RESUMO
Perineural invasion (PNI) is a significant risk factor for cancer recurrence and metastasis; however, its mechanisms relating to cancer aggressiveness remain poorly understood. Here, we present a protocol for a non-surgical model of PNI in mice using a neurotropic melanoma cell line that migrates from the skin to the sciatic nerve. We describe the steps for cell culture and injection, tumor burden measurements, mouse euthanasia, and tissue dissection. We then detail procedures for sample cross-section and confocal imaging.
RESUMO
BACKGROUND: Biopsies of dysplastic nevi processed by bread-loafing allow for limited margin assessment; however, reported biopsy margins often influence management. OBJECTIVE: To evaluate the negative predictive value of biopsy margins of dysplastic nevi. METHODS: A retrospective search of a single academic institution's pathology database was conducted to identify all biopsy specimens of dysplastic nevi between January 1, 2015, and December 31, 2017. Biopsy specimen margin assessments were compared with excision pathology reports to calculate negative predictive value and to assess the frequency of residual nevus on excision after positive biopsy margins. RESULTS: A total of 1245 dysplastic nevi from 934 patients were identified. Clear biopsy margins had a negative predictive value for the absence of residual nevus on excision of 87.3% for dysplastic nevi of moderate atypia or greater. Residual nevus was identified on excision in 29.41% of cases of dysplastic nevi of moderate atypia or greater when initial biopsy margins were positive. LIMITATIONS: This was a retrospective, single-institution study. The calculations likely overestimate the true negative predictive value of biopsy margins because of processing of excision specimens by bread-loafing. CONCLUSIONS: This study provides additional evidence that reported biopsy margins are not representative of true margin status.
Assuntos
Síndrome do Nevo Displásico/patologia , Síndrome do Nevo Displásico/cirurgia , Neoplasias Cutâneas/patologia , Neoplasias Cutâneas/cirurgia , Centros Médicos Acadêmicos , Adulto , Biópsia por Agulha , Estudos de Coortes , Bases de Dados Factuais , Progressão da Doença , Feminino , Humanos , Imuno-Histoquímica , Masculino , Margens de Excisão , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Estudos Retrospectivos , Medição de Risco , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Pathologists sometimes include commentary on margin involvement in shave biopsy reports of keratinocyte carcinoma (KC). This practice can lead to confusion regarding the need for further treatment. There is limited literature evaluating the reliability of reported histologic margin status in shave biopsies of KC. OBJECTIVE: To evaluate the negative predictive value (NPV) of reported clear shave biopsy margins in basal and squamous cell carcinomas to determine whether this assessment is a reliable predictor of complete tumor removal. METHODS: A literature review was performed using the PubMed database. The data were compiled, NPVs were calculated by the tumor subgroup, and a statistical analysis was performed. RESULTS: Four studies met inclusion criteria. Two hundred twenty-one KCs were identified (n = 221). All specimens had negative-reported histologic margins (39 squamous cell carcinoma [SCC] and 182 BCC). Fifty-five cases initially noted to have negative margins on biopsy were found to have residual tumor on subsequent analysis: 5 SCC and 50 BCC, translating to 12.8% of all SCC (5/39) and 27.5% for BCC (50/182). Negative predictive values were found to be 75.1% for all KCs, 87.2% for SCC, and 72.5% for BCC. CONCLUSION: Negative histologic margin status on shave biopsy specimens of KC has a poor NPV and is an inadequate predictor for complete tumor removal.