Superior vena cava obstruction evaluation with MDCT.

OBJECTIVE: The purpose of this article is to review the CT findings associated with superior vena cava obstruction and to illustrate collateral venous pathways bypassing the obstruction as shown on MDCT. CONCLUSION: Multiple collateral venous pathways can form to bypass an obstruction of the superior vena cava. With its ability to acquire near isotropic data, MDCT allows high-quality reformations and thus exquisitely displays these venous collaterals and has the potential to aid in planning therapy to bypass the obstruction.

Utilization of Radiographic Imaging for Infant Hydronephrosis over the First 12 Months of Life.

PURPOSE: The workup and surveillance strategies for infant hydronephrosis (HN) vary, although this could be due to grade-dependent differences in imaging intensity. We aimed to describe the frequency of imaging studies for HN within the first year of life, stratified by initial HN grade, within a large regional healthcare system. Study Design and Data Source. Retrospective cohort using Intermountain Healthcare Data Warehouse. Inclusion criteria: (1) birth between 1/1/2005 and 12/31/2013, (2) CPT code for HN, and (3) ultrasound (U/S) confirmed HN within four months of birth. Data Collection. Grade of HN on initial postnatal U/S; number of HN-associated radiologic studies (renal U/Ss, voiding cystourethrograms (VCUGs), and diuretic renal scans); demographic and medical variables. Primary Outcome. Sum of radiologic studies within the first year of life or prior to pyeloplasty. Statistical Analysis. Multivariate poisson regression to analyze association between the primary outcome and the initial HN grade. RESULTS: Of 1,380 subjects (993 males and 387 females), 990 (72%), 230 (17%), and 160 (12%) had mild, moderate, and severe HN, respectively. Compared with those with mild HN, patients with moderate (RR: 1.57; 95% CI: 1.42-1.73) and severe (RR: 2.09; 95% CI: 1.88-2.32) HN had a significantly higher rate of imaging use over 12 months (or prior to surgery) after controlling for potential confounders. CONCLUSIONS: In a large regional healthcare system, imaging use for HN is proportional to its initial grade. This suggests that within our system, clinicians treating this condition are using a risk-stratified approach to imaging.

Necrotizing pneumonia caused by community-acquired methicillin-resistant Staphylococcus aureus: an increasing cause of "mayhem in the lung".

Although long recognized as a nosocomial organism, methicillin-resistant Staphylococcus aureus (MRSA) has been noted to have an increasing incidence in both immunocompromised and otherwise healthy people in the community. Community-acquired MRSA (CA-MRSA) is genetically distinct from hospital-acquired MRSA and frequently expresses the Panton-Valentine leukocidin toxin, which confers an aggressive necrotizing phenotype and is accompanied by a poor prognosis. We present a case of CA-MRSA pneumonia with the aim to alert the radiologist of the radiographic manifestations of this increasingly encountered and frequently fatal disease.

Completion axillary lymph node dissection minimizes the likelihood of false negatives for patients with invasive breast carcinoma and cytokeratin positive only sentinel lymph nodes.

OBJECTIVE: To document the incidence of metastatic disease in complete axillary lymph node dissections (CALND) of patients with invasive carcinoma after a sentinel lymph node (SLN) biopsy, positive only by immunohistochemical staining for cytokeratin (CK-IHC). METHODS: Sections of all SLNs, negative by routine histology, were immunostained and examined for cytokeratin positive cells. Sections of lymph nodes from CALND specimens were interpreted using routine hematoxylin and eosin (H&E) staining. RESULTS: A total of 409 patients (29.6%) had metastatic disease in at least one sentinel lymph node on H&E examination. Of 971 H&E negative patients, 78 (8.0%) were positive only by CK-IHC. Sixty-two of the CK-IHC positive only patients underwent CALND. Nine of these 62 patients (14.5%) had metastases identified in the CALND specimen. CONCLUSIONS: Because 14.5% of patients with invasive breast cancer and SLNs positive only by CK-IHC were found to have H&E positive lymph nodes on CALND, we conclude first, that CK-IHC should be used to evaluate SLNs, and second, that CALND should be considered when SLNs are positive by CK-IHC only. This approach will result in an absolute reduction of the false negative rate (absolute false negative rate reduced by 2.6% in our series).

Breast cancer in patients with prior augmentation: presentation, stage, and lymphatic mapping.

