[Clinical procedures for intraocular lymphomas]

BACKGROUND

The classification of intraocular lymphomas is based on their anatomical location. They are divided into uveal lymphomas with involvement of the choroid, ciliary body or iris and vitreoretinal lymphomas with isolated or combined involvement of the vitreous body and/or retina. Over the last decades it has become increasingly possible to work out the clinical and pathobiological features of the various subtypes, thereby reducing the diagnostic hurdles and creating improved treatment options.

OBJECTIVE

A summary of the various types of intraocular lymphoma in terms of clinical features, diagnostics, treatment and prognosis is given as well as recommendations for follow-up care.

METHODS

A selective literature search was carried out on the subject of intraocular lymphomas using PubMed and Google Scholar.

RESULTS

Intraocular lymphomas affect different structures, so that the symptoms can also be very different. The diagnostic spectrum ranges from typical ocular examination methods to sample biopsies with subsequent cytological, histological and molecular pathological processing. The treatment pillars available are percutaneous irradiation and intravitreal drug administration as local treatment and systemic treatment or a combination of systemic and local treatment. The prognosis depends mainly on the subtype of the lymphoma and the extent of the infestation when the diagnosis is confirmed. Even though some effective treatment options are now available, it has not yet been possible to significantly reduce the mortality rate.

CONCLUSION

Many different options are available for the diagnostics and treatment of intraocular lymphomas, which require close interdisciplinary cooperation. The further developments in the field of molecular pathology allow a faster and more accurate diagnosis and could open up new treatment options in the future.

[Update on collaborative autopsy-based research in German pathology, neuropathology, and forensic medicine]

BACKGROUND

Autopsies are a valuable tool for understanding disease, including COVID-19.

MATERIALS AND METHODS

The German Registry of COVID-19 Autopsies (DeRegCOVID), established in April 2020, serves as the electronic backbone of the National Autopsy Network (NATON), launched in early 2022 following DEFEAT PANDEMIcs.

RESULTS

The NATON consortium's interconnected, collaborative autopsy research is enabled by an unprecedented collaboration of 138 individuals at more than 35 German university and non-university autopsy centers through which pathology, neuropathology, and forensic medicine autopsy data including data on biomaterials are collected in DeRegCOVID and tissue-based research and methods development are conducted. More than 145 publications have now emerged from participating autopsy centers, highlighting various basic science and clinical aspects of COVID-19, such as thromboembolic events, organ tropism, SARS-CoV‑2 detection methods, and infectivity of SARS-CoV-2 at autopsy.

CONCLUSIONS

Participating centers have demonstrated the high value of autopsy and autopsy-derived data and biomaterials to modern medicine. The planned long-term continuation and further development of the registry and network, as well as the open and participatory design, will allow the involvement of all interested partners.

[Genetic evolution of in situ follicular neoplasia to t(14;18)-positive aggressive B-cell lymphoma]

BACKGROUND

In situ follicular neoplasia (ISFN) is a t(14;18)(q32;q21)⁺ precursor lesion of follicular lymphoma (FL), which in turn can transform into diffuse large B‑cell lymphoma (DLBCL). For DLBCL that arise de novo, no precursor lesion is known. Given the high frequency of the t(14;18) translocation in de novo DLBCL as well, we investigated whether they can also arise from ISFN without FL as an intermediate step.

OBJECTIVES

To investigate the clonal evolution of ISFN to DLBCL - transformed from FL and de novo.

MATERIALS AND METHODS

Identification of ISFN lesions in patients with DLBCL was performed by BCL2 staining of reactive lymphoid tissues. ISFN and DLBCL were subsequently analyzed by fluorescence in situ hybridization, clonality analyses, sequencing of the t(14;18) breakpoint, and targeted next-generation sequencing.

RESULTS

10 cases with paired ISFN and DLBCL samples were identified, 6 of which were de novo DLBCL and 4 transformed from FL. 3 DLBCL carried MYC-rearrangements in addition to the t(14;18) and were classified as high-grade B‑cell lymphoma (HGBL). The clonal relationship of ISFN and DLBCL/HGBL was confirmed for all cases. CREBBP, KMT2D, EZH2, TNFRSF14, and BCL2 were the genes most frequently mutated, with the distribution of private and shared mutations pointing to 2 different scenarios of clonal evolution. In most cases, DLBCL/HGBL, ISFN, and, if also present, FL had evolved divergently from a common progenitor, whereas linear evolution was less frequent.

CONCLUSION

We show for the first time that t(14;18)⁺ DLBCL/HGBL can arise directly from ISFN without FL as an intermediate step and that during this progression, divergent evolution is common.

