and a series of exclusion and structural quality criteria were defined (at least four quality criteria: Classification according to severity, classification according to level of evidence, bibliographical reference data, description of clinical management and 11 criteria used for weighting). The level of compliance of every DID with the criteria defined was analysed, together with the level of compliance of each criteria in each DID.

RESULTS

A total of 54 DID were identified, 30 of which complied with exclusion criteria and 15 of which did not meet the minimum criteria. The rest of the criteria were evaluated in nine DID: Bot-plus and Medinteract (100 %), SEFH Guide, Lexi-interact and Medscape (89 %), Hansten (83 %), Micromedex and Stockley (78 %), Drug Interactions Facts (68 %). Ninety-two per cent of the DID describe the mechanism of action, 87 % classify the information according to the active ingredient, 75 % do not state they have any conflict of interest, classify according to level of severity, have electronic format and are easy to search. A total of 67 % are specific DID, 62 % are classified according to level of evidence, contain bibliographical references and describe clinical management.

CONCLUSIONS

A third of the DID comply with the minimum criteria. Differences were observed in the level and compliance criteria among Spanish and foreign DID. Some of the main DID used as references in the bibliography have significant structural defects: no web presentation, no multi-check function and others.

Quality of interaction database management systems

Objective

To identify drug interaction databases (DID) and assess the quality of their structures.

Method

A search was made of the literature for DID and a series of exclusion and structural quality criteria were defined (at least 4 quality criteria: classification according to severity, classification according to level of evidence, bibliographical reference data, description of clinical management, and 11 criteria used for weighting). The level of compliance of every DID with the criteria defined was analysed, together with the level of compliance of each criteria in each DID.

Results

A total of 54 DID were identified, 30 of which complied with exclusion criteria and 15 of which did not meet the minimum criteria. The rest of the criteria were evaluated in 9 DID: Botplus and Medinteract (100%), SEFH Guide, Lexi-interact and Medscape (89%), Hansten (83%), Micromedex and Stockley (78%), Drug Interactions Facts (68%). Ninety-two percent of the DID describe the mechanism of action, 87% classify the information according to the active ingredient, 75% do not state they have any conflict of interest, classify according to level of severity, have electronic format, and are easy to search. A total of 67% are specific DID, 62% are classified according to level of evidence, contain bibliographical references, and describe clinical management.

Conclusions

A third of the DID comply with the minimum criteria. Differences were observed in the level and compliance criteria among Spanish and foreign DID. Some of the main DID used as references in the bibliography have significant structural defects: no web presentation, no multi-check function and others.

Marginal zone lymphoma of both spleen and kidney displaying transformation into large B-cell lymphoma

We report a case of simultaneous involvement of the spleen and the left kidney in a marginal zone lymphoma with a monotypic lymphoplasmacytic cell component, which transformed into a diffuse large B-cell lymphoma of the immunoblastic type. PCR showed that the small and large B-cell populations carried the same type of immunoglobulin heavy chain gene rearrangement. This type of rearrangement was detected in the spleen, the latero-aortic lymphadenopathy and the kidney demonstrating that it is the same lymphoma that affected both organs and the lymph nodes. Primary renal lymphoma is very rare and only a few cases of renal marginal zone lymphoma, MALT type, have been reported. Involvement of simultaneous multiple sites has been described in MALT type lymphoma, but splenic involvement secondary to renal MALT lymphoma seems to have never been observed. Nevertheless, in our case the huge size of the spleen associated with splenic hilar node involvement is consistent with primary splenic marginal zone lymphoma. The extension into latero-aortic lymph nodes of this lymphoma can explain secondary kidney involvement. The nodal Kaposi's sarcoma observed in this patient of Mediterranean origin was probably coincidental.

Initial lesions of classical Hodgkin's lymphoma of the nodular sclerosis type

The necessity of correct diagnostics of initial lesions of Hodgkin's lymphoma is underlined. The correct assessment may relate of more than 90% of such observation to 90% of noduler sclerosis. The criteria similar to those of WHO are suggested for the differentiation with mixed-cell or lymphoid preponderance.

[MALT (Mucosal Associated Lymphoid Tissue) lymphoma of the palpebral conjunctiva]

BACKGROUND

MALT (Mucosal Associated Lymphoid Tissue) lymphomas of the conjunctiva belong to the extranodal marginal zone B-cell lymphomas. This site, while standard, is uncommon.

CASE-REPORT

A pink papular tumor developed on the lower eyelid of a 59-year-old woman. Sarcoidosis was diagnosed 9 years earlier associated with mediastinal lymphadenopathy and erythema nodosum not requiring treatment. Histological examination yielded a diagnosis of conjunctival MALT lymphoma. No visceral involvement was demonstrated. Radiotherapy (30 Gy) induced a complete response. A remote lesion developed on the patient's arm 18 months later. No other sites were found. Further radiotherapy (26 Gy) again induced complete remission. No new lesions were seen after 24 months of follow-up.

DISCUSSION

This case is interesting because of the association of a MALT lymphoma and previous sarcoidosis, described in the literature as "sarcoidosis-lymphoma syndrome". Association of sarcoidosis with MALT lymphoma is infrequent. Treatment of conjunctival MALT lymphoma is standardized. Radiotherapy offers excellent efficacy and is well tolerated at this site. Regular and long-term follow-up is required. Local and distant relapse can occur.

Résultats de la TEP [18F]-FDG dans la stadification préopératoire des tumeurs pulmonaires

BACKGROUND

Positron emission tomography (PET) with [18F]fluorodeoxyglucose (FDG) has recently established itself as an important imaging strategy in the management of respectable non-small cell bronchial carcinoma (NSCLC). In this study we report our experience of the impact of FDG-PET in the pre-operative assessment of NSCLC.

