The Diagnostic Performance of Magnetic Resonance Imaging in the Categorization of Pediatric Neck Lymph Nodes: Radiologic and Pathologic Correlations.

BACKGROUND/AIM: To present MRI features of neck lymph nodes in benign and malignant conditions in the pediatric population. MATERIALS AND METHODS: MRIs of the neck of 51 patients 1 to 18 years old (40 boys, 11 girls [10.08±4.73]) with lymph node biopsy were retrospectively analyzed. Those were grouped as benign including reactive (27 [52.9%]) and lymphadenitis (11 [21.6%]), and malignant (13 [25.5%]). The groups were evaluated multiparametrically in terms of quantitative and qualitative variables. RESULTS: The long axis, short axis, area, and apparent diffusion coefficient (ADC) values of the largest lymph node were 21 (17 to 24) mm, 14 (12 to 18) mm, 228.60 (144.79 to 351.82) mm 2 , 2531 (2457 to 2714) mm 2 /s for reactive, 24 (19 to 27) mm, 15 (11 to 20) mm, 271.80 (231.43 to 412.20) mm 2 , 2534 (2425 to 2594) mm 2 /s for lymphadenitis, 27 (23.50 to 31.50) mm, 20 (15 to 22) mm, 377.08 (260.47 to 530.94) mm 2 , 2337 (2254 to 2466) mm 2 /s for malignant, respectively. Statistical analysis of our data suggests that the following parameters are associated with a higher likelihood of malignancy: long axis >22 mm, short axis >16 mm, area >319 cm 2 , ADC value <2367 mm 2 /s, and supraclavicular location. Perinodal and nodal heterogeneity, posterior cervical triangle location are common in lymphadenitis ( P <0.001). Reactive lymph nodes are distributed symmetrically in both neck halves ( P <0.001). CONCLUSION: In the MRI-based approach to lymph nodes, not only long axis, short axis, surface area, and ADC, but also location, distribution, perinodal, and nodal heterogeneity should be used.

The benefit of superb microvascular imaging and shear wave elastography in differentiating metastatic axillary lymphadenopathy from lymphadenitis.

PURPOSE: The purpose of this study is to detect and compare the diagnostic performances of vascularity index (VI) via superb microvascular imaging (SMI) and shear wave elastography (SWE) in metastatic axillary lymphadenopathy and lymphadenitis. MATERIALS AND METHODS: The study is based on 45 female patients who were ultrasonographed due to swelling in the axilla and underwent SWE and SMI before tru-cut biopsy, between August 2019 and February 2021. The patients had a total of 53 lymph nodes (LNs), 38 of these were metastatic and 15 were lymphadenitis. RESULTS: The results showed that mean volumes, value of cortex thickness, elasticity and velocity values, and mean VI values were significantly higher in metastatic LAP group compared to lymphadenitis group. Correlation analysis showed that both VI (r: 0.44) and elastography (r: 0.52) values were positively correlated with the cortex thickness, while elastography values were strongly correlated with volume (r: 0.42) and short diameter (r: 0.40). For differentiating lymphadenitis and metastatic LAP, the optimal cut-off VI value was 8.55 while the optimal cut-off elastography value was 31.8 kPa. CONCLUSION: In conclusion, combined grayscale ultrasonography evaluation of lymph nodes with SWE and SMI increase the diagnostic performance in distinguishing lymphadenitis-metastatic LAP.

Severe Fever with Thrombocytopenia Syndrome with Necrotizing Lymphadenitis in a Patient who Underwent 18F-FDG PET/CT: A Case Report.

Severe fever with thrombocytopenia syndrome (SFTS), also known as fever, thrombocytopenia, and leukopenia syndrome, is an emerging tick-borne infectious disease in Asian countries. SFTS should be suspected in patients presenting with fever, thrombocytopenia, and leukopenia and have a history of tick exposure in an endemic area. Since SFTS can be accompanied by lymphadenopathy, particularly generalized lymphadenopathy, it can be confused with a primary malignancy, such as lymphoma. The study reports a case of SFTS accompanied by multiple lymphadenopathies, which mimicked malignant lymphoma on F-18 fluorodeoxyglucose positron emission tomography/computed tomography.

Angioimmunoblastic T-cell lymphoma masquerading as granulomatous lymphadenitis: Fine needle aspiration cytology, clinical and radiology correlation.

