A morphological mimic: An NTRK3-rearranged spindle cell neoplasm presenting as a groin mass

Neurotrophic receptor tyrosine kinase (NTRK)-rearranged spindle cell neoplasms are a recently described group of soft tissue tumors. They commonly present as a painless mass on the extremities of children and young adults. They are characterized microscopically by a heterogeneous spectrum of infiltrative spindle cell proliferations, which can morphologically mimic several other spindle cell neoplasms. Their identification is vital, as they may be amenable to treatment with tyrosine kinase-targeted therapy. This case report describes a rare NTRK3-rearranged spindle cell neoplasm in the groin of a 29-year-old female and provides further clinical and morphological features of this entity.

Aggressive B-cell non-Hodgkin lymphomas: a report of the lymphoma workshop of the 20th meeting of the European Association for Haematopathology

Aggressive B-cell non-Hodgkin lymphomas are a heterogeneous group of diseases and our concepts are evolving as we learn more about their clinical, pathologic, molecular genetic features. Session IV of the 2020 EAHP Workshop covered aggressive, predominantly high-grade B-cell lymphomas, many that were difficult to classify. In this manuscript, we summarize the features of the submitted cases and highlight differential diagnostic difficulties. We specifically review issues related to high-grade B-cell lymphomas (HGBCLs) with MYC and BCL2 and/or BCL6 rearrangements including TdT expression in these cases, HGBCL, not otherwise specified, large B-cell lymphomas with IRF4 rearrangement, high-grade/large B-cell lymphomas with 11q aberration, Burkitt lymphoma, and pleomorphic mantle cell lymphoma. Since the workshop, the 5th edition of the WHO Classification for Haematolymphoid Tumours (WHO-HAEM5) and International Consensus Classification (ICC) 2022 were published. We endeavor to use the updated terminology.

Mediastinal large B cell lymphoma and surrounding gray areas: a report of the lymphoma workshop of the 20th meeting of the European Association for Haematopathology

Session 3 of the 2021 European Association for Haematopathology/Society for Hematopathology Workshop focused on mediastinal large B cell lymphomas and surrounding gray areas. One half of the session was dedicated to primary mediastinal large B cell lymphoma (PMBL) and included cases with classic clinicopathologic features, as well as cases with either morphologic or immunophenotypic variation, and PMBL-like cases with primary extramediastinal disease. The role of additional immunophenotyping and/or molecular testing to aid in the diagnosis of PMBL was discussed. The second half of the session focused on mediastinal and non-mediastinal gray zone lymphomas (GZL) with features intermediate between diffuse large B cell lymphoma (DLBCL) and classic Hodgkin lymphoma (CHL). Several cases illustrating the current challenges in separating this entity from PMBL/DLBCL and CHL were presented. There was discussion regarding the clinical and genetic differences between mediastinal and non-mediastinal GZLs. Rare cases of PMBL and GZL associated with EBV or follicular lymphoma were reviewed. Finally, several cases included in the session highlighted composite or sequential CHL and PMBL/DLBCL and/or GZL, highlighting challenges in separating such cases from GZL.

Lymphomas with plasmablastic features: a report of the lymphoma workshop of the 20th meeting of the European Association for Haematopathology

Lymphomas with plasmablastic features are a heterogeneous group of aggressive and mostly uncommon neoplasms of varied aetiologies, presenting in immunocompetent individuals as well as in immunodeficiency, associated with EBV and Kaposi sarcoma virus infections, and some as progression from indolent B-cell lymphomas. They show overlapping diagnostic features and pose a differential diagnosis with other aggressive B-cell lymphomas that can downregulate the B-cell expression programme. The spectrum of rare reactive proliferations and all lymphomas defined by plasmablastic features, together with an expanding range of poorly characterised, uncommon conditions at the interface between reactive lymphoid proliferations and neoplasia submitted to the session V of the 20th European Association for Haematopathology/Society for Hematopathology lymphoma workshop are summarised and discussed in this paper.

The spectrum of nodular lymphocyte predominant Hodgkin lymphoma: a report of the lymphoma workshop of the 20th meeting of the European Association for Haematopathology

Session 4 of the 2021 European Association of Haematopathology/Society for Hematopathology Workshop focused on nodular lymphocyte predominant Hodgkin lymphoma (NLPHL). First, the spectrum of immunophenotypic variations in NLPHL and the defining criteria for classic Hodgkin Lymphoma (CHL) were discussed. The added value of further immunophenotypic characterization of both tumor cells and microenvironment to support the differential diagnosis was presented. Next, unusual cases with combined growth patterns and evolution of morphological features over time were presented to explore the clinicopathological impact of presumed high-risk patterns. Based on a large collection of cases, the defining morphological, immunophenotypical, and gene expression features of T-cell/histiocyte-rich large B-cell lymphoma (THRLBCL) and THRLBCL-like NLPHL (pattern E) were reviewed to explore this challenging differential diagnosis and critically evaluate whether aggressive behavior and transformation of NLPHL can be predicted in practice.

