Histopathology for the diagnosis of infectious diseases

Histopathological examination of tissue biopsies for the identification of infectious organisms is a very important diagnostic tool. Conventional culture confirmation of tissue biopsies often fail to identify any pathogen as, first of all, invariably most of the tissue samples that are collected and sent for culture isolation are inappropriately collected in formalin, which prevents pathogen growth in culture media. Inadequate processing like grinding, etc. further hinders isolation. Presence of inhibitors like dead tissue debris, fibers, etc. also delays isolation. Microbiologists often lack expertise in identifying infectious pathogens directly from tissue biopsies by microscopic visualization. This review therefore acquaints microbiologists with the various methods available for detecting infectious agents by using histological stains. On histopathological examination of the tissue biopsy once, it is determined that a disease is likely to be due to an infection and has characterized the inflammatory response and hence associated microorganisms should be thoroughly looked for. Although some microorganisms or their cytopathic effects may be clearly visible on routine haematoxylin- and eosin-stained sections, additional histochemical stains are often needed for their complete characterization. Highly specific molecular techniques, such as immunohistochemistry, in situ hybridization and nucleic acid amplification, may be needed in certain instances to establish the diagnosis of infection. Through appropriate morphologic diagnoses and interlaboratory communication and collaboration, direct microscopic visualization of tissue samples can thus be very helpful in reaching a correct and rapid diagnosis.

Use of Port-A-Cath in pediatric cancer patients: Experience from a tertiary cancer center in south India

e20747

Background: Implanted subcutaneous (s.c.) central venous port accesses including Port-A-Cath (PAC) facilitate the administration of chemotherapy or blood products and are frequently used in children with cancer. We present our experience of PACs in paediatric cancer patients from a tertiary cancer centre in South India. Methods: A total of 20 patients with paediatric malignancies requiring PAC were included in the study. Aim was to review our experience of PAC and analyse the outcome in paediatric cancer patients in Indian setting. A record of all complications and final outcome were analysed. Results: A total of 20 PAC were placed. Disease distribution included ALL(80%), AML(5%), NHL(5%), neuroblastoma (5%) and RMS (5%). PAC has been in place for 2 to 36 months (cumulative 400 months). Portal infection (Coagulase-negative staphylococci) was observed in four patients of whom 3 patients had their PAC removed (portal occlusion also seen in one of the pt). Conclusions: Although, catheter-related infections demanded PAC removal in 15% of our patients, their benefits (excluding cost 300 $) argue for continued PAC use in the paediatric cancer population as it is safe and has many advantages compared to traditional CVCs in use. Strict indications, meticulous implantation technique, and adequate handling are, however, mandatory.

No significant financial relationships to disclose.

A second peritoneal cytology instead of the initial cytology as a prognostic factor in epithelial ovarian cancer

e16572

Background: Ovarian cancer (OvCa) is the most common gynecological malignancy causing death. Positive (+ve) peritoneal cytology is an important prognostic factor. The role of a repeat peritoneal washing after resection of the tumor at the time of surgery has not been evaluated in the past. Methods: A retrospective analysis of our prospective cohort database was undertaken. Patients (pts) diagnosed with OvCa between 2001–2007 were included in the study. All pts underwent debulking surgery with two peritoneal washings during surgery: one before and one after resection of the tumor. The primary outcome was overall survival. Exclusion criteria included second malignancy, refusal of chemotherapy, or non-surgical candidates. Only stage III andIV pts were included in the follow-up analysis. Results: Forty three pts were included in our study. Of these, 8 (gp A) had both peritoneal washings +ve for malignancy, 16 (gp B) had the first washing +ve and the second one negative (-ve) for malignancy, and 19 (gp C) had both washings -ve for malignancy. There was no significant difference in the demographics and grade of disease (Table). There was more serous histology in gp B as compared to gp A and gp C. The median length of stay was 13.2, 10.9, 9 days and the median CA 125 level at the time of diagnosis was 651, 440 and 445 in gp A, B and C respectively. Bowel was involved and required radical resection in 75%, 41.7%, and 26.3% in gp A, B, and C, however the rates of optimal cytoreduction were 75%, 84.6% and 90.9% respectively. The minimum follow-up was 12 months. The percentage of pts with persistent or recurrent disease was 62.5%, 41.7%, and 36.4% in gpA, B and C respectively. There was improved survival in gp C as compared to gp B and gp A. (42 months vs 23.5 months vs 13 months respectively). Conclusions: While preliminary, our study shows that at the time of debulking surgery of OvCa, a -ve peritoneal washing after resection of the tumor following an initial +ve washing is a possible independent prognostic factor. [Table: see text]