Fine needle aspiration (FNA) is a minimally invasive technique used in the initial diagnosis of superficial lesions, including lymphadenopathy. Its benefit in lymph node pathology, however, is highly variable, especially in heterogeneous lymphoproliferative disorders like angioimmunoblastic T-cell lymphoma (AITL). AITL is an aggressive hematopoietic malignancy, histologically characterized by medium-sized neoplastic cells, high endothelial venule proliferations, and a heterogeneous hematolymphoid background. Diagnostic difficulty arises at lymph node FNA, where cytology yields nonspecific polymorphous collections of medium-sized lymphocytes, hematolymphoid cells, dendritic cell-lymphoid complexes, and lymphoid tissue fragments with transgressing blood vessels; findings mimicking reactive lymphadenopathy. We present a case of a 62-year-old male who presented with cervical lymphadenopathy. Neck level II lymph node FNA revealed granulomatous inflammation. A cell block was prepared for additional infectious studies but was non-contributory due to lack of material. Flow cytometry showed no evidence of non-Hodgkin lymphoma. Excisional biopsy revealed lymph node effacement by a T-cell lymphoproliferative disorder consistent with AITL. This case contributes to the paucity of literature regarding the cytologic features of AITL observed at FNA, and becomes the premier case to emphasize the addition of granulomatous features. Despite the aggressive nature of this entity, cases are frequently misdiagnosed as reactive on initial evaluation resulting in delay of treatment. This report serves to raise suspicion of AITL and other polymorphic cellular lymphomas in the setting of reactive granulomatous cytomorphology, thus prompting histological examination of tissue biopsy, expediting treatment, and ultimately providing potential improvement to the current prognosis.

Diagnostic performance of EBUS-TBNA and its interrelation with PET-CT in patients with extra-thoracic malignancies.

INTRODUCTION: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) is a well-established diagnostic tool for lung cancer, sarcoidosis, and suspected metastatic extra-thoracic malignancy (ETM). Patients with primary ETM often have hypermetabolic mediastinal/hilar lymph node enlargement in the PET-scan done for initial staging or post treatment followup. We aimed to determine the diagnostic performance of EBUS-TBNA and the relationship between PET-SUV values and diagnosis of malignancy metastasis in patients with ETM. MATERIALS AND METHODS: Results of EBUS-TBNA in ETM patients with suspected MLN metastasis were retrospectively analysed (May 2016 to July 2019). Non-malign results were confirmed for surgery or clinical/radiological followup. Lymph nodes with a high FDG-uptake (SUV > 2.5, MLN) were reported as suspicious for metastasis. RESULT: Of the 588 EBUS procedures, 109 were included in the analysis. Patient' mean age was 62.5 ± 10.1 years; there were 35 men and 74 women. Primary malignancies were breast cancer in 33, gastrointestinal in 23, female genital tract in 17, head and neck in 14, genitourinary cancer in 13, malignant melanoma in 6, sarcoma in 2 and kaposi sarcoma in 1. According to EBUS-TBNA smear and cell block histopathologic evaluations, 16 patients' results (14.7%) were malignant compatible with metastasis of ETM. Among the 93 patients with non-malignant diagnosis, EBUS-TBNA revealed a granulomatous lympadenitis compatible with sarcoid reaction in 7 and tuberculosis in 2. A total of 9 patients underwent surgical procedures after EBUSTBNA, with a definitive histological diagnosis of granulomatous lymphadenitis in 2, malignancy in 5 and, reactive lymph node in 2. Overall sensitivity, specificity, positive predictive value, negative predictive value and diagnostic accuracy of EBUS-TBNA were 76.19% (95% CI 52.83-91.78), 100% (95% CI 95.89-100.00), 100%, 94.62% (95% CI 89.12-97.12) and 95.4%, respectively. CONCLUSIONS: EBUS-TBNA sampling has high diagnostic performance. Histopathological confirmation requirement for MLN should be kept in mind in patients with ETM, even they have negative EBUS results.

Cervicofacial non-tuberculous mycobacterial lymphadenitis: clinical determinants of incomplete surgical removal.

