Does the Method of Biopsy Affect the Incidence of Sentinel Lymph Node Metastases?

More detailed examination of the sentinel lymph node (SLN) in breast cancer has raised concerns about the clinical significance of micrometastases, specifically isolated tumor cells detected only through immunohistochemical (IHC) staining. It has been suggested that these cells do not carry the same biologic implications as true metastatic foci and may represent artifact. A retrospective institutional review board-approved review was conducted on clinically node-negative breast cancer patients who underwent SLN biopsy (SLNB) between 1997 and 2003. Retrospective analysis of tumor characteristics and the method of the initial diagnostic biopsy were correlated with the presence and nature of metastatic disease in the SLN. Of 537 SLNBs, 123 (23%) were hematoxylin-eosin (H&E) positive. SLN positivity strongly correlated with tumor size (p<0.001) and tumor grade (p=0.025), but not with the method of biopsy (needle versus excisional biopsy). Prior to July 2002, we routinely evaluated H&E-negative SLNs with IHC (n=381). Of the 291 H&E-negative patients, 26 had IHC-only detected micrometastases (9%). The likelihood of detecting IHC-only metastases did not correlate with tumor size or grade, but was significantly higher in patients undergoing excisional biopsy than core needle biopsy. While the method of biopsy has no demonstrable effect on the likelihood of finding metastases in the SLN by routine serial sectioning and H&E staining, it may significantly impact the likelihood of finding micrometastases by IHC. IHC should not be used routinely in the evaluation of the SLN and caution should be used when basing treatment decisions (completion axillary lymph node dissection or adjuvant therapy) on IHC-only detected micrometastases.     

A left knee wound complication by non-Hodgkins lymphoma in bilateral total knee arthroplasties

A 70-year-old woman with a history of bilateral primary knee osteoarthritis presented with a left knee wound complication, a non-Hodgkins lymphoma, after bilateral total knee arthroplasties. After exploring several etiologies, the evidence in this unusual case suggests a coincidental preexisting lymphoma.

Overcoming peripheral nerve gap defects using an intact nerve bridge in a rabbit model

This study investigated the intact nerve bridge technique for overcoming peripheral nerve gap defects in a rabbit model. To create the intact nerve bridge, a 1-cm segment of the peroneal nerve is resected leaving a gap defect. The proximal and distal peroneal nerve stumps are sutured 1 cm apart, in an end-to-side fashion, to the intact tibial nerve epineurium. Four experimental groups were used (n = 10): primary repair of resected segment; intact nerve bridge; nerve autograft; and gap in situ control. Evaluation after 12 weeks included measurement of isometric muscle contraction force, axonal counting, wet muscle weights, and histologic examination. The results of this study support two main conclusions, in a rabbit model: (a) regenerating axons can use the epineurium of an intact nerve to bridge a gap defect; (b) there is no significant difference in the functional recovery between standard nerve autografts and the intact nerve bridge technique.     

In vivo imaging of the human zonular apparatus with high-resolution ultrasound biomicroscopy

· Background: To investigate the potential of high-resolution ultrasound biomicroscopy (UBM) for studying the zonular apparatus of human beings in vivo. · Methods: Using transducer frequencies of 34 MHz and 50 MHz, criteria were developed to identify transcorneal and transscleral sections that allowed reproducible identification of the different fiber groups of the zonular architecture. For that purpose, 10 volunteers between the ages of 14 and 41 years underwent high-resolution ultrasound biomicroscopy under conditions of consensual far- and near-accommodation. The online video recordings of the respective UBM investigations were afterwards analyzed image by image. Good visibility of zonular fibers was obtained when the ultrasound wave propagation comprised an angle close to 90° with the fiber orientation and when the oscillations of the UBM scan had a strict radial orientation towards the limbus and avoided, simultaneously, the ciliary processes. · Results: In all the volunteers, high-resolution ultrasound biomicroscopy imaged the zonular fiber groups known from histology. In addition, it detected fibers that do not follow the course of the inner ciliary body surface but take a direct route from the ora serrata to the lens. It also demonstrated that fibers that seem to change direction at crossings with other fibers. Under conditions of near-accommodation, the zonular fibers showed signs of relaxation. · Conclusions: High-resolution ultrasound biomicroscopy seems well suited for in vivo investigations of the zonular apparatus and of accommodation in man. The results support the fundamental features of the Helmholtz theory on accommodation. Received: 8 June 1998 Revised version received: 7 September 1998 Accepted: 14 September 1998     

ERCP in evaluating the mode of therapy in pancreatic pseudocyst

Twenty patients with ultrasonographic or computed tomographic diagnosis of pancreatic pseudocyst were referred for endoscopic retrograde cholangiopancreatography (ERCP). Two of these were found at laparotomy not to have pseudocysts and were excluded. Pancreatography was successful in 15 out of 18 cases (83%) and cholangiography in 12 out of 18 cases (67%). Three types of pseudocysts were noticed according to the communication of the pseudocyst to the main pancreatic duct and the presence of pancreatic duct stenosis. Successful treatment included two spontaneous resolutions, two internal drainages and three left pancreatic resections. In the eight percutaneous external drainages four recurrences (50%) occurred, one after closure of temporary pancreatocutaneous fistula. All the recurrences occurred in Type III pseudocysts with communication of the pseudocysts to stenotic main pancreatic duct. In these cases internal drainage would have been the preferable treatment method. We believe that by ERCP one can identify pseudocysts not suitable for external drainage.     

Promyelocytic leukemia protein in mesenchymal stem cells is essential for leukemia progression

The dynamic interactions between leukemic cells and cells resident within the bone marrow microenvironment are vital for leukemia progression. The lack of detailed knowledge about the cellular and molecular mechanisms involved in this cross-talk restricts the design of effective treatments. Guarnerio et al. (2018) by using state-of-the-art techniques, including sophisticated Cre/loxP technologies in combination with leukemia mouse models, reveal that mesenchymal stem cells via promyelocytic leukemia protein (Pml) maintain leukemic cells in the bone marrow niche. Strikingly, genetic deletion of Pml in mesenchymal stem cells raised survival of leukemic mice under chemotherapeutic treatment. The emerging knowledge from this research provides a novel target in the bone marrow niche for therapeutic benefit in leukemia.