No significant financial relationships to disclose.

Correlation of bone marrow micrometastasis to TNM stage of colorectal tumors

e15039

Background: Bone marrow (BM) micrometastasis(M) has been shown to be an important prognostic factor in Breast Cancer. However, there is paucity of data for BMM in Colorectal Cancer(CrCa). Hence a study was undertaken to find any correlation between TNM staging with BMM in CrCa patients(pts). Methods: A total of 155 consecutive patients(pts) from March 2004-October 2008 with CrCa were included in the study. Prior to resection of the primary tumor, pts underwent bilateral posterior-superior-iliac spine BM aspiration and samples were examined for presence of micrometastasis by Automated Cellular Imaging System using Chroma Vision Cytokeratin Detection Kit to detect cells expressing CK 8 as defined by CAM 5.2 monoclonal antibody. BMM and TNM staging were recorded and analyzed for correlations. Results: Of 155 CrCa pts, 11.6%(18/155) were found to have BMM. BMM was positive(+ve) in 50%(9/18) bilaterally and 50%(9/18) unilaterally. BMM was +ve in 11.5%(13/113) of colon pts and 12%(5/42) of rectal pts. When analyzed by T stage in colon pts, BMM was present in 10.5%(2/19) of T1 pts, 16.6%(2/12) of T2 pts, 14% (6/42) of T3 pts, 37.5%(3/8) of T4 pts, and 16%(5/31) of M1 pts. Upon analyzing rectal cancer pts data, BMM was found in 8.3%(1/12) of T1 pts, 16.6%(3/18) of T3 pts and 16.6% (3/18) of M1 pts. Of 113 total Colon pts, 27%(31/113) had nodal disease without distant metastasis(stage III); 13%(4/31) of these pts had BMM with 60% (3/5) unilaterally and 40%(2/5) bilaterally. In the Rectal group, 16%(7/42) had stage 3 disease; 14% (1/7) of stage 3 rectal pts had BMM. Conclusions: BMM did not correlate with tumor size, nodal status or distant metastasis. This discrepancy between tumor stage and BMM suggests BMM to operate independently of TNM staging. Further studies correlating prognosis and disease free survival in +ve BMM pts are needed to examine the significance of BMM in CrCa.

[Table: see text]

No significant financial relationships to disclose.

The number of lymph node metastases as a prognostic indicator of disease-specific survival in the era of sentinel lymph node mapping in colon cancer

