Jonathan Myles

Histopathology of Human Coronary Atherosclerosis by Quantifying Its Chemical Composition With Raman Spectroscopy

BACKGROUND Lesion composition, rather than size or volume, determines whether an atherosclerotic plaque will progress, regress, or rupture, but current techniques cannot provide precise quantitative information about lesion composition. We have developed a technique to assess the pathological state of human coronary artery samples by quantifying their chemical composition with near-infrared Raman spectroscopy. METHODS AND RESULTS Coronary artery samples (n=165) obtained from explanted recipient hearts were illuminated with 830-nm infrared light. Raman spectra were collected from the tissue and processed to quantify the relative weights of cholesterol, cholesterol esters, triglycerides and phospholipids, and calcium salts in the examined artery location. The artery locations were then classified by a pathologist and grouped as either nonatherosclerotic tissue, noncalcified plaque, or calcified plaque. Nonatherosclerotic tissue, which included normal artery and intimal fibroplasia, contained an average of approximately 4+/-3% cholesterol, whereas noncalcified plaques had approximately 26+/-10% and calcified plaques approximately 19+/-10% cholesterol in the noncalcified regions. The average relative weight of calcium salts was 1+/-2% in noncalcified plaques and 41+/-21% in calcified plaques. To make this quantitative chemical information clinically useful, we developed a diagnostic algorithm, based on a first set of 97 samples, that demonstrated a strong correlation of the relative weights of cholesterol and calcium salts with histological diagnoses of the same locations. This algorithm was then prospectively tested on a second set of 68 samples. The algorithm correctly classified 64 of these new samples, thus demonstrating the accuracy and robustness of the method. CONCLUSIONS The pathological state of a given human coronary artery may be assessed by quantifying its chemical composition, which can be done rapidly with Raman spectroscopic techniques. When Raman spectra are obtained clinically via optical fibers, Raman spectroscopy may be useful in monitoring the progression and regression of atherosclerosis, predicting plaque rupture, and selecting proper therapeutic intervention.

RENAL CRYOSURGERY: EXPERIMENTAL EVALUATION OF TREATMENT PARAMETERS

OBJECTIVES Cryosurgery represents a minimally invasive alternative for the management of small or equivocal lesions of the kidney. We evaluated the relationship between ultrasonographic appearance and intrarenal temperatures and the effect of renal artery occlusion on the efficacy of the freezing process in a canine model. METHODS Ten animals were treated with intraparenchymal cryoablative therapy with (n = 5) or without (n = 5) renal artery occlusion using a rapid freeze technique. Intrarenal temperatures were measured 1.0 cm away from the cryoprobe at various times during the freezing process. The distance from the cryoprobe to the ice ball as monitored by ultrasonography was also determined. The contralateral kidney was removed to facilitate studies of renal function and all animals were killed on day 28 for autopsy and histopathologic examination. RESULTS A target temperature of less than -20 degrees C was achieved 3.1 mm behind the ice ball in all animals tested. The ice ball stabilized at a radius of 16 mm with prolonged treatment, suggesting that multiple probes will be required to treat renal lesions greater than 2.5 cm in diameter. Renal artery occlusion did not significantly alter the freezing process and provided no practical advantage. Renal function remained stable (final serum creatinine level 1.5 mg/dL or less) in all but 1 animal in which an obstructive stricture of the ureteropelvic junction developed. Effective tissue ablation was confirmed at the treatment site in all instances. CONCLUSIONS Renal cryoablative therapy is a nephron-sparing modality that can be delivered in a safe, efficacious, and reproducible manner. The treatment parameters defined in this study should allow for intelligent patient selection and rational administration of renal cryotherapy.

Raman Spectroscopy and Fluorescence Photon Migration for Breast Cancer Diagnosis and Imaging

We are developing optical methods based on near infra‐red Raman spectroscopy and fluorescence photon migration for diagnosis and localization of breast cancer. We demonstrate the ability of Raman spectroscopy to classify accurately normal, benign and malignant breast tissues, an important step in developing Raman spectroscopic needle probes as a tool for improving the accuracy of needle biopsy. We also show that photon migration imaging can be used to localize accurately small fluorescent objects imbedded in a thick turbid medium with realistic optical properties, thus demonstrating the potential of this technique for optical imaging.

Prognostic importance of resection margin width after nephron-sparing surgery for renal cell carcinoma

OBJECTIVES To examine the relationship between the width of the resection margin and disease progression in renal cell carcinoma (RCC) after nephron-sparing surgery (NSS). During NSS for RCC, it is standard practice to excise the tumor along with a surrounding margin of normal parenchyma (margin of resection) to ensure complete resection of the neoplasm. However, no agreement has been reached on how wide the margin of resection should be. METHODS We retrospectively reviewed the histopathologic sections and medical records of 69 patients with localized RCC who had undergone NSS between 1976 and 1988 to determine whether the resection margin, tumor size, TNM stage, and Fuhrman nuclear grade were associated with disease progression (defined as local tumor recurrence or metastasis). The mean postoperative follow-up interval was 8.5 years. RESULTS No association was found between the width of the resection margin and disease progression (P = 0.98, log-rank test). Both TNM stage and Fuhrman nuclear grade correlated with disease progression. Patients with T1-T2 tumors had lower progression (P <0.001, log-rank test), and increased Fuhrman nuclear grade correlated with more disease progression (P <0.001, log-rank test). CONCLUSIONS The width of the resection margin after NSS for RCC does not correlate with long-term disease progression. A histologic tumor-free margin of resection, irrespective of the width of the margin is sufficient to achieve complete local excision of RCC.

