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Biomedical subjects

J M Theaker

Publications and source records attributed to J M Theaker.

At least 37 records · Page 2Linked to original sources
PubMed2001

The role and histological classification of needle core biopsy in comparison with fine needle aspiration cytology in the preoperative assessment of impalpable breast lesions.

AIMS: To investigate the role of needle core biopsy (NCB) in the preoperative assessment of impalpable breast lesions, mainly derived from the NHS Breast Screening Programme (NHSBSP) and to assess our own modifications to a suggested system for the classification of breast NCBs. METHODS: The NCB, fine needle aspiration cytology (FNAC), and radiology scores from 298 women with non-palpable breast lesions presenting between January 1997 and December 1998, together with the open biopsy results (where available) were collated and analysed. RESULTS: The mean follow up period was 15.8 months (range, 5-28). The 298 NCB specimens were categorised as follows: unsatisfactory/non-representative (B1; n = 61; 20.5%), benign but uncertain whether representative (B2r; n = 52; 17.4%), benign (B2; n = 103; 34.6%), lesions possibly associated with malignancy but essentially benign (B3a; n = 9; 3.0%), atypical epithelial proliferations (B3b; n = 10; 3.4%), suspicious of malignancy (B4; n = 7; 2.3%), and malignant (B5; n = 56; 18.7%). Excision biopsy was performed in 43 cases within the B1 (n = 19), B2r (n = 8), B2 (n = 8), and the B3a (n = 8; data unavailable in one case) categories, revealing malignancy in 18 (42.8%) cases and in 65 cases within the B3b, B4, and B5 categories, revealing malignancy in 64 cases (98.5%). The sensitivity of NCB for malignancy was 87.7%, with a specificity and positive predictive value of 99.3% and 98.5%, respectively. FNAC had an inadequacy rate of 58.7%, a complete sensitivity of 34.5% and a specificity of 47.6%. CONCLUSIONS: This study confirms the value of NCB in the preoperative assessment of impalpable breast lesions. Two new categories are suggested for the NCB classification; category B2r for benign breast tissue where representativeness is uncertain, and the subdivision of category B3 into B3a for benign lesions potentially associated with malignancy (for example, radial scars and intraduct papillomas) and B3b for more worrisome atypical epithelial proliferations. These will aid the accurate audit of NCB and identify more clearly the intellectual pathway leading to a particular assessment.

Aged↗
PubMed2001

Predominant fatty variant of myofibroblastoma of breast.

Myofibroblastoma of the breast is an uncommon but well defined benign stromal tumour. This report describes a case in which the predominant histological component was mature adipose tissue and two further cases with a major adipocytic component. Although small foci of adipose tissue are a recognised feature of this tumour, the dominance of the histological pattern by fat has not been described previously, and the recognition of this variant is important to allow confident diagnosis and avoid confusion with other primary adipocytic or stromal lesions, especially in the setting of potential needle core biopsy of such a lesion.

Adipocytes↗
PubMed2000

Ber EP4 and epithelial membrane antigen aid distinction of basal cell, squamous cell and basosquamous carcinomas of the skin.

AIMS: Seventy-five skin tumours were studied to investigate the value of immunohistochemistry in differentiating basal cell, squamous cell and basosquamous carcinomas of the skin. METHODS AND RESULTS: Archived paraffin-embedded tissue samples of basal cell carcinomas (n = 39), squamous cell carcinomas (n = 23) and basosquamous carcinomas (n = 13) were stained immunohistochemically using a panel of antibodies. All of the basal cell carcinomas stained positively for Ber EP4, in contrast to the group of squamous cell carcinomas, that showed no staining. Basosquamous carcinomas all showed at least some areas of Ber EP4 positivity. None of the basal cell carcinomas, but most of the squamous cell carcinomas (22 of 23) expressed epithelial membrane antigen (EMA). Only one of the basosquamous carcinomas expressed EMA positivity focally. CAM 5.2, carcinoembryonic antigen (CEA) and 34betaE12 antibodies lacked specificity in relation to the different tumour types. CONCLUSION: Distinction of basal and squamous cell carcinomas of the skin can be readily achieved with routine immunohistochemistry using Ber EP4 and EMA. Identification of basosquamous carcinoma is also facilitated with this method.

Adolescent↗
PubMed1999

The value of central histopathological review of testicular tumours before treatment.

