RESUMO
Establishing the diagnosis of focal brain lesions in patients with unexplained neurologic symptoms represents a challenge. The goal of this study is to provide evidence supporting functional roles for CXC chemokine ligand (CXCL)13 and interleukin (IL)-10 in central nervous system (CNS) lymphomas and to evaluate the utility of each as prognostic and diagnostic biomarkers. We demonstrate for the first time that elevated CXCL13 concentration in cerebrospinal fluid (CSF) is prognostic and that CXCL13 and CXCL12 mediate chemotaxis of lymphoma cells isolated from CNS lymphoma lesions. Expression of the activated form of Janus kinase 1 supported a role for IL-10 in prosurvival signaling. We determined the concentration of CXCL13 and IL-10 in CSF of CNS lymphoma patients and control cohorts including inflammatory and degenerative neurologic disease in a multicenter study involving 220 patients. Bivariate elevated CXCL13 plus IL-10 was 99.3% specific for primary and secondary CNS lymphoma, with sensitivity significantly greater than reference standard CSF tests. These results identify CXCL13 and IL-10 as potentially important biomarkers of CNS lymphoma that merit further evaluation and support incorporation of CXCL13 and IL-10 into diagnostic algorithms for the workup of focal brain lesions in which lymphoma is a consideration.
Assuntos
Biomarcadores Tumorais/líquido cefalorraquidiano , Neoplasias do Sistema Nervoso Central/diagnóstico , Quimiocina CXCL13/líquido cefalorraquidiano , Interleucina-10/líquido cefalorraquidiano , Linfoma/diagnóstico , Recidiva Local de Neoplasia/diagnóstico , Adulto , Animais , Biomarcadores Tumorais/genética , Western Blotting , Estudos de Casos e Controles , Neoplasias do Sistema Nervoso Central/líquido cefalorraquidiano , Neoplasias do Sistema Nervoso Central/mortalidade , Quimiocina CXCL13/genética , Quimiotaxia , Feminino , Perfilação da Expressão Gênica , Humanos , Técnicas Imunoenzimáticas , Interleucina-10/genética , Linfoma/líquido cefalorraquidiano , Linfoma/mortalidade , Masculino , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Pessoa de Meia-Idade , Recidiva Local de Neoplasia/líquido cefalorraquidiano , Recidiva Local de Neoplasia/mortalidade , Prognóstico , RNA Mensageiro/genética , Reação em Cadeia da Polimerase em Tempo Real , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Taxa de Sobrevida , Células Tumorais CultivadasRESUMO
OBJECTIVE: Our goal was to determine the incidence and outcomes of intramammary in-transit sentinel lymph nodes (IMSLN) from primary malignant melanoma (MM) of the trunk. We hypothesize that regional metastasis to the breast from anterior trunk MM also occurs via the lymphatic system to these intramammary in-transit sentinel lymph nodes. BACKGROUND: MM is the most common solid tumor metastasis to the breast. The mechanism of intramammary (IM) metastasis is generally attributed to hematogenous rather than lymphatic spread. METHODS: We retrospectively reviewed medical records from all patients who underwent selective sentinel lymph node dissection at the UCSF Melanoma Center from 1993 to 2008 after the approval of UCSF Committee on Human Research. Of the 1911 cases, we found 614 patients with primary MM located on the trunk, and queried their medical records for in-transit SLN and SLNs in the breast. Data from preoperative lymphoscintigraphy, intraoperative lymphatic mapping, operative notes, and pathology and clinic notes were gathered. RESULTS: Of the 1911 patients with MM, 169 (8.9%) and 420 (22.0%) had anterior and posterior trunk lesions, respectively, and 25 patients (1.3%) with flank lesions (lateral abdominal wall below the rib cage, above the iliac crest). Of the anterior trunk population, 18 patients had in-transit SLNs. The vast majority of these patients (14 of 18, 77.8%) had in-transit IMSLN. Of patients with posterior trunk melanoma, 27 patients had in-transit nodes with 1 patient having IMSLNs. Of patients with flank melanomas, 3 patients had in-transit nodes with 1 patient having IMSLNs. Interestingly, all patients with IMSLNs had primary lesions located inferior to the breasts. Two of the 16 patients with IMSLNs had micrometastasis to IMSLN; 1 patient died and the other currently is disease free 4 years after initial SLND. Four of the 32 patients with non-IM in-transit nodes had micrometastases to these in-transit nodes. Of all patients with trunk melanomas, 4 patients had micrometastases to axillary SLNs (AxSLNs). Three of the 4 patients with positive AxSLNs also had positive in-transit nodes whereas only half of the patients with positive in-transit SLNs had positive AxSLNs. CONCLUSIONS: IMSLNs exist in the breast. Our results establish an anatomic basis for lymphatic metastasis to the breast from primary cutaneous melanoma mainly from the anterior trunk inferior to the breasts. For anterior trunk melanomas, IMSLNs should not be overlooked during SLND as they may harbor micrometastasis.
