Clinical anatomy of the popliteal artery and its implications in total knee arthroplasty: a systematic review and meta-analysis.

The popliteal artery (PA) is a lower extremity arterial vessel, a continuation of the superficial femoral artery. PA may be injured in the majority of total knee arthroplasty (TKA), as well as arthroscopic surgeries which may lead to acute ischemic injury. Our objective was analyzing morphometry of PA in relation to other structures both in flexion and extension of the knee, highlighting discrepancies in the PA's location in varying positions. Literature was reviewed in regards to morphological qualities, prevalence rates, and variants of PA were pooled. Five cadaveric and 14 radiological studies were included, totalling 1473 lower limbs. We found that PA, when nearing bone, was more predictable and fixed as seen in axial plane one and two centimeters distal to joint line at 0 degrees flexion. The distance between PA and posterior tibial cortex was estimated at 3.3 mm with 95% confidence interval (CI) 2.6-4.1 and 7.8 mm (95% CI 5.1-10.5) respectively. Once PA passed over and nearing the joint it had larger discrepancies with distance comparing the knee in 0 vs 90 degree flexion. Due to rise of TKA, arthroscopic surgeries and connected vascular complications PA has been investigated more frequently, and while majority of publications describes relationships between vessels of popliteal area and specific landmarks conducted with knee in extension, our study also implemented data regarding knee flexion thus encompassing the problem in a more dynamic manner. We believe this provides superior data for identification of PA, especially during knee surgery.

Follicular lymphoma and marginal zone lymphoma: how many diseases?

Follicular lymphoma (FL) and marginal zone lymphoma (MZL) are indolent mature B-cell neoplasms with variable clinical presentation and distinct histopathologic features. Recent advances in the biology and molecular characteristics of these lymphomas have further expanded our understanding of the heterogeneous nature of these lymphomas, with increasing recognition of specific disease entities within the broader categories of FL and MZL. Here, we discuss the conclusions of the 2022 International Consensus Classification of Mature Lymphoid Neoplasms (2022 ICC) dealing with FL, and review differences with the proposed WHO 5th Edition classification. We review issues related to grading and alternative forms of FL especially those lacking the genetic hallmark of FL, the t(14;18) chromosomal alteration. Among them, t(14;18)-negative CD23+ follicle center lymphoma has been proposed by the 2022 ICC as a provisional entity. Other follicle center-derived lymphomas such as pediatric-type follicular lymphoma, testicular follicular lymphoma, primary cutaneous follicle center lymphoma, and large B-cell lymphoma with IRF4 rearrangement are considered distinct entities separate from conventional FL. Importantly, large B-cell lymphoma with IRF4 rearrangement introduced as a provisional entity in the WHO 2017 is upgraded to a definite entity in the 2022 ICC. We also discuss diagnostic strategies for recognition of MZLs including splenic MZL, extranodal MZL (MALT lymphoma), and primary nodal MZL. The importance of molecular studies in the distinction among marginal zone lymphoma subtypes is emphasized, as well as their value in the differential diagnosis with other B-cell lymphomas.

Rare Case of Diffuse Large B-Cell Lymphoma Mimicking Acute Monocytic Leukemia, Associated with Complex Karyotype.

OBJECTIVE: Diffuse Large B-Cell Lymphoma (DLBCL), NOS, constitutes 25-35% of adult non-Hodgkin lymphomas in developed countries, and a higher percentage in developing countries; older people are prone to the disease. Three frequent morphological variants have been recognized, including centroblastic, immunoblastic, and anaplastic variants. However, there are still other rare morphological variants of DLBCL, presenting challenge in diagnosis and treatment. CASE PRESENTATION: A 62-year-old woman sought medical attention with a previous 6-month history of intermittent fever and leukocytosis. Bone marrow (BM) aspiration presented AML with acute monocytic leukemia-like morphologic features. The results of the immunophenotypic analysis suggested mature B cell lymphoma without obvious subtype characteristics. Lymph node biopsy indicated DLBCL of non-germinal centre B-cell subtype (n-GCB). Cytogenetic analysis of the BM cells revealed a 46,XX, trp(1)(q21q32),del(7)(q32q36),t(9;14)(p13;q32) [4]/46,XX [16] karyotype. The patient was diagnosed with EBV-positive DLBCL, NOS based on the combination of lymph node biopsy, clinical, cytological, immunophenotypic, and cytogenetic analyses. CONCLUSION: To date, no case reports of a patient diagnosed with DLBCL mimicking acute monocytic leukemia with complex karyotype have been reported. We present the case given its rarity, easy misdiagnosis, and poor prognosis. The case highlights the importance of awareness about the rare morphological variant to laboratory staff and hematologists.