OBJECTIVE: To assess the value of central histopathological review of testicular tumours. MATERIALS AND METHODS: The histopathology reports of the referring hospital and central review were compared for all referred testicular specimens (201 orchidectomies and seven testicular biopsies) from 11 hospitals in one region, between 1992 and 1997. RESULTS: There were two main findings: First, there was a major discrepancy of tumour type in 12 specimens (6%). The most frequent change (in five cases) was from seminoma to nonseminomatous germ cell tumour (NSGCT). There were also difficulties with uncommon tumours such as spermatocytic seminoma, lymphoma and adenocarcinoma. Treatment was changed as result of the altered diagnosis in eight of these 12 patients. Second, there were discrepancies of interpretation of vascular invasion in 12 of 59 NSGCTs (20%). Differences of tumour elements recognized in NSGCTs were frequent. CONCLUSIONS: The errors discovered on central histopathological review of testicular tumours were significant, though small in number. This supports the idea of central review and is consistent with the specialization recommended in the Calman-Hine cancer arrangements.

Biopsy↗
PubMed1999

Polymerase chain reaction based human leucocyte antigen genotyping for the investigation of suspected gastrointestinal biopsy contamination.

BACKGROUND: Mislabelling or contamination of surgical specimens may lead to diagnostic inaccuracy, particularly within gastrointestinal pathology when multiple small mucosal biopsy specimens are commonly taken, and where a tiny fragment of foreign tissue may be indistinguishable from true biopsy material using histological assessment alone. AIMS: To assess the utility of polymerase chain reaction (PCR) based human leucocyte antigen (HLA) genotyping techniques for the investigation of potentially mislabelled or contaminated gastrointestinal biopsy specimens. PATIENTS: Ten cases (28 samples) in which mislabelling or contamination was suspected, comprising four upper gastrointestinal tract biopsies and six colonoscopic biopsy series. METHODS: Direct and nested PCR-sequence specific primer (SSP) based HLA class II genotyping was performed on DNA extracted from formalin fixed and paraffin wax embedded tissue (23 samples) or peripheral blood leucocytes (five samples). RESULTS: A full HLA-DRB1 genotype was determined in all 28 samples. In seven cases the HLA-DRB1 genotype of the putative contaminant was different to that of the corresponding reference tissue, confirming different individual origins for the contaminant and reference material. In one case the contaminant tissue was shown to possess the same HLA-DRB1 alleles as a second patient (probable source). In the remaining three cases the same HLA-DRB1 alleles were detected within the potential contaminant and reference tissues. CONCLUSIONS: PCR based HLA class II genotyping is a valuable tool for investigating potential contamination or mislabelling within gastrointestinal biopsy specimens and this report has confirmed contamination in seven of ten cases studied.

Adult↗
PubMed1999

HLA class II DRB1 and DQB1 allelic polymorphism and sclerosing lymphocytic lobulitis of the breast.

BACKGROUND: Sclerosing lymphocytic lobulitis is an inflammatory disorder of the breast. The pattern of inflammation, expression of HLA class II DR by breast epithelium and association with autoimmune disorders, particularly insulin dependent diabetes mellitus (IDDM), together suggest an autoimmune aetiology. AIM: To test the hypothesis that susceptibility to sclerosing lymphocytic lobulitis may be linked to patient HLA class II DRB1 alleles, particularly DRB1*03 and DRB1*04, suggested by a previous small uncontrolled study. METHODS: HLA class II DRB1 and DQB1 genotypes were compared between a series of 28 sclerosing patients with lymphocytic lobulitis and 300 controls, using polymerase chain reaction (PCR) based typing of DNA extracted from formalin fixed, paraffin embedded biopsies. RESULTS: Results from the 28 patients (nine with IDDM) showed an increased frequency of DRB1*04 compared with controls (61% v 33%, p = 0.01), but no significant differences for other genotypes. In patients with IDDM, the frequencies of DRB1*04 (89%, p = 0.001) and DQB1*0302 (100% v 21%, p = 0.0001)--a genotype that is in linkage disequilibrium with DRB1*04--were increased compared with controls. However, in the patients without IDDM, the frequencies of DRB1*04 (50%) and DQB1*0302 (14%) were not significantly increased. CONCLUSIONS: The increased frequency of HLA DRB1*04 in sclerosing lymphocytic lobulitis appears to reflect its association with IDDM, a condition in which DRB1*04 is increased in frequency.

Adult↗
PubMed1998

Malignant melanoma re-excision specimens--how many blocks?

AIMS: Wide local excision is commonly undertaken as part of the further management of cutaneous melanoma. Although the original excision is usually complete, pathologists vary considerably in their macroscopic handling and sampling of the wide excision specimens. This study evaluates the sampling of reexcision specimens and the information gained from histological examination of tissue blocks in order to develop guidelines for the handling of these specimens. METHODS AND RESULTS: The study group comprises 219 cases of melanoma which underwent initial biopsy followed by wider excision. The macroscopic appearance, number of blocks taken and presence of residual melanoma in the wide excision specimen was assessed. Residual melanoma was detected in the wide excision specimen in only four cases out of the 167 in which the original melanoma had been described as completely excised and in these cases the detection of a residual lesion reflected either advanced local disease at the time of the original excision, or an incompletely excised extensive radial growth phase. The sampling of wide excision specimens varied (range of blocks 1-12, average 3.1) but statistical analysis showed no undersampling of the wide excision specimens in which no residual lesion was found. CONCLUSIONS: These results show that detection of a residual lesion in wide excision specimens of melanomas previously completely excised is unusual and offers no additional clinically useful information. Random block taking in the absence of a macroscopic abnormality is therefore unlikely to be clinically useful. Guidelines for the gross handling of these wide excision specimens are proposed which are likely to save resources in most histopathology departments by reducing block numbers.