e15000

Introduction: Sentinel Lymph Node Mapping (SLNM) in colon cancer (CCa) is shown to be successful, sensitive and accurate. We aimed to evaluate the survival of patients (pts) undergoing SLNM in addition to the standard colon resection, compare it to pts without SLNM and correlate it to the number of LN metastasis. Methods: Staging and survival analysis from our prospective database (gpA, 195 pts) were compared to the Surveillance, Epidemiology, and End Results (SEER) database (gpB, 126,484 pts) between 1996–2003. All pts had invasive CCa. GpA pts underwent SLNM plus complete resection. The minimum follow up (F/U) was 5 years. The primary outcome was cancer-specific survival. Exclusion criteria were stage IV disease, 2nd malignancy, or lost to F/U. Cancer specific survival of gpA was then analyzed according to the number of positive LNs. Results: In gpA (195 pts), SLNM was successful in 99.7%, of pts with a sensitivity, negative (-ve) predictive value, and false -ve rates of 86.3%, 91.7% and 14.6% respectively. In 15.1% of node +ve pts, the disease was upstaged because of micrometastasis (0.2–2mm). In gpA, 128 pts were included, of which 17(13.3%) lost to F/U as compared to 89,483 pts included in gpB, of which 47,168 (52.7%) lost to F/U. The average number of LNs examined per pt was 15 in gpA as compared to 12.4 in gpB (p=<0.0001). The 5 year-cancer specific survival of pts in gpA vs gpB was 100% vs 94.9% in stage I, 91.2% vs 83.5% in stage II and 81.8% vs 63% in stage III disease. For gpA pts, the 5 year cancer-specific survival decreased from 95.0% in node -ve disease to 92.8% when 1 LN was +ve, 83.3% when 2 LNs were +ve and 71.4% when 3 or more LNs were +ve (Table). Conclusions: A significant number of pts with CCa are being upstaged and the true node -ve disease is being identified when SLNM is performed at the time of surgery leading to improved survival as compared to conventional surgery. Our study showed that the number of LN metastasis is a predictor of cancer specific survival even after SLNM in CCa. [Table: see text]

No significant financial relationships to disclose.

Advancing the spontaneous hypertensive rat model of attention deficit/hyperactivity disorder

To advance the spontaneous hypertensive rat (SHR) model of attention deficit/hyperactivity disorder (ADHD), experiments examined the SHR in tasks recognized to assess functioning of the prefrontal cortex or dorsal striatal. Tasks included odor-delayed win-shift (nonspatial working and reference memory), win-stay (habit learning), and attentional set-shifting (attention and behavioral flexibility). In Experiment 1, the SHR strain was compared with Wistar-Kyoto (WKY) and Wistar-Kyoto Hypertensive (WKHT) strains on the first 2 tasks. In Experiment 2, oral methylphenidate (1.5 mg/kg) and vehicle (water) were evaluated on all 3 tasks in SHR and WKY strains. Results demonstrated that the SHR made significantly more errors in the odor-delayed win-shift, win-stay, and attentional set-shifting tasks compared with the WKY. Similar performances in the WKY and WKHT indicated that deficits observed in the SHR were not related solely to hypertension. Treating the SHR with methylphenidate eliminated strain differences in all 3 tasks. These findings provide evidence that the SHR is a valid model for studying ADHD-associated neurocognitive deficits. Moreover, the current behavioral approach is appropriate to assess novel medications developed to target ADHD-associated neurocognitive deficits.

Utility of PET imaging in predicting the aggressiveness and histopathology of lymphoma

8085

Background: F (18)-fluorodeoxyglucose positron emission tomography (FDG-PET) is widely used in the staging and restaging of non-Hodgkin's lymphoma (NHL) and Hodgkin's disease (HD). Few studies have investigated whether the intensity of tumor FDG uptake, measured by standard uptake value (SUV), a semiquantitative measure, could differentiate between indolent and aggressive disease. The clinical utility of SUV in determining the aggressiveness of NHL and HD and in differentiating histopathological subtypes was investigated in the present study. Methods: FDG-PET studies and histopathology of patients with NHL and HD were evaluated retrospectively. Inclusion criteria include PET before any therapy or on relapse of the disease, no diagnosis of diabetes mellitus or other types of cancer and time interval of < 90 days between PET and biopsy. After reviewing the PET scans, the SUV of biopsy site were measured by drawing regions of interest. Mean ± SD of SUV was calculated for HD and various histopathological subgroups of NHL. Results: Fifty-five patients (mean age 58.1 ± 17.2 years, 30 males, 25 females, 13 patients with HD, 42 with NHL, among which 24 with aggressive and 18 with indolent NHL) were included. The mean SUV was 9.9 ± 7.8 for aggressive NHL, 4.1 ± 2.6 for indolent NHL and 11.5 ± 7.3 for HD. Mean SUV was statistically different between aggressive and indolent NHL (p < 0.001) and HD and indolent NHL (p < 0.001), but not between aggressive NHL and HD (p = 0.4). The SUV for the aggressive NHL can be subdivided further as follows: anaplastic (n =3, 15.1 ± 1.7), diffuse large cell (n=19, 9.6 ± 5.3) and follicular grade III (n=2, 8.1 ± 2.2). Indolent NHL included: mantle cell (n=1, 4.3), marginal zone (n=1, 6.3), small cleaved (n=12, 4.2 ± 3.5), low grade follicular (n=4, 3.2 ± 1.4) and small lymphocytic NHL (n=1, 2.3). Conclusions: Our study suggests that FDG- PET can distinguish aggressive from indolent lymphomas. There was a considerable overlap between HD and aggressive NHL.A SUV of seven or less indicates indolent lymphoma. PET could potentially differentiate between different histopathological subgroups of lymphomas. Future studies with greater sample size are warranted.