In patients with non-tuberculous mycobacterial cervicofacial lymphadenitis, incomplete surgical removal of infected lymph nodes leads to delayed healing and a higher recurrence rate, with eventual spontaneous drainage through the skin. However, complete surgical removal is not always achievable due to the extent of the infected tissue and proximity to vulnerable structures, such as the facial or accessory nerve. The aim of this study was to identify the clinical determinants of the (in)ability to perform complete surgical removal. The electronic health records of patients aged 0-15 years with bacteriologically proven non-tuberculous mycobacterial cervicofacial lymphadenitis, who underwent surgical treatment and preoperative sonographic imaging, were analysed. This was a case-control study. A total of 103 patients met the inclusion criteria. Most of the infections were unilateral, submandibular, and caused by Mycobacterium avium. Multiple logistic regression analysis revealed that higher age (odds ratio 1.24, 95% confidence interval 1.04-1.47) and fistulization (odds ratio 3.15, 95% confidence interval 1.13-8.75) were significantly associated with a limited ability to surgically remove all infected tissue. However, a larger sonographic lymph node size was not significantly associated. These findings could aid clinicians when informing the parent(s)/guardian(s) of the patient preoperatively and in properly estimating the intraoperative and postoperative course.

[Cervical lymphadenitis caused by non-tuberculous mycobacteria in children with different residence]. / Zervikale Lymphadenitis durch atypische Mykobakterien bei Kindern mit unterschiedlichem Wohnsitz.

OBJECTIVE: Atypical mycobacteria form a heterogeneous group. Although more than 140 species have been identified, only 25 of them are considered responsible for infection in humans. The most frequent manifestation of the disease in immunocompetent children is the cervical lymphadenitis. Aims of this study were to identify a correlation of the location of residence with patients' demographics and disease characteristics, to evaluate the ultrasonographic findings and the different operative treatments modalities and to develop an algorithm for the diagnosis and treatment. MATERIALS AND METHODS: Cases were identified by using the hospital's correspondence, microbiology and pathology databases. Demographic and clinical data were collected. A statistical analysis of the results was performed. RESULTS: 32 patients were included. Our data revealed no significant correlation between area of residence and disease characteristics. Hypoechoic lymph nodes with intraglandular necrosis and low vascularity were observed in the majority of patients. Surgical treatment included abscess incision with biopsy, lymphadenectomy, selective neck dissection and partial parotidectomy. A recurrent disease was significantly more frequent after abscess incision. CONCLUSIONS: Further studies with prospective design are required, in order to confidently identify the correlation between area of residence and disease characteristics. Similar ultrasonographic findings suggest a constant constellation of changes that facilitate diagnostic evaluation. Complete surgical excision offers an effective management option as it combines definitive treatment and histological confirmation with low risk of complications.

Cervical lymphadenopathy in children: a diagnostic tree analysis model based on ultrasonographic and clinical findings.

OBJECTIVES: To establish a diagnostic tree analysis (DTA) model based on ultrasonography (US) findings and clinical characteristics for differential diagnosis of common causes of cervical lymphadenopathy in children. METHODS: A total of 242 patients (131 boys, 111 girls; mean age, 11.2 ± 0.3 years; range, 1 month-18 years) with pathologically confirmed Kikuchi disease (n = 127), reactive hyperplasia (n = 64), lymphoma (n = 24), or suppurative lymphadenitis (n = 27) who underwent neck US were included. US images were retrospectively reviewed to assess lymph node (LN) characteristics, and clinical information was collected from patient records. DTA models were created using a classification and regression tree algorithm on the basis of US imaging and clinical findings. The patients were randomly divided into training (70%, 170/242) and validation (30%, 72/242) datasets to assess the diagnostic performance of the DTA models. RESULTS: In the DTA model based on all predictors, perinodal fat hyperechogenicity, LN echogenicity, and short diameter of the largest LN were significant predictors for differential diagnosis of cervical lymphadenopathy (overall accuracy, 85.3% and 83.3% in the training and validation datasets). In the model based on categorical parameters alone, perinodal fat hyperechogenicity, LN echogenicity, and loss of fatty hilum were significant predictors (overall accuracy, 84.7% and 86.1% in the training and validation datasets). CONCLUSIONS: Perinodal fat hyperechogenicity, heterogeneous echotexture, short diameter of the largest LN, and loss of fatty hilum were significant US findings in the DTA for differential diagnosis of cervical lymphadenopathy in children. KEY POINTS: • Diagnostic tree analysis model based on ultrasonography and clinical findings would be helpful in differential diagnosis of pediatric cervical lymphadenopathy. • Significant predictors were perinodal fat hyperechogenicity, heterogeneous echotexture, short diameter of the largest LN, and loss of fatty hilum.

Unilateral acute cervical lymphadenitis in children: can we predict the need for surgery?

