Multiple 14G stereotactic core biopsies in the diagnosis of mammographically detected stellate lesions of the breast.

AIM: The aim of this retrospective study was to measure the accuracy of stereotactic guided 14 gauge core biopsy in distinguishing between benign and malignant causes of a mammographically detected stellate breast lesion and to assess the impact of the number of core samples taken on the sensitivity for detection of malignancy. MATERIALS AND METHODS: Seventy-two patients with mammographically detected stellate lesions of the breast formed the study group. All patients in the study group underwent multiple 14 gauge core biopsies using prone stereotactic breast biopsy equipment. The diagnostic accuracy of the technique was measured by retrospectively comparing the outcome with the core biopsy results. The result of each core sample was separately recorded to allow analysis of the effect of increasing the number of samples on accuracy. RESULTS: Nine of 72 (12%) did not have surgery. Forty of 72 (56%) had a benign surgical outcome and 23/72 (32%) a malignant surgical outcome [7/72 (10%) non-invasive, 16/72 (22%) invasive carcinoma]. The absolute sensitivity for multiple stereotactic guided core biopsies of stellate lesions for the detection of malignancy was 78% with a complete sensitivity of 100%. The sensitivity for the detection of invasive carcinoma was 94% (15 out of 16 patients). No statistically significant improvement in sensitivity was shown for multiple samples vs one sample, but in two patients, malignant tissue was only found in core samples 6-9, the first five cores showing atypia only. CONCLUSION: Multiple stereotactic guided 14 gauge core biopsies accurately distinguish malignant from benign causes of stellate breast lesions. When core biopsy histology is malignant, therapeutic surgery can be planned. When the core biopsy shows typical features of a benign radial scar, diagnostic surgical excision may not be required to confirm the diagnosis.Kirwan, S. E., (2000). Clinical Radiology55, 763-766.

Detection of Chlamydia psittaci DNA in avian clinical samples by polymerase chain reaction.

A polymerase chain reaction (PCR) assay was developed to detect. Chlamydia psittaci DNA in faeces and tissue samples from avian species. Primers were designed to amplify a 264 bp product derived from part of the 5' non-translated region and part of the coding region of the ompA gene which encodes the major outer membrane protein. Amplified sequences were confirmed by Southern hybridization using an internal probe. The sensitivity of the combined assay was found to be between 60 to 600 fg of chlamydial DNA (approximately 6 to 60 genome copies). The specificity of the assay was confirmed since PCR product was not obtained from samples containing several serotypes of C. trachomatis, strains of C. pneumoniae, the type strain of C. pecorum, nor from samples containing microorganisms commonly found in the avian gut flora. In this study, 404 avian faeces and 141 avian tissue samples received by the Central Veterinary Laboratory over a 6 month period were analysed by PCR, antigen detection ELISA and where possible, cell culture isolation. PCR performed favourably compared with ELISA and cell culture, or with ELISA alone. The PCR assay was especially suited to the detection of C. psittaci DNA in avian faeces samples. The test was also useful when applied to tissue samples from small contact birds associated with a case of human psittacosis where ELISA results were negative and chlamydial isolation was a less favourable method due to the need for rapid diagnosis.

Detection of Salmonella enteritidis in eggs by the polymerase chain reaction.

A polymerase chain reaction (PCR) for the specific detection of the gene sequence, sefA, encoded by all isolates of Salmonella enteritidis, was developed. The PCR could detect as few as four S enteritidis washed bacterial cells but egg contents inhibited the PCR. Eggs spiked with 50 S enteritidis bacterial cells were homogenised, inoculated into buffered peptone water and grown at 37 degrees C for 16 hours, when the PCR was successful. A positive internal control was developed to differentiate between true and false negative PCR results for the detection of S enteritidis. In a limited trial of the egg handling procedures and the PCR, one of 250 chickens' eggs from retail outlets was found to be contaminated with S enteritidis.