Trauma or tumour: giant cell tumour of distal biceps tendon sheath, an unusual cause of elbow pain

We report the case of a middle-age lady who presented following minor trauma, with dominant-sided anterior elbow pain and swelling of 6 months in duration. She was assessed clinically, and underwent investigations, which confirmed features consistent with giant cell tumour (GCT) of distal biceps tendon sheath. She underwent uneventful en-bloc excisional surgery. She did not have radiotherapy. She is now 5 years postoperatively asymptomatic, with full function, and with no signs of recurrence.

Giant pseudoangiomatous stromal hyperplasia presenting in the breast of a prepubertal child

Large benign lesions of the breasts are rare in children. We present a case of a 35 cm mass, weighing 2.7 kg in a 13-year-old girl with small developing breasts. Despite the enormity of the lesion, the patient managed to keep it concealed from her parents for 8 months. While initially suspicious of sarcoma a diagnosis of pseudoangiomatous stromal hyperplasia was suggested radiologically and confirmed histologically. Excision with reduction mammoplasty was performed, care taken not to disrupt the remaining breast tissue to facilitate future breast development. 18 months on, the cosmetic appearance of the breasts is good, with healthy underlying breast tissue developing. To the best of our knowledge this case is the largest documented breast tumour of this type in a patient of this age and illustrates the challenge of treating such tumours in the developing breast.

Prognostic significance of hypoxia inducible factor-1α and vascular endothelial growth factor expression in patients with diffuse large B-cell lymphoma treated with rituximab

We evaluated hypoxia inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) expression and their prognostic significance in diffuse large B-cell lymphoma (DLBCL). Expression of HIF-1α and VEGF was studied in 78 patients and results correlated with clinicopathological and prognostic data. HIF-1α and VEGF were expressed in 67% and 84% of patients, respectively, and a significant correlation was demonstrated between them (p < 0.001). Outcome was analyzed according to treatment. HIF-1α positive patients given rituximab demonstrated improved outcome, with 5-year overall survival of 72% for those receiving rituximab versus 65% for those not receiving rituximab, and 5-year progression-free survival (PFS) 76% versus 57%. No correlation was demonstrated between HIF-1α and other prognostic biomarkers including BCL6, CD10 and MUM-1. We demonstrated significantly improved PFS (p = 0.003) in patients receiving rituximab and showing BCL6 overexpression. The results confirm the significant association between HIF-1α and VEGF expression and suggest that HIF-1α expression is a favorable prognostic factor in patients with DLBCL treated with rituximab.

Primary cutaneous CD30+ T-cell lymphoproliferative disorder following cardiac transplantation in a 15-year-old boy with Netherton's syndrome

Primary cutaneous T-cell lymphoproliferative disorders (PCTCLDs) are uncommon in organ transplant recipients. CD30+ PCTCLDs are rare in children and have not previously been reported following organ transplantation. We report a 15-year-old boy with Netherton's syndrome who developed CD30+ PCTCLD 6 years following a cardiac transplantation.

Amelioration of rat antigen-induced arthritis by liposomally conjugated methotrexate is accompanied by down-regulation of cytokine mRNA expression

OBJECTIVES

We examined the temporal changes in the expression of interleukin 1beta (IL-1beta), tumour necrosis factor alpha (TNF-alpha) and interleukin 6 (IL-6) in the rat antigen-induced arthritis (AIA) model and investigated how their expression was modulated following disease amelioration by liposomally conjugated methotrexate (G-MLV).

METHODS

On the day of arthritis induction (day 0), rats were treated with a single intra-articular injection of G-MLV, methotrexate (MTX), a dose of lipid equivalent to G-MLV (E-LIPO) or saline. On days 3 and 7 after disease induction, animals from each experimental group were killed. Joint tissue was examined histologically and for mRNA expression (IL-6, IL-1beta and TNF-alpha) using semiquantitative reverse transcription-polymerase chain reaction.

RESULTS

There was no significant difference (ANOVA) in knee swelling between MTX-, E-MLV- or saline-treated animals from day 0 to day 7. By day 1, G-MLV significantly reduced knee swelling (1.94+/-0.12 mm; P<0.0001) compared with rats treated with MTX (3.17+/-0.18 mm). G-MLV treatment also significantly inhibited the histological progression of AIA. This reduction in disease severity was accompanied by a reduction in IL-1beta mRNA expression in synovial tissue extracts on day 3 and IL-6 mRNA expression on both day 3 and day 7.

CONCLUSIONS

Liposomally conjugated MTX may exert its beneficial effects in experimental arthritis through IL-1beta and IL-6 inhibition.