INTRODUCTION: Paediatric acute cervical lymphadenitis is a frequent diagnosis in the emergency department. Traditionally, suppurative cervical lymphadenitis (SCL) is associated with a higher need of surgical drainage. However, a great variability in the management of this suppurative infections can be observed. Moreover, the clinical distinction between non-suppurative cervical lymphadenitis (NSCL) and SCL is not an easy task and there are, currently, no guidelines defining which patients are eligible for imaging study. OBJECTIVES: To assess the determinants and benefits in the surgical management of SCL in children. As secondary outcome, to determine differences in epidemiological characteristics, clinical, biochemical and radiological features between NSCL and SCL. MATERIAL AND METHODS: A retrospective survey was carried out in a tertiary university hospital between January 2007 and December 2016. Forty-two children with a diagnosis of acute cervical lymphadenitis (ACL) were included and categorized according to the presence of suppuration, resulting in two groups: NSCL and SCL. The latter group was further categorized into surgical and non-surgical groups, according to the need of surgical drainage. RESULTS: No significant differences were found between SCL and NSCL groups in gender, age and previous antibiotics intake (p > 0.05). According to clinical presentation, odynophagia was significantly more frequent in NSCL patients (p = 0.01), with no differences found in other clinical parameters (p > 0.05). Patients presenting acute cervical lymphadenitis involving the submandibular region have 16 times the odds of a suppurative process (p = 0.029). In a SCL subgroup analysis, no association was observed between lymphadenitis size or location and the need for surgical drainage (p > 0.05). Children included in the SCL surgical group presented a trend to an increased in the hospitalization length (p = 0.01), when comparing to those in which treatment was limited to intravenous antibiotics. One death was observed in the SCL non-surgical group. CONCLUSIONS: Predictive factors for the need of surgery were not found. Furthermore, surgical drainage was not associated with better outcomes. Surgery could be considered in selected stable patients, when alternative medical treatments do not seem to work, in a case-to-case basis.

[Causes of mediastinal/hilar granulomatous lymphadenitis]. / Mediastinal/hiler granülomatöz lenfadenit etyolojisi.

INTRODUCTION: Granulomatous lung disease (GLD) is caused by a wide range of conditions and it is challenge for pulmonologist. A detailed history of exposures is fundamental in GDL and has been found pivotal to reach a precise diagnosis. MATERIALS AND METHODS: Between September 2014 and December 2016, the distribution of patients diagnosed with granulomatous lymphadenitis in the mediastinal/hilar lymph nodes by endobronchial ultrasound (EBUS) or mediastinoscopy was analyzed. To be listed as 'confident', a diagnosis of sarcoidosis required compatible histological, radiological and clinical findings in conjunction with negative cultures. Infectious entities listed as 'confident' had either microorganisms in tissue section, positive culture, positive serology or positive antigen detection in a consistent clinical pathological setting. RESULT: Granulomatous lymphadenitis was detected in 110 patients. The included 110 cases consisted of 70.9% women and median age of 53 (range 44-61) years. The final diagnosis of the patients was accepted to be sarcoidosis in 79 (71.8%), sarcoid like granulomas in 7 (6.4%), tuberculosis in 4 (3.6%), silicosis in 4 (3.6%), drug-associated granuloma in 2 (1.8%), hypersensitivity pneumonitis in 1 (0.9%), Chron disease in 1 (0.9%), unspecified in 12 (10.9%). Three patients were classified as tuberculosis based on culture. CONCLUSIONS: In this study, we found that the most common cause of granulomatous lymphadenitis was sarcoidosis. Contrary to expectations, the number of patients diagnosed with tuberculosis was very low.

Atypical presentation of cat scratch disease: Parinaud's oculoglandular syndrome with facial nerve paresis.

A 28-year-old man presented to our clinic over the course of 3 weeks with symptoms that progressed from mild headaches to fever, fatigue, myalgia and an enlarged right preauricular lymph node with ipsilateral conjunctivitis and upper eyelid weakness. Our differential included Epstein Barr Virus/Cytomegalovirus mononucleosis, bacterial conjunctivitis and lymphoma. We evaluated with CBC, EBV IgM Ab, lactate dehydrogenase level and a CMV IgG Ab which were all within normal limits. During his third visit, we discovered our patient had been scratched by two stray kittens he had adopted 2 months prior. We confirmed the diagnosis with a positive Bartonella henselae IgG level and diagnosed him with cat scratch disease presenting as Parinaud's oculoglandular syndrome. He was treated with a 5-day course of Azithromycin 250 mg with definitive improvement.

