RESUMO
Tricholemmoma, a benign follicular neoplasm with outer root sheath differentiation, typically comprises clear or pale cells, and when multiple is pathognomic of Cowden's syndrome. The tumor is probably underrecognized and in basaloid examples can be difficult to distinguish from basal cell carcinoma (BCC). We studied 55 tricholemmomas (including 15 basaloid cases) and compared immunohistochemical profile with nodular BCC from our archives. Basaloid and non-basaloid tricholemmomas had similar staining characteristics. BerEP4 was focally positive (range 10%-20%) in only 3/39 (7.7%) tricholemmomas compared with widespread positivity in BCC (90.8%, 139 of 151 cases with ≥50% tumor area stained). CD34 was expressed, usually focally (median 20%, range 10%-90%), in 52/53 (98.1%) tricholemmomas and was negative in all 21 BCCs stained. EMA staining lacked sensitivity or specificity in differentiating tricholemmoma from BCC. Five or more Merkel cells were found in 7/17 (40.1%) tricholemmomas and 1/23 (4.3%) nodular BCCs studied. In summary, immunohistochemistry is helpful in distinction between tricholemmoma, including difficult basaloid examples (BerEP4 negative or focal, CD34 positive) compared with BCC (BerEP4 widespread in most cases, CD34 negative). The presence of 5 or more Merkel cells is a relatively specific but not a particularly sensitive discriminator.
Assuntos
Biomarcadores Tumorais/análise , Carcinoma Basocelular/diagnóstico , Doenças do Cabelo/diagnóstico , Folículo Piloso/patologia , Neoplasias Cutâneas/diagnóstico , Antígenos CD34/análise , Antígenos CD34/biossíntese , Biomarcadores Tumorais/biossíntese , Diagnóstico Diferencial , HumanosRESUMO
The diagnostic difficulties of differentiating epithelial misplacement from invasive cancer in colorectal adenomatous polyps have been recognised for many years. Nevertheless, the introduction of population screening in the UK has resulted in extraordinary diagnostic problems. Larger sigmoid colonic adenomatous polyps, which are those most likely to show epithelial misplacement, are specifically selected into such screening programmes, because these polyps are likely to bleed and screening is based on the detection of occult blood. The diagnostic challenges associated with this particular phenomenon have necessitated the institution of an 'Expert Board': this is a review of the first five years of its practice, during which time 256 polyps from 249 patients have been assessed. Indeed, the Expert Board contains three pathologists, because those pathologists do not necessarily agree, and a consensus diagnosis is required to drive appropriate patient management. However, this study has shown substantial levels of agreement between the three Expert Board pathologists, whereby the ultimate diagnosis has been changed, from that of the original referral diagnosis, by the Expert Board for half of all the polyps, in the substantial majority from malignant to benign. In 3% of polyp cases, the Expert Board consensus has been the dual diagnosis of both epithelial misplacement and adenocarcinoma, further illustrating the diagnostic difficulties. The Expert Board of the Bowel Cancer Screening Programme in the UK represents a unique and successful development in response to an extraordinary diagnostic conundrum created by the particular characteristics of bowel cancer screening.
Assuntos
Adenocarcinoma/diagnóstico , Pólipos Adenomatosos/diagnóstico , Pólipos Adenomatosos/patologia , Pólipos do Colo/patologia , Neoplasias Colorretais/diagnóstico , Adenocarcinoma/patologia , Idoso , Pólipos do Colo/diagnóstico , Neoplasias Colorretais/patologia , Diagnóstico Diferencial , Detecção Precoce de Câncer , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeAssuntos
Adenocarcinoma/diagnóstico , Neoplasias da Mama/diagnóstico , Carcinoma de Apêndice Cutâneo/diagnóstico , Erros de Diagnóstico , Doenças do Cabelo/diagnóstico , Mamografia , Neoplasias da Mama/cirurgia , Diagnóstico Diferencial , Feminino , Doenças do Cabelo/cirurgia , Humanos , Programas de Rastreamento , Pessoa de Meia-IdadeRESUMO
Morphology at both cellular and glandular levels in the colon is dependent to an extent on cell-cell adhesion mediated by cadherin-catenin complexes. Alterations in the expression of E-cadherin, the cadherin normally present in colon, have been shown to be implicated in tissue remodelling within the gastrointestinal tract. Furthermore, it has previously been shown that P-cadherin, normally present only in stratified epithelia and placenta, is expressed in colitis and during neoplastic change in the colon. The morphological features of mucosal injury induced by pre-operative radiotherapy in the non-neoplastic rectal mucosa were studied in patients with rectal adenocarcinoma. Three characteristic phases of radiation proctitis were defined on histological grounds (acute injury, and early and late regenerative phases) essentially correlating with the time interval between radiotherapy and surgery; such features were mirrored by alterations in cadherin-catenin expression and localization in rectal crypts. On immunohistochemistry and western blotting, P-cadherin was highly expressed in the acute injury and early regenerative phases, with a decreased level of expression during late regeneration. E-cadherin and associated catenins were translocated from membrane to cytoplasm in degenerating crypts, with return of normal membranous expression in regenerating crypts. In conclusion, radiation-induced proctitis represents an in vivo model of mucosal injury and regeneration and provides a valid model in which to study events during epithelial injury and repair. Altered cadherin expression, in particular transient aberrant P-cadherin expression, is intimately associated with these processes.