[Organoids for the advancement of intraoperative diagnostic procedures]

In the context of cancer surgery, there is always a trade-off between oncological safety and preservation of function. This is especially true in pelvic surgery due to the close relationship to the pelvic floor muscles, blood supply and nerves. Currently, risk models, preoperative imaging, the surgeon's assessment, and the intraoperative frozen section serve as the basis for decision-making. New imaging techniques and standardization in frozen section have significantly improved this in recent years. However, limitations remain due to time delays as well as more difficult correct anatomical assignment in the follow-up. Alternative intraoperative techniques may overcome this limitation in the future. Patient-derived organoids have emerged as an important new research vehicle in recent years. They are based on tumor stem cells that, under special culture conditions, form three-dimensional replicas of the original tissue. This makes them ideally suited for testing individual system therapies but also as a validation technique for new intraoperative diagnostic procedures. The Research Training Group 2543/I, which is funded by the German Research Foundation, is researching the potential of new diagnostic methods in an interdisciplinary team regarding validation in addition to intraoperative frozen sections.

[Rosai-Dorfman disease as a rare cause of a pancreatic mass]

The CT and MRI scans of a 70-year-old male patient revealed a mass in the pancreatic head and a 2.8-cm peripancreatic lymph node. Under steroid therapy the mass did not show regression. Finally, a pancreatoduodenectomy was performed. Histologically, Rosai-Dorfman disease (RDD) was diagnosed. RDD is a rare histiocytic disorder with usually nodal but sometimes also extranodal involvement. Herein we report a rare case of extranodal RDD with intrapancreatic localization.

Memento for interprofessional learning

The vast increase of technical, diagnostic, and treatment possibilities and deepened understanding of molecular biology has revolutionized diagnosis and treatment of cancer and thus has great impact on pathology. Different professionals are responsible for proper evaluation of the results and their translating into an accurate diagnosis and appropriate treatment. Next to expertise, a close interaction between clinical molecular biologists, pathologists, and oncologists is required; it is crucial that these professionals speak “the same language.” Key to this is communication skills and creating possibilities for collaboration in a meaningful context. Here, we present an interprofessional, educational workshop model and we describe the parameters that contribute to effective learning by specialists.

[Revised version of the 4th edition of the WHO classification of malignant lymphomas : What is new?]

After 8 years, the WHO has now published the updated version of the 4th edition of the classification of hematopoietic and lymphoid tumors. This update provides a conceptual rewrite of existing entities as well as some new provisional entities and categories, particularly among the aggressive B‑cell lymphomas. Important new diagnostic categories include the high-grade B‑cell lymphomas, the large B‑cell lymphoma with IRF4 rearrangement, and the Burkitt-like lymphoma with 11q aberrations. Of particular importance, new concepts concerning the taxonomy and classification of early lymphoid lesions or precursor lesions are included, such as the in situ follicular neoplasia or the in situ mantle cell neoplasia. In addition, the concept of indolent lymphoproliferations, such as breast-implant-associated anaplastic large cell lymphoma and the indolent T‑cell lymphoproliferative disorder of the gastrointestinal tract, has been strengthened. Finally, diagnostic criteria for existing lymphoma entities have been refined.

[Clonal evolution of early lymphoproliferations]

The identification and molecular characterisation of premalignant precursor lesions of lymphomas, such as monoclonal gammopathy of unknown significance (MGUS) and the so-called in situ lymphoproliferations, has made significant progress in the recent years. The in situ follicular neoplasia (ISFN), the best-characterised entity, is by definition not identifiable by morphology and represents a t(14;18)+ precursor lesion of follicular lymphoma with characteristic immunophenotype, low potential for progression, and already identifiable secondary genetic alterations. The use of high-throughput genetic techniques on microdissected tissues has generated novel insights into clonal evolution and biological progression of early lesions and documented that an isolated genetic analysis is insufficient to understand the complexity of proliferations.

[Aggressive B‑cell lymphomas : Recommendations from the German Panel of Reference Pathologists in the Competence Network on Malignant Lymphomas on diagnostic procedures according to the current WHO classification, update 2017]

The update of the 4th edition of the WHO classification for hematopoietic neoplasms introduces changes in the field of mature aggressive B‑cell lymphomas that are relevant to diagnostic pathologists. In daily practice, the question arises of which analysis should be performed when diagnosing the most common lymphoma entity, diffuse large B‑cell lymphoma. We discuss the importance of the cell of origin, the analysis of MYC translocations, and the delineation of the new WHO entities of high-grade B‑cell lymphomas.