Assuntos
Neoplasias da Mama/patologia , Neoplasias da Mama/secundário , Melanoma/patologia , Melanoma/secundário , Biópsia de Linfonodo Sentinela , Neoplasias Cutâneas/patologia , Neoplasias Torácicas/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias da Mama/cirurgia , Feminino , Humanos , Excisão de Linfonodo , Linfonodos/patologia , Linfocintigrafia , Masculino , Melanoma/cirurgia , Pessoa de Meia-Idade , Células Neoplásicas Circulantes , Estudos Retrospectivos , Neoplasias Cutâneas/cirurgia , Neoplasias Torácicas/cirurgiaRESUMO
PURPOSE: The prospect for advances in the treatment of patients with primary central nervous system lymphoma (PCNSL) is likely dependent on the systematic evaluation of its pathobiology. Animal models of PCNSL are needed to facilitate the analysis of its molecular pathogenesis and for the efficient evaluation of novel therapeutics. EXPERIMENTAL DESIGN: We characterized the molecular pathology of CNS lymphoma tumors generated by the intracerebral implantation of Raji B lymphoma cells in athymic mice. Lymphoma cells were modified for bioluminescence imaging to facilitate monitoring of tumor growth and response to therapy. In parallel, we identified molecular features of lymphoma xenograft histopathology that are evident in human PCNSL specimens. RESULTS: Intracerebral Raji tumors were determined to faithfully reflect the molecular pathogenesis of PCNSL, including the predominant immunophenotypic state of differentiation of lymphoma cells and their reactive microenvironment. We show the expression of interleukin-4 by Raji and other B lymphoma cell lines in vitro and by Raji tumors in vivo and provide evidence for a role of this cytokine in the M2 polarization of lymphoma macrophages both in the murine model and in diagnostic specimens of human PCNSL. CONCLUSION: Intracerebral implantation of Raji cells results in a reproducible and invasive xenograft model, which recapitulates the histopathology and molecular features of PCNSL, and is suitable for preclinical testing of novel agents. We also show for the first time the feasibility and accuracy of tumor bioluminescence in the monitoring of a highly infiltrative brain tumor.
Assuntos
Neoplasias Encefálicas/patologia , Linfoma/patologia , Animais , Neoplasias Encefálicas/tratamento farmacológico , Neoplasias Encefálicas/imunologia , Polaridade Celular , Metilases de Modificação do DNA/genética , Enzimas Reparadoras do DNA/genética , Dacarbazina/análogos & derivados , Dacarbazina/uso terapêutico , Humanos , Interleucina-4/genética , Medições Luminescentes , Linfoma/tratamento farmacológico , Linfoma/imunologia , Macrófagos/fisiologia , Camundongos , Camundongos Nus , Fator de Transcrição STAT6/metabolismo , Temozolomida , Proteínas Supressoras de Tumor/genéticaRESUMO
BACKGROUND: The optimal therapeutic approach for patients with AIDS-related primary central nervous system lymphoma (AR-PCNSL) remains undefined. While its incidence declined substantially with combination antiretroviral therapy (cART), AR-PCNSL remains a highly aggressive neoplasm for which whole brain radiotherapy (WBRT) is considered a standard first-line intervention. METHODS: To identify therapy-related factors associated with favorable survival, we first retrospectively analyzed outcomes of AR-PCNSL patients treated at San Francisco General Hospital, a public hospital with a long history of dedicated care for patients with HIV and AIDS-related malignancies. Results were validated in a retrospective, multicenter analysis that evaluated all newly diagnosed patients with AR-PCNSL treated with cART plus high-dose methotrexate (HD-MTX). RESULTS: We provide evidence that CD4+ reconstitution with cART administered during HD-MTX correlates with long-term survival among patients with CD4 <100. This was confirmed in a multicenter analysis which demonstrated that integration of cART regimens with HD-MTX was generally well tolerated and resulted in longer progression-free survival than other treatments. No profound differences in immunophenotype were identified in an analysis of AR-PCNSL tumors that arose in the pre- versus post-cART eras. However, we detected evidence for a demographic shift, as the proportion of minority patients with AR-PCNSL increased since advent of cART. CONCLUSION: Long-term disease-free survival can be achieved in AR-PCNSL, even among those with histories of opportunistic infections, limited access to health care, and medical non-adherence. Given this, as well as the long-term toxicities of WBRT, we recommend that integration of cART plus first-line HD-MTX be considered for all patients with AR-PCNSL.