Humans↗
PubMed1998

HLA-DQB1*0303 and *0301 alleles influence susceptibility to and prognosis in cutaneous malignant melanoma in the British Caucasian population.

The presence of lymphocytic infiltrates within primary cutaneous malignant melanoma (CMM), documented spontaneous tumour regression and genetic linkage with chromosome six in familial cases all suggest that immunogenetic factors may modulate disease progression. An association has been suggested between HLA DQB1*0301 and CMM in US patients but no such investigation has been performed in the UK population. Polymerase chain reaction-based HLA class II DRB1, DQA1 and DQB1 typing of 99 UK-based CMM patients was performed using DNA extracted from archival formalin-fixed and paraffin wax-embedded surgical biopsies, enabling retrospective access to clinical follow-up data. An increase in frequency of the HLA DQB1*0303 genotype among CMM patients was identified compared to control subjects (19.2% vs 5.8%; Pc=0.003; RR=3.9) while HLA DQB1*0301 was associated with more advanced and therefore poorer prognosis primary tumours (e.g. HLA DQB1*0301 allele frequency: 20.1% vertical growth phase vs 4.0% horizontal growth phase; Pc=0.03; RR=6.1). These findings suggest that the HLA DQB1 locus, and in particular the HLA DQB1*0303 and *0301 alleles, may play an important role in determining the risk of development and the prognosis of CMM within the UK population.

Female↗
PubMed1997

The growing teratoma syndrome in a nongerminomatous germ cell tumor of the pineal gland: a case report and review.

BACKGROUND: The growing teratoma syndrome is a recognized complication of metastatic nonseminomatous germ cell tumors of the testis and is managed surgically. It may also occur in intracranial nongerminomatous germ cell tumors. METHODS: The authors performed an English language computer search using the EMBASE data base (from January 1980 to December 1996) for pineal tumors, read all abstracts, and then selected all articles pertaining to germ cell tumors at this site. RESULTS: The case history of a 19-year-old male who presented with a pineal nongerminomatous germ cell tumor, which was treated with chemotherapy, is reported. Despite normalization of raised tumor marker levels, the pineal mass enlarged during chemotherapy. This was excised and proved to be a mature teratoma. A review of the literature regarding this complication of intracranial germ cell tumors is also presented. CONCLUSIONS: The authors believe this to be the first reported case of growing teratoma syndrome in the pineal gland of an adult patient, two previously reported cases occurred in children. The authors conclude that the pineal gland is an unusual but important site in which to recognize the growing teratoma syndrome.

Adult↗
PubMed1997

Nested polymerase chain reaction-based HLA class II typing for the unique identification of formalin-fixed and paraffin-embedded tissue.

Human leukocyte antigen (HLA) genotyping is routinely performed prior to organ transplantation using peripheral blood leukocyte-derived DNA. In addition, polymerase chain reaction (PCR)-based methods have permitted HLA genotyping using DNA extracted from formalin-fixed and paraffin-embedded tissue, with proven applications in HLA-disease association studies and surgical biopsy identification. The utility of current techniques may be limited by the poor yield of intact DNA from such paraffin biopsies. This paper describes a new nested PCR-based HLA class II genotyping method which reliably detects HLA DRB alleles within DNA extracted from even extremely small paraffin biopsies. This method comprises initial PCR amplification of exon II sequences of the HLA DRB1, 3, 4, and 5 genes using generic PCR primers. Identification of the HLA DRB1 alleles and detection of the DRB3, 4, and 5 genes is then performed using a series of separate individual second-round PCR reactions, each of which contains PCR primer pairs detecting a single HLA DRB allele or group of alleles (PCR-SSP). The ability of this method to detect 19 individual HLA DRB1 alleles or groups of alleles, covering all common DRB1 specificities, was confirmed via concordant results when compared with 'direct' (single amplification step) PCR-SSP analysis of one cell line-derived and nine peripheral blood-derived DNA samples, and with five DNA samples extracted from paraffin biopsies. The technique was then successfully applied to 11 further paraffin biopsy-derived DNA samples, of which ten were untypable by 'direct' PCR-SSP analysis, from five cases in which doubt existed as to the individual origin of the tissues.

Adult↗