HER2/neu amplification in breast cancer: stratification by tumor type and grade.

The presence of HER2/neu gene amplification is prognostically and therapeutically significant for patients with breast cancer. We sought to determine whether a relationship exists between HER2/neu gene amplification and the histologic type and grade of tumor. The histologic features and corresponding HER2/neu amplification results of 401 cases of invasive breast carcinoma were reviewed. Lobular carcinomas were less likely than ductal carcinomas to have HER2/neu amplification. Amplification was less frequent in Scarff-Bloom-Richardson grade I ductal carcinomas than in grades 2 and 3. Metastatic carcinomas frequently displayed HER2/neu amplification (6/20 [30%]). Our results support a correlation between HER2/neu amplification and the histologic type and grade of breast cancer. We suggest reexamination of tumors diagnosed as Scarff-Bloom-Richardson grade I invasive ductal carcinomas or lobular carcinomas if the lesion displays HER2/neu amplification to assure the exclusion of a higher grade of lesion or of missed ductal components.

VASECTOMY REVERSAL FOR THE POST-VASECTOMY PAIN SYNDROME: : A CLINICAL AND HISTOLOGICAL EVALUATION

PURPOSE The cause of the post-vasectomy pain syndrome is unclear. Some postulated etiologies include epididymal congestion, tender sperm granuloma and/or nerve entrapment at the vasectomy site. To our knowledge nerve proliferation has not been evaluated previously as a cause of pain. Vasectomy reversal is reportedly successful for relieving pain in some patients. We report our experience and correlate histological findings in resected vasal segments with outcome to explain the mechanism of pain in these patients. MATERIALS AND METHODS We retrospectively reviewed the records of 13 men who underwent vasectomy reversal for the post-vasectomy pain syndrome. We compared blinded histological evaluations of the vasal ends excised at vasectomy reversal in these patients with those of pain-free controls who underwent vasectomy reversal to reestablish fertility. Controls were matched to patients for the interval since vasectomy. Histological features were graded according to the degree of severity of vasitis nodosum, chronic inflammation and nerve proliferation. RESULTS Mean time to pain onset after vasectomy was 2 years. Presenting symptoms included testicular pain in 9 cases, epididymal pain in 2, pain at ejaculation in 4 and pain during intercourse in 8. Physical examination demonstrated tender epididymides in 6 men, full epididymides in 6, a tender vasectomy site in 4 and a palpable nodule in 4. No patient had testicular tenderness on palpation. Unilateral and bilateral vasovasostomy was performed in 3 and 10 of the 13 patients, respectively. Postoperatively 9 of the 13 men (69%) became completely pain-free. Mean followup was 1.5 years. We observed no differences in vasectomy site histological features in patients with the post-vasectomy pain syndrome and matched controls, and no difference in histological findings in patients with the post-vasectomy pain syndrome who did and did not become pain-free postoperatively. CONCLUSIONS No histological features aid in identifying a cause of pain or provide prognostic value for subsequent pain relief. Vasectomy reversal appeared to be beneficial for relieving pain in the majority of select patients with the post-vasectomy pain syndrome.

Diagnosis of chloroquine cardiomyopathy by endomyocardial biopsy.

CHLOROQUINE and hydroxychloroquine are antimalarial agents that are often used in the treatment of collagen vascular diseases. However, both drugs can cause a toxic skeletal-muscle myopathy, the hi...

Renal Cell Carcinoma Invading the Urinary Collecting System: Implications for Staging