No significant financial relationships to disclose.

Correlation of bone marrow micrometastases with nodal status in gastrointestinal tumors

14577

Background: Presence of bone marrow micrometastases (BMM) is an important prognostic factor for patients (pts) with solid tumors. Sentinel lymph node (SLN) mapping (M) has been found to upstage pts with gastrointestinal (GI) malignancies. However, a direct correlation between the presence BMM and nodal metastases (mets) is lacking. Hence, a retrospective study was undertaken to determine the relationship between BMM and nodal status in various GI malignancies. Methods: A total of 159 consecutive pts with GI malignancies were analyzed. Of these, 6 pts with non-epithelial tumors were excluded. All pts underwent bilateral posterior-superior-iliac spine bone marrow (BM) aspiration. BM samples were examined for micrometastases by Automated Cellular Imaging System using ChromaVision Cytokeratin Detection Kit to detect cells expressing CK8 as defined by CAM 5.2 monoclonal antibody. When feasible, SLNM was performed followed by standard oncologic resection (n=105). The SLN were examined by H&E and immunohistochemical (IHC) staining. Results: A total of 153 pts were analyzed in the study. Of these 13.72% (21/153) were found to have BMM (CI 8.70–20.21, p=0.05). When analyzed by sites, the incidence of BMM was 33.3% (4/12) for stomach cancer, 9.1% (1/11) for pancreatic cancer, 12.36% (11/89) for colon cancer and 16.13% (5/31) for rectal cancer. No BMM were detected in pts with cancer of esophagus (n=7), small bowel (n=2) and liver (n=1). The BMM was positive bilaterally in 61.9% (13/21), and unilaterally in 38.1% (8/21). In pts who underwent SLNM (n=105), BMM were detected in 11.11% of SLN positive pts vs. 10.14% for SLN negative pts (p=0.87). For a subgroup of pts with colorectal cancer who underwent SLNM (n=97), BMM were detected in 9.67% of SLN positive pts vs. 9.09% for SLN negative pts (p=0.92) Conclusions: BMM did not correlate with nodal status for GI malignancies suggesting a possible different mechanism for metastases. Detection of BMM may have a significant clinical value in SLN negative pts who may benefit from adjuvant therapy.

[Table: see text]

No significant financial relationships to disclose.