METHODS

In a single centre retrospective study between 01 January 2000 and 31 Dec 2002, 108 FDGPET scans were performed during the preoperative assessment of histologically proven or strongly suspected NSCLC.

RESULTS

The sensitivity, specificity and accuracy of FDG-PET for the characterization of a parenchymatous opacity were 96%, 71% and 92% respectively (4 false negatives, 5 false positives). The sensitivity, specificity and accuracy for mediastinal node involvement were 62%, 94% and 84% respectively (10 false negatives and 4 false positives). The sensitivity, specificity and accuracy for the characterization of adrenal nodules were 88%, 100% and 97% (1 false negative) and for satellite pulmonary nodules 50%, 75% and 64% (2 false negatives and 3 false positives).

CONCLUSION

FDG-PET is a useful imaging modality in the pre-operative management of NSCLC but is limited particularly in the characterization of lesions less than 10 mm in diameter and in the evaluation of mediastinal lymph nodes.

[Plasma cell leukaemia]

We report a case of primary plasma cell leukaemia, with an absolute count of plasma cells of 53 Giga/L, diagnosed in a 83-year-old woman. The patient's condition improved, with no circulating plasma cells after 3 weeks of treatment, in response to the combination of thalidomide and dexamethasone administered for 5 days followed by thalidomide alone. The clinical presentation, the morphological, flow cytometric and pathophysiological characteristics of the plasma cell leukaemia and the treatment are summarised in this paper.

Incidence and risk factors for central nervous system occurrence in elderly patients with diffuse large-B-cell lymphoma: influence of rituximab

BACKGROUND

The incidence of secondary central nervous system (CNS) occurrences in diffuse large-B-cell lymphoma is not sufficiently high to warrant the use of CNS prophylaxis in all patients. The addition of rituximab increases the complete response rate and prolongs event-free and overall survival in elderly patients with such lymphoma.

PATIENTS AND METHODS

We analyzed a cohort of 399 elderly patients with lymphoma prospectively treated with eight cycles of CHOP with or without rituximab in order to assess if rituximab decreases the risk of CNS localization. Prophylaxis of CNS disease was not part of the treatment protocol.

RESULTS

We observed 20 CNS occurrences: 12 on therapy, four after partial remission and four following complete remission. In three patients, the CNS was the only site of relapse. In a multivariate analysis, increased age-adjusted International Prognostic Index (IPI) was the only independent predictive factor of CNS recurrence. Only three of 20 patients are alive with a follow-up of 24 months.

CONCLUSIONS

Rituximab did not influence the risk of CNS occurrence, possibly because of low rituximab diffusion. Direct intrathecal administration of rituximab could overcome this problem. We also confirmed that CNS occurrence is related to IPI as well as very poor prognosis of relapses occurring on therapy.

Myeloid sarcoma: clinical and morphologic criteria useful for diagnosis

Extramedullary accumulation of myeloblasts or immature myeloid cells form tumors called myeloid sarcoma in the WHO classification. Such tumors develop in lymphoid organs, bone (skull, orbit, etc.), skin, soft tissue, various mucosae and organs, and the CNS. They may precede or occur concurrently with acute myeloid leukemia, or reveal blastic transformation of chronic myeloproliferative disorders or myelodysplastic syndromes. They may also reveal relapses in treated patients. They are constituted by a diffuse infiltrate made up of medium-to-large cells. The cells are difficult to identify. Imprints are very useful. Immunohistochemistry can help diagnose and distinguish four variants: granulocytic myeloperoxidase (MPO+, CD 68+ [KP1+/-, PGM1-] lysozyme+, CD 34+/-), monoblastic (MPO-, CD 68+, [KP1+, PGM1+] lysozyme+, CD 34-), myelomonoblastic (MPO-, CD 68+, [KP1+, PGM1+] lysozyme+, CD 34-), or megakaryoblastic (positivity for factor VIII, CD 61, CD 31). Immunohistochemistry sometimes demonstrates expression of CD 43, CD 7, CD 79a, and CD 56 (particularly the monoblastic variant with t[8;21]). Recently the demonstration of CD 99 and CD 117, which can now be done on paraffin sections, may be useful to identify blasts of granulocytic origin. The diagnosis is missed in about 50% of cases when immunohistochemistry is not used. Patients with myeloid sarcomas should be treated in the same way as patients with acute myeloblastic leukemia. Disease progression and prognosis are similar for the two conditions.

Primary histiocytic sarcoma of the spleen associated with erythrophagocytic histiocytosis

We report an exceptional case of a histiocytic sarcoma presenting as a primary isolated spleen tumor in a 71-year-old woman. The neoplastic cells in the cords and sinuses of the red pulp formed multiple lobulated tumors, which were detected in vivo by ultrasound scan. The medium cells, large cells and the giant cells expressed CD68, a histiocyte-associated marker, lysozyme and S100 protein. All these cells were negative for B- and T-cell markers, cytokeratins, melanosome markers (HMB45) and CD1a (Langerhans' cells). Many tumor cells displayed strong erythrophagocytosis and sometimes lymphocytophagocytosis. In addition, numerous histiocytes with morphology indistinguishable from reactive macrophages also exhibited a strong erythrophagocytosis, and were found in the tumor as well as in the normal splenic parenchyma. Despite multi-agent chemotherapy, the patient suffered from a relapse in the liver, with a rapid fatal outcome. A literature review showed that such a primary splenic presentation with multiple tumors is rare. In contrast, in systemic malignant histiocytosis, secondary spleen involvement occurs more frequently but with diffuse infiltration. The association with a reactive histiocytosis with erythrophagocytosis corresponds to "histiocytic medullary reticulosis", as previously described by Scott and Robb-Smith.