The purpose of this study was to determine whether breast cancer patients who had prior breast augmentation presented at a more advanced stage than nonaugmented breast cancer patients, and to determine the mode of presentation and effectiveness of lymphatic mapping and sentinel lymph node biopsy in this same group of patients. A total of 4186 breast cancer patients from 1987 to 2002 were reviewed. Patients who had augmentation before their diagnosis of breast cancer were compared with a control group of nonaugmented breast cancer patients. The Wilcoxon rank sum test was used to compare tumor size, node positivity, and stage. The patient's age at presentation was also compared by the two-sided pooled t test. Seventy-six patients who previously underwent augmentation were identified with 78 breast cancers. Seventy percent (48 of 69) were initially detected by palpation, whereas 30 percent (21 of 69) were initially identified mammographically. Fifty-three percent (n = 41) underwent mastectomy and 47 percent (n = 37) underwent a lumpectomy. This compares with a 63.6 percent (2615 of 4110) breast conservation rate in the nonaugmented population during the same time period. The two groups did not differ regarding (tumor) size (p = 0.77), nodal positivity (p = 0.32), or stage (p = 0.34). The mean time between implant placement and a diagnosis of breast cancer was 14 years. The average age of the patients who had previously undergone augmentation at breast cancer diagnosis was 49.5 years (SD, 9.0 years) versus 57.1 years (SD, 13.5 years) for the nonaugmented patients (p < 0.0001). Forty-nine of the patients underwent lymphatic mapping, with a 100 percent success rate in identifying the sentinel lymph node. There have been no clinically detected axillary recurrences in the patients who had a negative sentinel lymph node biopsy. Breast cancer patients who have undergone previous augmentation are more likely to present with a palpable mass. This initial mode of detection does not appear to translate into a larger tumor size or worse prognosis. Breast conservation and lymphatic mapping can be performed successfully in previously augmented patients.

Age and body mass index may increase the chance of failure in sentinel lymph node biopsy for women with breast cancer.

Age and body mass index (BMI) have been shown to correlate with an increased incidence of failure in identifying a sentinel lymph node (SLN). Mapping senior, overweight adults is common; therefore, the relationship of patient age and BMI on SLN biopsy success is essential. This study examines the mapping failures as they relate to age and BMI. From April 1994 to May 1999, patients underwent an injection of radiocolloid (450 mci) and blue dye (5 cc) prior to SLN biopsy. SLN biopsy failure was defined as lymph nodes being unidentifiable by blue dye or having an in vivo node radiocolloid count of less than 3:1 over background count. BMI was measured as (weight in pounds)(703)/(height in inches)(2); 1,356 patients were attempted for SLN mapping, and 54 failed (3.98%). The radioactive node count was inversely proportional to age ( p < 0.0001). The radioactive node count decreased by a mean of 34 counts per node with each additional year ( p < 0.001). The estimated odds ratios for success were 0.945 for age and 0.946 for BMI. Therefore, every increase of 1 year of age or one unit of BMI decreased the odds of success by approximately 5%. The mean BMI was 29.54 in failed patients and was 26.42 in successful mapping patients ( p = 0.042). Surgeons should be aware that node counts will decrease with increasing age and that increased age and BMI are potential risk factors for SLN mapping failure. However, increased age and/or BMI alone do not appear to be contraindications for SLN biopsy in older or overweight patients.

Effect of lymphatic mapping on diagnosis and treatment of patients with T1a, T1b favorable breast cancer.

OBJECTIVE: To investigate the incidence of nodal metastasis in a consecutive series of patients treated at the authors' institution with highly selective criteria, and to determine the impact that lymphatic mapping and sentinel node biopsy have on the detection of nodal metastases in this carefully selected patient population. METHODS: Study patients were selected from the 7,750 breast cancer patients entered into the authors' database from April 1989 to August 2001, based on the following criteria: nonpalpable, T1a and T1b, non-high nuclear grade tumors, without lymphovascular invasion. RESULTS: Of the 7,750 patients in the database 1,327 (17%) were found to have T1a and T1b lesions. Three hundred eighty-nine patients were confirmed to meet all four selection criteria. This represents 5% (389/7,750) of the authors' breast cancer patients and 29.3% (389/1,327) of the authors' T1a/T1b tumors. One hundred sixty patients were diagnosed before routine use of lymphatic mapping, and only one patient had a positive axillary lymph node. Two hundred twenty-nine patients underwent lymphatic mapping and sentinel lymph node biopsy, and 10 had a positive axillary lymph node. The difference in proportions of nodal positivity between the mapped and unmapped patients was significant. CONCLUSIONS: This study clearly demonstrates the ability of lymphatic mapping and a more detailed examination of the sentinel node to increase the accuracy of axillary staging. It has been argued that this highly selected group of breast cancer patients possessing retrospectively identified "favorable" characteristics does not require axillary staging. This select population represents only 5% of breast cancer patients in this series, and the authors do not believe they can be accurately identified preoperatively. Therefore, the authors strongly argue for evaluation of the axillary nodal status by lymphatic mapping.