Multicenter validation of cancer gene panel-based next-generation sequencing for translational research and molecular diagnostics

The simultaneous detection of multiple somatic mutations in the context of molecular diagnostics of cancer is frequently performed by means of amplicon-based targeted next-generation sequencing (NGS). However, only few studies are available comparing multicenter testing of different NGS platforms and gene panels. Therefore, seven partner sites of the German Cancer Consortium (DKTK) performed a multicenter interlaboratory trial for targeted NGS using the same formalin-fixed, paraffin-embedded (FFPE) specimen of molecularly pre-characterized tumors (n = 15; each n = 5 cases of Breast, Lung, and Colon carcinoma) and a colorectal cancer cell line DNA dilution series. Detailed information regarding pre-characterized mutations was not disclosed to the partners. Commercially available and custom-designed cancer gene panels were used for library preparation and subsequent sequencing on several devices of two NGS different platforms. For every case, centrally extracted DNA and FFPE tissue sections for local processing were delivered to each partner site to be sequenced with the commercial gene panel and local bioinformatics. For cancer-specific panel-based sequencing, only centrally extracted DNA was analyzed at seven sequencing sites. Subsequently, local data were compiled and bioinformatics was performed centrally. We were able to demonstrate that all pre-characterized mutations were re-identified correctly, irrespective of NGS platform or gene panel used. However, locally processed FFPE tissue sections disclosed that the DNA extraction method can affect the detection of mutations with a trend in favor of magnetic bead-based DNA extraction methods. In conclusion, targeted NGS is a very robust method for simultaneous detection of various mutations in FFPE tissue specimens if certain pre-analytical conditions are carefully considered.

The protective effect of human renal sinus fat on glomerular cells is reversed by the hepatokine fetuin-A

Renal sinus fat (RSF) is a perivascular fat compartment located around renal arteries. In this in vitro and in vivo study we hypothesized that the hepatokine fetuin-A may impair renal function in non alcoholic fatty liver disease (NAFLD) by altering inflammatory signalling in RSF. To study effects of the crosstalk between fetuin-A, RSF and kidney, human renal sinus fat cells (RSFC) were isolated and cocultured with human endothelial cells (EC) or podocytes (PO). RSFC caused downregulation of proinflammatory and upregulation of regenerative factors in cocultured EC and PO, indicating a protective influence of RFSC. However, fetuin-A inverted these benign effects of RSFC from an anti- to a proinflammatory status. RSF was quantified by magnetic resonance imaging and liver fat content by ¹H-MR spectroscopy in 449 individuals at risk for type 2 diabetes. Impaired renal function was determined via urinary albumin/creatinine-ratio (uACR). RSF did not correlate with uACR in subjects without NAFLD (n = 212, p = 0.94), but correlated positively in subjects with NAFLD (n = 105, p = 0.0005). Estimated glomerular filtration rate (eGRF) was inversely correlated with RSF, suggesting lower eGFR for subjects with higher RSF (r = 0.24, p < 0.0001). In conclusion, our data suggest that in the presence of NAFLD elevated fetuin-A levels may impair renal function by RSF-induced proinflammatory signalling in glomerular cells.

[Differential diagnostic specific skin infiltrates in chronic myelomonocytic leukemia]

A 72-year-old male patient presented with multiple erythematous plaques on the lower arms, lower legs and feet. The patient suffered from rheumatoid arthritis and accompanying interstitial granulomatous dermatitis under treatment with tocilizumab. Several months prior to presentation a chronic myelomonocytic leukemia (CMML) had been diagnosed. The skin biopsy showed a perivascular infiltration of medium-sized cells with positivity for CD123, CD303 and CD4 with a low proliferation activity so that a diagnosis of a CMML-associated proliferation of plasmacytoid dendritic cells was made. The differential diagnosis of specific cutaneous infiltrates in CMML is discussed.

[Pulmonary infection in neutropenia]

MEDICAL HISTORY AND CLINICAL COURSE: A 42-year-old patient with hairy cell leukemia had been treated for 3 years by a hematologist in private practice. Initially the patient received 1 course of cladribine upon which the disease went into complete remission. 6 weeks ago a relapse was diagnosed and combination therapy with cladibrin and rituximab was initiated. Now the patient presented to the emergency room with shortness of breath and pain when breathing.