Comparative analysis of bone marrow (BM) micrometastasis (M) with sentinel lymph node (SLN) status in early breast cancer (BRCa)

508

Background: While sentinel lymph node (SLN) metastasis (mets) and bone marrow (BM) micrometastases (M) provide prognostic information in breast cancer (BRCa) patients (pts), a definitive relationship between the two has not yet been proven. We hypothesize that the presence of BMM may not infer an increased risk of SLN mets due to differences in their mechanisms of spread. Methods: We conducted a 6-year retrospective study of 251 T1/T2 BRCa pts who underwent bilateral iliac crest bone marrow aspiration, SLN mapping, and either lumpectomy, partial mastectomy, modified radical mastectomy, or total mastectomy by a single surgeon. BM samples were examined for micrometastases by Automated Cellular Imaging System using Chroma Vision Cytokeratin Detection Kit to detect cells expressing CK 8 as defined by CAM 5.2 monoclonal antibody. Pts with BMM underwent repeat BM analysis after completion of adjuvant chemotherapy. Data was collected for SLN, BM, ER/PR and HER2/neu status. Results: There were 251 consecutive pts entered into the study. Of these, 27.5% (69/251) had SLN mets and 9.6% (24/251) had BMM. Of the pts with SLN mets, 11.6% (8/69) had BMM vs. 88.4% (61/69) with no BMM ( Table ). In pts with ER/PR negative (-ve) BRCa, 7.1% (2/28) had BMM vs. 92.9% (26/28) with no BMM and 25% (7/28) had SLN positive (+ve) vs. 75% (21/28) SLN -ve pts ( Table ). Of the pts with HER2/neu +ve BRCa, 13.1% (8/61) had BMM vs. 86.9% (53/61) with no BMM and 26.2% (16/61) were SLN +ve vs. 73.8% (45/61) SLN -ve pts. After completion of adjuvant chemotherapy all pts with BMM (n=24) converted to BM -ve status. Conclusions: No correlation was identified between BMM and SLN status in T1 and T2 BRCa pts. This study suggests that BMM can occur independently of SLN status. Furthermore, (-ve) ER/PR and (+ve) HER2/neu status did not have a direct correlation with either BMM or SLN mets. Pts with BMM status may benefit from adjuvant therapy. Long-term implications of BM (+ve) have to be evaluated by larger multi- center trials.

[Table: see text]

No significant financial relationships to disclose.

Comparison of two doses of ropivacaine for lumbosacral epidural analgesia in buffalo calves (Bubalus bubalis )

Six male buffalo calves aged from six to eight months and weighing 100 to 120 kg were used to evaluate the efficacy and safety of caudal epidural analgesia produced by doses of 37.5 mg (5 ml) and 75 mg (10 ml) ropivacaine (0.75 per cent). The study was completed in two phases. In phase 1, all the animals were used twice to evaluate the analgesic and clinical effects of two doses of ropivacaine. In phase 2, the animals were divided into two groups of three to evaluate the effects of two doses of ropivacaine on some haemodynamic and acid-base parameters. Signs of analgesia, as evidenced by a loss of response to pinprick stimulation, were recorded only at the tail, perineum and hindlimbs of the animals given 5 ml ropivacaine, but they extended from the tail to the thorax (T9) in the animals given 10 ml ropivacaine. The duration of analgesia was five to six hours in the animals given 5 ml ropivacaine and seven to eight hours in the animals given 10 ml ropivacaine. Animals of both groups became recumbent, but the score for ataxia was higher in the animals given 10 ml ropivacaine. The respiratory rate decreased significantly (P<0.05) below the baseline in the animals given 10 ml ropivacaine, but the rectal temperature, heart rate, mean arterial pressure, central venous pressure and acid-base and electrolyte parameters did not change significantly in either group.

Association between lumbar epidural injection and development of acute paraparesis in patients with spinal dural arteriovenous fistulas

SUMMARY

We report 3 patients with previously undiagnosed spinal dural arteriovenous fistulas (SDAVFs), who developed acute paraparesis following lumbar epidural steroid injection. MR imaging demonstrated spinal cord T2 hyperintensity, edema and/or enhancement of the conus, and intradural enlarged vascular flow voids. Spinal angiography confirmed SDAVFs arising from pedicles remote from the sites of the epidural steroid injection. Fistulas were eliminated with either endovascular or combination endovascular and open surgical approaches, with subsequent partial resolution of paraparesis.