Assuntos
Antirretrovirais/uso terapêutico , Neoplasias do Sistema Nervoso Central/mortalidade , Irradiação Craniana , Linfoma Relacionado a AIDS/mortalidade , Metotrexato/uso terapêutico , Adulto , Idoso , Antimetabólitos Antineoplásicos/uso terapêutico , Neoplasias do Sistema Nervoso Central/patologia , Neoplasias do Sistema Nervoso Central/terapia , Terapia Combinada , Feminino , Seguimentos , Humanos , Linfoma Relacionado a AIDS/patologia , Linfoma Relacionado a AIDS/terapia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Prognóstico , Estudos Retrospectivos , Taxa de SobrevidaRESUMO
Genomic abnormalities at 348 loci encoding genes that may contribute to lung cancer transformation and progression were assessed using array comparative genomic hybridization in 21 squamous carcinomas (SqCas) and 16 adenocarcinomas (AdCas). Hierarchical clustering showed a clear pattern of gains and losses for the SqCas, whereas the pattern for AdCas was less distinct. Cross-validated classification using a K-nearest-neighbor assigned, on average, 32 of 37 samples to their proper histological subtype. The most noticeable differences between SqCas and AdCas were gain of chromosome 3q22-q26 and loss of chromosome 3p. These occurred almost exclusively in SqCas. The region of recurrent increase is approximately 30 Mb in extent, ranging from EVI1 to TFRC. PIK3CA, the alpha catalytic subunit of phosphatidylinositol 3-kinase (PI3K), is in this region. The PIK3CA copy number increase was validated using fluorescence in situ hybridization to lung cancer tissue microarrays. Activity of the downstream PI3K effector protein kinase B (PKB) was higher in SqCas than in AdCas and was correlated with PIK3CA copy number (r = 0.75), suggesting that these copy number increases contribute to activation of PI3K signaling in SqCas of the lung.
Assuntos
Carcinoma Pulmonar de Células não Pequenas/genética , Neoplasias Pulmonares/genética , Fosfatidilinositol 3-Quinases/genética , Adenocarcinoma/enzimologia , Adenocarcinoma/genética , Carcinoma Pulmonar de Células não Pequenas/enzimologia , Carcinoma de Células Escamosas/enzimologia , Carcinoma de Células Escamosas/genética , Feminino , Dosagem de Genes , Humanos , Neoplasias Pulmonares/enzimologia , Masculino , Hibridização de Ácido Nucleico , Análise de Sequência com Séries de Oligonucleotídeos , Fosfatidilinositol 3-Quinases/fisiologia , Transdução de Sinais/genéticaRESUMO
The Id (inhibitor of DNA binding) proteins are a family of helix-loop-helix (HLH) proteins (Id1, Id2, Id3, and Id4) that lack the basic domain necessary for DNA binding. The Id1 protein enhances cell proliferation and inhibits cellular differentiation in a variety of cell types. We have previously demonstrated that the Id1 gene is up-regulated in papillary and medullary thyroid cancers. In this study we characterized the expression and distribution of the Id1 protein in normal, hyperplastic, and neoplastic human thyroid tissue. We also evaluated the effect of the Id1 gene on thyroid cancer cell growth and markers of thyroid cell differentiation. We used semiquantitative immunohistochemistry to characterize Id1 protein expression in normal, hyperplastic (multinodular goiter and Graves' disease), and neoplastic thyroid tissue from 103 patients. Normal thyroid tissue had the lowest level of Id1 protein expression (P < 0.0001). Anaplastic thyroid cancer had the highest level (vs. benign and malignant thyroid tissues, P < 0.01). Id1 protein expression was higher in malignant thyroid tissue than in hyperplastic thyroid tissue (P < 0.02). We found no significant association between the level of Id1 protein expression and patient age, sex, tumor-node-metastasis stage, tumor size, primary tumor vs. lymph node metastasis, primary tumor vs. recurrent tumors, and extent of tumor differentiation. Inhibiting Id1 mRNA expression in thyroid cancer cell lines using Id1 antisense oligonucleotides resulted in growth inhibition (P < 0.03) and decreased thyroglobulin and sodium-iodine symporter mRNA expression (P < 0.02). In conclusion, Id1 is overexpressed in hyperplastic and neoplastic thyroid tissue and directly regulates the growth of thyroid cancer cells of follicular cell origin, but is not a marker of aggressive phenotype in differentiated thyroid cancer.