PURPOSE Current TNM staging of renal cell carcinoma is based on the tumor propensity for local extension (T), nodal involvement (N) and metastatic spread (M). Locally advanced renal cell carcinoma may involve the perirenal fat, adrenal glands, renal vein, vena cava and/or urinary collecting system. The existing TNM classification does not reflect the ability of renal cell carcinoma to invade the urothelium. We evaluated the incidence and characteristics as well as overall and cancer specific survival of renal cell carcinoma invading the urinary collecting system. METHODS AND MATERIALS We reviewed pathological findings in 504 kidneys from 475 patients with renal cell carcinoma who presented to our institution in a 3-year period. Urothelial involvement required evidence of gross or histological invasion of the renal calices, infundibulum, pelvis or ureter. Demographic and survival data were obtained from medical records and an institutional cancer registry for tumors invading the urothelium. Stage specific survival data were then compared with tumors not involving the urinary collecting system. RESULTS Definitive urothelial involvement by the primary tumor was interpretable in 426 of 504 kidneys. Invasion of the collecting system was identified in 61 of 426 cases (14%). Mean diameter of the invading lesions was 10.2 cm. (range 3 to 26). The majority of cases showed clear cell and sarcomatoid histology. Invasion by a papillary lesion was rare. Involvement of the collecting system was most common at the renal poles. Of 61 lesions invading the collecting system 48 (79%) were stage pT3 or greater, while only 13 (21%) were pathologically localized stage pT2 or less. Vascular invasion was identified in 38 renal cell carcinoma cases (62%) with urothelial involvement. A total of 16 cases (26%) were associated with vena caval thrombus. Invading tumors were high Fuhrman grade III or IV in 43 cases (70%). Overall disease specific survival was poor with a median of 19 months. In patients with localized stage pT1 or pT2N0M0 disease and urothelial invasion median disease specific survival was 46 months. CONCLUSIONS Renal cell carcinoma lesions involving the renal collecting system are characteristically large, high grade and high stage. Clear cell carcinoma most commonly invades, while invasion by papillary tumors is rare. Overall the prognosis for high stage lesions with urothelial involvement is poor and does not appear significantly different from the reported disease specific survival of patients with high stage lesions without urothelial invasion. Localized tumors 4 cm. or less, which are amenable to elective nephron sparing surgery, rarely invade the urothelium. However, when a low stage pT2 or less renal lesion involves the urinary space, survival appears worse than equivalently staged renal cell carcinoma without invasion. Including urothelial invasion into current TNM staging systems for renal cell carcinoma is unlikely to provide significant additional prognostic or therapeutic information.

Silver In Situ Hybridization (SISH) For Determination of HER2 Gene Status in Breast Carcinoma Comparison With FISH and Assessment of Interobserver Reproducibility

The importance of HER2 status in breast cancer management has focused attention on the ability of clinical assays to correctly assign HER2 amplification status. There is no consensus as to the best method for assessing HER2 status. Disadvantages of fluorescence in situ hybridization (FISH) testing include longer time required for staining and scoring slides, requirements for specialized training and fluorescence microscopy, and loss of the signal due to quenching of the fluorescent dye. Silver-enhanced in situ hybridization (SISH) is a rapid fully automated assay providing permanently stained slides that are interpreted by conventional bright field microscopy which enables pathologists to evaluate slides within the context of tissue morphology. This study evaluates the concordance between SISH and FISH assays in determining the status of HER2 gene amplification in a cohort of 298 primary invasive breast carcinomas. Furthermore, we assessed in detail the variables contributing to interobserver interpretive reproducibility of HER2 SISH among 10 pathologists. HER2 was quantified using the ratio of HER2 to CHR17 signals using the conventional historical interpretation scale and also by the American Society of Clinical Oncology/College of American Pathologists reporting scheme. For SISH status determined by consensus among 10 pathologists, overall concordance between SISH and FISH was identified in 288 of 298 cases (96.6%) using the conventional Food and Drug Administration approved criteria. Overall agreement was observed in 282 of 285 cases (98.9%) using the American Society of Clinical Oncology/College of American Pathologists result reporting scheme (with equivocal cases removed). In conclusion, SISH represents a novel approach for the determination of HER2 status in breast cancer. The overall concordance between SISH and FISH is excellent, and the interpretation of SISH results by pathologists is most reproducible using the HER2/CHR17 ratio.

Fluorescence in situ hybridization (FISH) as primary methodology for the assessment of HER2 Status in adenocarcinoma of the breast: a single institution experience.

The demand for both reflexed and primary fluorescence in-situ hybridization (FISH) testing in the clinical setting is increasing. Relevant literature has reported the incidence of HER2 overexpression in 20% to 30% of cases, but some reports suggest that HER2 gene amplification rates are substantially lower. Published data, however, on primary FISH assessment from a single institution is limited, especially information about the frequency of the anomalous genotypes defined by FISH. We report our experience with primary FISH testing in 742 consecutive cases of breast cancer, in the calendar year 2006. Eighty percent (595/742) of the breast cancer cases were not amplified for HER2 (HER2/CEP17=0.8-1.9), whereas 19% (142/742) of cases were HER2 amplified (HER2/CEP17≥2.0). Among the HER2-amplified cases, 3% (19/742) were low-level amplified (HER2/CEP17 ratio=2.0–2.5). Genotypic heterogeneity, defined as >5% but <50% of the tumor cells demonstrating HER2 gene amplification, was observed in 5% (40/7242) of the cases. HER2 monoallelic deletion (HER2/CEP17≤0.7) was demonstrated in 2% (12/742) of the cases and CEP17 monosomy (1 CEP17 signal in >80% of tumor cells) was observed in 2% (13/742). Polysomy, if defined as CEP17 spot count 3.0 or more in at least80% of tumor cells, was observed in 3% (20/742) of the cases. These data may be helpful as benchmarks for other institutions initiating primary FISH analysis for HER2 genotyping.