Diagnostic performances of superb microvascular imaging, shear wave elastography and shape index in pediatric lymph nodes categorization: a comparative study.

OBJECTIVE: To determine the diagnostic utility of a vascularity index via superb microvascular imaging in lymph nodes of children with malignant lymphoma and acute lymphadenitis compared to normal lymph nodes. METHODS: We performed a retrospective study for multiparametric lymph node (LN) evaluation. Malignant lymphoma diagnosed via histopathological examination and lymph nodes receiving an acute lymphadenitis diagnosis based on clinical and laboratory findings constituted the study subgroups. We calculated a shape index [SI (percent of shortest to longest diameter)] using grayscale ultrasonography and elasticity and velocity values via shear wave elastography (SWE) as well as a vascularity index (VI) using superb microvascular imaging (SMI) for comparison with normal lymph nodes. RESULTS: 45 lymph nodes diagnosed with malignant lymphoma, 72 lymph nodes diagnosed with acute lymphadenitis and 146 normal lymph nodes were evaluated. For differentiating lymphoma from normal lymph nodes, vascularity index cut-off values higher than 15% represented a diagnostic accuracy of 95%; cut-off elasticity values higher than 17 kPa exhibited a diagnostic accuracy of 99%. Optimal VI, elasticity, velocity and SI cut-off values in differentiating lymphoma from lymphadenitis were 15%, 17 kPa, 2.45 m sn-1 (p < 0.001) and 65% (p < 0.002) with calculated diagnostic accuracies of 83, 87, 88 and 68%, respectively. CONCLUSION: Vascularity index values obtained via superb microvascular imaging and SWE would be reasonably useful in differentiating malignant lymphoma and acute lymphadenitis from normal LNs. SWE would be more efficient in distinguishing malignant lymph nodes from acute lymphadenitis compared with superb microvascular imaging. Advances in knowledge: Vascularity index by superb microvascular imaging would be a novel Doppler parameter in differentiating both lymphoma from lymphadenitis and also lymphadenitis from normal lymph nodes.

Isolated Mediastinal Lymphadenopathy Caused by Rhodococcus equi Infection.

Mediastinal lymphadenopathy is common finding in thoracic surgery, and it often requires morphologic confirmation to establish the definitive diagnosis. The most frequent diagnoses are metastatic lung cancer, sarcoidosis, lymphoma, tuberculosis, and other causes of granulomatous infections. Rhodococcus equi is a rare pathogen in humans that mostly affects immunocompromised patients. This report presents a case with isolated mediastinal lymphadenopathy caused by Rhodococcus equi infection in a 71-year-old immunocompetent patient.

Utility of endobronchial ultrasound-guided transbronchial needle aspiration in diagnosing non-specific inflammatory intrathorcacic lymphadenitis.

BACKGROUND AND OBJECTIVE: Endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) has emerged as a minimally invasive technique for diagnosing intrathoracic malignancies and some benignancies; however, there are no data available on the utility of EBUS-TBNA for the diagnosis of non-specific inflammatory intrathoracic lymphadenitis. METHODS: A prospective analysis was performed from 104 patients with enlarged lymphadenopathy suspected of non-specific lymphadenitis referred for EBUS-TBNA between October 2009 and March 2012. Rapid on-site cytological evaluation was not adopted. Microbiological tests were carried out in all patients. Patients were excluded from the study if there was other diagnosis being defined. RESULTS: One hundred ninety-one lesions were aspirated in 94 patients with enlarged mediastinal/hilar lymph nodes within reach of EBUS-TBNA, which were diagnosed as non-specific intrathorcacic lymphadenitis by pathology and clinical follow-up. According to EBUS-TBNA pathologies, 94 patients were categorized into four kinds: (i) inflammatory cell infiltrates and/or noncaseating necrosis in 38 cases; (ii) granuloma formed by epithelioid cells and/or fiber hyperplasia in 13 cases; (iii) lymph node tissue/lymphocyte without obvious abnormal lesions in 41 cases; (iv) inadequate sample in 2 cases. Bacterial and/or fungal smears and cultures were carried out in all 94 patients (100%), with pathogens being found in 4 (4.3%) cases. All patients (100%) underwent acid-fast staining and culture for mycobacterium tuberculosis to exclude tuberculosis. No procedure-related complication was observed. CONCLUSIONS: EBUS-TBNA can provide pathological and microbiological evidences for diagnosing non-specific inflammatory intrathoracic lymphadenopathy, and it is a safe and effective first-line investigation for ruling out malignancies and other benign diseases.