Assuntos
Bócio Nodular/metabolismo , Bócio Nodular/patologia , Doença de Graves/metabolismo , Doença de Graves/patologia , Proteínas Repressoras/metabolismo , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia , Fatores de Transcrição/metabolismo , Adulto , Biomarcadores/metabolismo , Diferenciação Celular , Divisão Celular , Linhagem Celular Tumoral , Feminino , Expressão Gênica , Humanos , Imuno-Histoquímica , Proteína 1 Inibidora de Diferenciação , Masculino , Pessoa de Meia-Idade , Proteínas Repressoras/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Distribuição Tecidual , Fatores de Transcrição/genética , Regulação para CimaRESUMO
BACKGROUND: Members of the Id helix-loop-helix proteins are key regulators of cell growth and differentiation in a variety of cell types. They are also required for cell cycle progression and regulate tumor angiogenesis. Furthermore, deregulated expression of Id proteins has been observed in some human malignancies. Therefore we hypothesized that the Id-1 gene may play a role in papillary thyroid carcinogenesis. METHODS: Id-1 gene expression was characterized by Northern blot analysis and Id-1 immunohistochemistry in human thyroid tissue. Id-1 gene expression and regulation was evaluated in a human papillary thyroid cancer cell line, TPC-1, by Northern blot analysis. RESULTS: The Id-1 gene was significantly overexpressed in papillary thyroid cancer compared with normal thyroid tissue from the same patients (n = 18) by both Northern blot analysis and semiquantitative Id-1 immunohistochemistry (P <.001). Id-1 immunoreactivity was primarily localized to the cytoplasm of the thyroid follicular cells. In the TPC-1 cell line, stimulation by TSH and serum up-regulated Id-1 mRNA expression 1.5- and 4.0-fold, respectively. Activation of the mitogen intracellular protein kinase A and protein kinase C signaling pathways also up-regulated Id-1 mRNA expression. Inhibition of Id-1 mRNA expression with Id-1 antisense oligonucleotide inhibited growth compared with control Id-1 sense and random oligonucleotides (P <.05). CONCLUSIONS: The Id-1 gene is overexpressed in papillary thyroid cancer. Id-1 may play a role in the regulation of growth in papillary thyroid cancer.
Assuntos
Carcinoma Papilar/metabolismo , Carcinoma Papilar/patologia , Proteínas Repressoras , Neoplasias da Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/patologia , Fatores de Transcrição/metabolismo , Northern Blotting , Carcinoma Papilar/genética , Expressão Gênica , Humanos , Imuno-Histoquímica , Proteína 1 Inibidora de Diferenciação , Estrutura Terciária de Proteína , Glândula Tireoide/metabolismo , Neoplasias da Glândula Tireoide/genética , Distribuição Tecidual , Fatores de Transcrição/química , Fatores de Transcrição/genética , Células Tumorais CultivadasAssuntos
Metástase Linfática/diagnóstico , Biópsia de Linfonodo Sentinela/métodos , Biomarcadores Tumorais/análise , Neoplasias da Mama/química , Neoplasias da Mama/patologia , Carcinoma/química , Carcinoma/diagnóstico , Carcinoma/secundário , Intervalo Livre de Doença , Reações Falso-Negativas , Feminino , Previsões , Humanos , Técnicas Imunoenzimáticas , Metástase Linfática/diagnóstico por imagem , Melanoma/química , Melanoma/diagnóstico , Melanoma/secundário , Reação em Cadeia da Polimerase , Valor Preditivo dos Testes , Cintilografia , Tamanho da Amostra , Coloração e Rotulagem/métodosRESUMO
Recent evidence suggests that there is etiologic heterogeneity among the various subtypes of lymphoid neoplasms. However, epidemiologic analyses by disease subtype have proven challenging due to the numerous clinical and pathologic schemes used to classify lymphomas and lymphoid leukemias over the last several decades. On behalf of the International Lymphoma Epidemiology Consortium (InterLymph) Pathology Working Group, we present a proposed nested classification of lymphoid neoplasms to facilitate the analysis of lymphoid neoplasm subtypes in epidemiologic research. The proposed classification is based on the World Health Organization classification of lymphoid neoplasms and the International Classification of Diseases-Oncology, Third Edition (ICD-O-3). We also provide a translation into the proposed classification from previous classifications, including the Working Formulation, Revised European-American Lymphoma (REAL) classification, and ICD-O-2. We recommend that epidemiologic studies include analyses by lymphoma subtype to the most detailed extent allowable by sample size. The standardization of groupings for epidemiologic research of lymphoma subtypes is essential for comparing subtype-specific reports in the literature, harmonizing cases within a single study diagnosed using different systems, as well as combining data from multiple studies for the purpose of pooled analysis or meta-analysis, and will probably prove to be critical for elucidating etiologies of the various lymphoid neoplasms.