INVESTIGATIONS, TREATMENT AND COURSE

In the chest x-ray, patchy infiltrates and pleural effusions were found on both sides. The subsequently performed computed tomography showed bilateral compactions with an Halo suspicious for fungal infiltrates. Upon admission to the hospital, an empirical antibiotic therapy with clarithromycin and piperacillin/tazobactam was initiated, which was later escalated to meropenem and linezolid. Additionally, an antifungal therapy with voriconazole was started and later switched to liposomal amphotericin B. At his admission, a positive aspergillus antigen could be detected in the microbiological laboratory. Under antimycotic treatment the aspergillus antigen was repeatedly negative. The patient presented with pronounced cytopenias and after a switch of therapy to vemurafenib and filgrastim, the hematopoiesis could only be stimulated insufficiently. The patient was transferred to the intensive care unit three days after admission with severe respiratory failure. He died on day 8 after admission. AUTOPSY AND DIAGNOSIS: Diagnosis was consistent with relapse of hairy cell leukemia with positive BRAF mutation and a bone marrow infiltration > 80 %. Autopsy revealed a significant hepato-splenomegaly, a lack of erythro-, granulo- and thrombopoiesis. Clots interspersed with fungal hyphae were found in both lungs and an infarction of the spleen with evidence of fungal hyphae was detected. The cultural findings post mortem on yeast or mold were negative.

CONCLUSION

Patients with refractory hairy cell leukemia and prolonged neutropenia are at increased risk for systemic fungal infections. Therefore, prohylactic antimycotic therapy should be considered early in this group of patients. The therapeutic approach of vemurafenib in treatment-refractory hairy cell leukemia is promising and offers an additional treatment option. In the present case, the patient could unfortunately not be stabilized due to the septic complications.

CNS metastases in breast cancer patients: prognostic implications of tumor subtype

Development of brain metastases (BM) in breast cancer leads to limited survival. The therapeutical options are limited. There are less data about the risk factors and prognostic importance in BM. Objective is to investigate predictors of central nervous system metastases and outcome after diagnosis of BM according to tumor subtype. Based on medical records, 80 consecutive patients with primary non-metastatic operable breast cancer, treated at Department of Gynecology, University of Tübingen, and who developed BM during follow-up, were retrospectively analyzed. Clinicopathological parameters and their prognostic impact were evaluated. A node involvement (40 %), ER/PR negative (53.75 vs. 61.25 %), triple negative (28.75 %) and HER2+ status (40 %) were associated with BM. BM in breast cancer patients lead to a shortened survival. In cerebral metastatic breast cancer patients with HER2-negative and triple-negative, patients had significant shorter survival after detection of BM compared with HER2-positive and non-triple-negative patients (p = 0.001; p = 0.03). Risk of BM varies significantly by subtype. Understanding the biology of metastases can help categorize patients into prognostically useful categories and tailor treatment regimens for individual patients. Prospective clinical trials would be required for evaluating the potential role of screening for asymptomatic BM and of treatment of triple-negative patients.

23-Year-Old Female with an Inflammatory Myofibroblastic Tumour of the Breast: A Case Report and a Review of the Literature

Purpose: Inflammatory myofibroblastic tumours (IMT) are a subcategory of inflammatory pseudotumours (IPT). They arise most commonly in the abdominopelvic region, lung and retroperitoneum, but virtually any anatomical site may be involved. Predominantly children and adolescents are affected and there is a tendency for local recurrence. In the literature up to the present, 20 patients have been reported with an IPT/IMT of the breast. We would like to present another patient with this unusual tumour entity of the breast and discuss the literature. Patient and Examinations: A 23-year-old woman presented with a painless lump in her left breast. There was no history of breast cancer in her family. Sonography showed a hypoechoic heterogeneous solid mass with irregular margins. A core needle biopsy revealed a tumour of high cellularity and a densely collagenous background. Immunohistochemically, the spindle-shaped cells were immunoreactive to smooth muscle actin and ALK-1 protein. Additional FISH analysis proved ALK rearrangements on chromosome 2p23 leading to the diagnosis of an IMT. Wide surgical excision was performed with no evidence of local recurrence after 12 months. Conclusion: Three of the above mentioned 20 patients with IMT/IPT of the breast developed a recurrent tumour, none presented with distant metastasis. A significant recurrence rate of 15 % leads to a clinically and sonographically close follow-up in these patients.

[Mesothelial proliferation in rectal cancer]

In an epiphrenic lymph node of a 55 years old female patient who underwent surgical resection of a rectal adenocarcinoma epitheloid proliferations with papillary and solid growth pattern were seen additional to a metastasis of the carcinoma. Adjacent vessels contained similar infiltrates. Immunohistochemically a co-expression of pan-keratin, calretinin and WT1 was seen, suggestive for a diagnosis of a metastasis of a malignant mesothelioma. However, radiologic examination yielded no morphologic correlate to this suspicion. Further immunohistochemical work-up showed positivity for desmin, negativity for EMA, GLUT1, p53 and a low ki67-fraction of 2-3 %. Therefore, a final diagnosis of benign mesothelial proliferations disseminated into the lymph node and the adjacent vessels was made.