Linfadenitis cervical por Salmonella no Typhi en una paciente diabética / Cervical lymphadenitis caused by no typhoid Salmonella in a diabetic patient

Resumen La infección por Salmonella no Typhi es una de las enfermedades transmitidas por alimentos más común y ampliamente extendida en el mundo. Aunque la mayoría de los casos se limitan al tracto gastrointestinal, el compromiso extraintestinal no es infrecuente. Sin embargo, la adenitis como manifestación aislada, es una forma inusual de presentación de la enfermedad. Comunicamos el caso clínico de una mujer de 67 años de edad con diagnóstico de diabetes mellitus y una linfadenitis cervical por Salmonella no Typhi tratada con ciprofloxacina y y que requirió resección quirúrgica.

No Typhoid Salmonella infection is one of the most common and widely spread foodborne diseases worldwide. Although most cases are limited to the gastrointestinal tract, extraintestinal involvement is not uncommon. However, adenitis as an isolated manifestation, is an unusual form of the disease. We report a case of Salmonella no Typhoid cervical lymphadenitis in a 67-year-old female with a recent diagnosis of diabetes mellitus, who was treated with surgery and ciprofloxacin.

Atypical Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis simulating lymphadenitis on 18F-FDG PET/CT and its differential diagnosis.

Diagnosis of Epstein-Barr virus-associated hemophagocytic lymphohistiocytosis (EBV-HLH) is challenging as its clinical presentation is atypical. Here we present a case of atypical EBV-HLH simulating lymphadenitis on fluorrine-18-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT), with a view to consider this kind of EBV-HLH as a possible differential diagnosis in lymphadenitis. A 68 years old male who had episodic fever accompanied by weight loss and weakness for two weeks was studied. Finally, biopsies in bone marrow and spleen revealed hemophagocytic cells. He was diagnosed with EBV-HLH and treated with etoposide and prednisone. His condition started improving soon, and his abnormal laboratory findings were normalized at day 15. He remained in good clinical condition at 3 months follow-up after hospital discharge.

First case of Mycobacterium marseillense lymphadenitis in a child.

BACKGROUND: Nontuberculous mycobacteria (NTM) are pathogens that commonly affect the paediatric population and its most frequent manifestation is a cervicofacial lymphadenopathy. With the improvement of technologies, new species have been recently identified. CASE PRESENTATION: We report the first case of NMT lymphadenitis in a child caused by Mycobacterium marseillense, a newly described species belonging to Mycobacterium avium complex. CONCLUSIONS: Improving the identification of these newly discovered mycobacteria, further information will be available about their clinical involvement and their best treatment.

Use of Lymph Node Ultrasound Prior to Sentinel Lymph Node Biopsy in 384 Patients with Melanoma: A Cost-Effectiveness Analysis. / Valor de la ecografía ganglionar previa a la biopsia del ganglio centinela en 384 pacientes con melanoma: análisis de coste-efectividad.

BACKGROUND AND OBJECTIVES: Locoregional lymph node ultrasound is not typically included in guidelines as part of the staging process prior to sentinel lymph node biopsy (SLNB). The objective of the present study was to make a clinical and economic analysis of lymph node ultrasound prior to SLNB. MATERIALS AND METHODS: We performed a retrospective study of 384 patients with clinical stage I-II primary melanoma who underwent locorregional lymph node ultrasound (with or without ultrasound-guided biopsy) prior to SLNB between 2004 and 2015. We evaluated the reliability and cost-effectiveness of the strategy. RESULTS: Use of locorregional lymph node ultrasound avoided SLNB in 23 patients (6%). Ultrasound had a sensitivity of 46% and specificity of 76% for the detection of metastatic lymph nodes that were not clinically palpable. False negatives were significantly more common in patients aged over 60 years and in tumors with a thickness of less than 2mm. The staging process using SLNB and ultrasound with ultrasound-guided biopsy produced an increase of €16.30 in the unit price. Our cost-effectiveness analysis identified the staging protocol with ultrasound and SLNB as the dominant strategy, with a lower cost-effectiveness ratio than the alternative, consisting of SLNB alone (8,095.24 vs. €28,605.00). CONCLUSIONS: Ultrasound with ultrasound-guided biopsy for the diagnostic staging of melanoma prior to SLNB is a useful and cost-effective tool. This procedure does not substitute SLNB, though it does allow to avoid SLNB in a not insignificant proportion of patients.