Assuntos
Linfoma/classificação , Linfoma/epidemiologia , Europa (Continente)/epidemiologia , Doença de Hodgkin/classificação , Doença de Hodgkin/epidemiologia , Humanos , Linfoma/patologia , Linfoma não Hodgkin/classificação , Linfoma não Hodgkin/epidemiologia , América do Norte/epidemiologia , Reprodutibilidade dos TestesAssuntos
Antineoplásicos/uso terapêutico , Neoplasias Oculares/tratamento farmacológico , Linfoma Difuso de Grandes Células B/tratamento farmacológico , Talidomida/análogos & derivados , Neoplasias Oculares/patologia , Feminino , Humanos , Lenalidomida , Linfoma Difuso de Grandes Células B/patologia , Pessoa de Meia-Idade , Talidomida/uso terapêuticoRESUMO
Selective sentinel lymphadenectomy (SSL) following preoperative lymphoscintigraphy is the most significant recent advance in the management of patients with primary melanoma. This study evaluates the prognostic value of sentinel lymph node (SLN) status and other risk factors in predicting survival and recurrence in patients with primary cutaneous melanoma. From October 1993 to July 1998 a series of 412 patients with primary invasive melanoma underwent SSL at the UCSF/ Mt. Zion Melanoma Center. The outcome of 363 evaluable patients is summarized in this study. The factors related to survival and disease recurrence were analyzed by Cox proportional hazard regression models. The overall incidence of patients with positive SLNs was 18%. Over a median follow-up of 4.8 years, the overall mortality rate in patients with primary cutaneous melanoma was 18.7%, and 74 recurrences occurred (20.4%). Mortality was significantly related to SLN status [HR = 2.06; 95% Confidence interval (CI) 1.18, 3.58], angiolymphatic invasion (HR = 2.21; 95% CI 1.08, 4.55), ulceration (HR = 1.79; 95% CI 1.02, 3.15), mitotic index (HR =1.38; 95% CI 1.01, 1.90), and tumor thickness (HR = 2.20, 95% CI 1.21, 3.99). Factors significantly related to disease-free survival included SLN status (HR = 2.09; 95% CI 1.31, 3.34), tumor thickness (HR = 1.89; 95%. CI 1.20,2.98), and age (HR= 1.26 95% CI 1.08, 1.47). SLN status was the most significant factor for melanoma recurrence and death. Other important predictors include tumor thickness, ulceration, lymphatic invasion, and mitotic index.
Assuntos
Melanoma/mortalidade , Melanoma/secundário , Recidiva Local de Neoplasia/etiologia , Recidiva Local de Neoplasia/mortalidade , Neoplasias Cutâneas/mortalidade , Neoplasias Cutâneas/patologia , Adulto , Idoso , Feminino , Seguimentos , Humanos , Metástase Linfática , Masculino , Melanoma/cirurgia , Pessoa de Meia-Idade , Prognóstico , Fatores de Risco , Biópsia de Linfonodo Sentinela , Neoplasias Cutâneas/cirurgia , Taxa de Sobrevida , Fatores de TempoRESUMO
BACKGROUND: Previous studies have shown conflicting results regarding the expression of c-Erb-B2 in malignant mesothelioma. Overexpression of the c-erb-B2 gene product in a subset of mesothelioma may have prognostic or therapeutic implications. OBJECTIVE: To determine whether malignant mesothelioma demonstrates c-Erb-B2 overexpression and, if so, whether such overexpression correlates with gene amplification. METHODS: Immunohistochemistry, reverse transcription-polymerase chain reaction, and fluorescent in situ hybridization were used to analyze archived tissue from 37 cases of malignant mesothelioma. RESULTS: Although immunohistochemical staining for c-Erb-B2 was detected in most mesotheliomas, the staining was cytoplasmic and was not consistent between the 2 different primary antibodies used. Moreover, even cases with strong cytoplasmic staining for c-Erb-B2 did not demonstrate increased messenger RNA levels or gene copy numbers compared to cases that demonstrated no staining. CONCLUSIONS: Cytoplasmic immunoreactivity for c-Erb-B2 in mesothelioma does not represent gene overexpression or amplification and may be an immunohistochemical artifact.
Assuntos
Citoplasma/química , Amplificação de Genes/genética , Regulação Neoplásica da Expressão Gênica/genética , Mesotelioma/genética , Receptor ErbB-2/análise , Anticorpos Monoclonais/metabolismo , Anticorpos Monoclonais Humanizados , Artefatos , Citoplasma/patologia , Dosagem de Genes , Genes erbB-2/genética , Humanos , Imuno-Histoquímica , Mesotelioma/química , Mesotelioma/patologia , Prognóstico , Receptor ErbB-2/imunologia , Estudos Retrospectivos , Coloração e Rotulagem , TrastuzumabRESUMO
Overexpression of KIT protein (CD117), the product of the c-kit gene, has been shown to have important prognostic and therapeutic implications for a number of malignant neoplasms. Previous studies have shown conflicting results regarding the expression of c-kit in malignant mesothelioma. To determine whether malignant mesothelioma expresses KIT, immunohistochemistry and RT-PCR were used to analyze archived tissue from 37 cases of mesothelioma. Although a subset of mesotheliomas demonstrated specific staining with the DAKO anti-KIT antibody, in each case staining was nuclear. We could not detect c-kit mRNA by a sensitive RT-PCR assay, even in cases with strong nuclear staining. Furthermore, a second anti-KIT antibody (Cell-Marque) only demonstrated staining in a single mesothelioma case and in none of the cases that demonstrated nuclear staining. We conclude that immunoreactivity for KIT in mesothelioma does not represent expression of the c-kit gene and may represent antibody cross-reaction with nuclear proteins. Our results raise doubt about previously reported expression of KIT in mesothelioma and consequently, the applicability of therapeutic agents that target the kinase activity of KIT.
Assuntos
Biomarcadores Tumorais/análise , Mesotelioma/metabolismo , Neoplasias Pleurais/metabolismo , Proteínas Proto-Oncogênicas c-kit/biossíntese , Reações Cruzadas , Reações Falso-Positivas , Humanos , Imuno-Histoquímica , Mesotelioma/patologia , Neoplasias Pleurais/patologia , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
Selective sentinel lymphadenectomy dissection has been demonstrated to have high predictive value for axillary staging in breast cancer patients. Preoperative lymphoscintigraphy can localize and facilitate the harvesting of sentinel lymph nodes (SNLs) with a high success rate. The failure rate of selective sentinel lymphadenectomy ranges between 2% and 8%. Details of the failures were seldom addressed. This study analyzes the causes of failure to harvest SLNs in spite of positive preoperative lymphoscintigraphy. From November 1997 through November 2000, 201 female patients with histologically confirmed and operable breast carcinoma underwent selective sentinel lymphadenectomy at the University of California, San Francisco (UCSF) Carol Franc Buck Breast Care Center. Among these patients, 183 (91%) received preoperative lymphoscintigraphy to identify axillary lymph nodes. The causes of failure to harvest the SLNs in this group of patients despite successful preoperative lymphoscintigraphy were analyzed. In our series, the failure rate of SLN identification was 7.0% (14/201). The failure rate for our first year was 11.1% (6/54), second year 9.1% (7/77), and third year 1.4% (1/70). The incidence of failure in spite of positive preoperative lymphoscintigraphy was 3.5% (6/170). The shine-through effect of the primary injection site and failure to visualize a blue lymph node were the main reasons for technical failure. Most of these cases occurred during our learning curve of the procedure. The possibility of failure to get the SLN should be explained to patients before surgery. Axillary lymph node dissection (ALND) should be done if selective SLN dissection is not successful.