Anatomy, immunohistochemistry, and numerical distribution of human splenic microvessels.

The microvascular architecture of the spleen plays an important role in the immunological function of this organ. The different types of vessels are related to different reticular cells each with their own immunomodulatory functions. The present study describes an immunohistochemical and morphometric analysis of the various types of vessels in 21 human autopsy non-pathological splenic samples. On an area of 785,656.37 µm2 for each sample, we classified and quantified the type and number of vascular structures, each according to their morphology and immunohistochemical profile, and obtained the ratios between them. The distribution of trabecular vessels and the characteristics of the venules are reviewed. In our material the so-called "cavernous perimarginal sinus" (anatomical structure previously described by Schmidt et al., 1988) was observed and interpreted as a curvilinear venule shaped by the follicle in contact with the trabecular vein. Our material comprised 261 trabeculae (containing 269 arterial sections and 508 venous sections), 30,621 CD34+ capillaries, 7739 CD271+ sheathed capillaries, 2588 CD169+ sheathed capillaries, and 31,124 CD8+ sinusoids. The total area (TA) (14,765,714.88 µm2) occupied by the sinusoidal sections of the 21 cases was much higher than the TA of the capillary sections (1,700,269.83 µm2). Similarly, the TA (651,985 µm2) occupied by the sections of the trabecular veins was much higher than the TA of the trabecular arteries (88,594 µm2). The total number of CD34+ capillaries and of sinusoids CD8+ was similar for the sum of the 21 cases, nevertheless there were large differences in each case. Statistically the hypothesis that the number of capillaries and sinusoids are present with the same frequency is discarded. In view of the absence of a numerical correlation between capillaries and sinusoids, we postulate that very possibly the arterial and the venous vascular trees are two anatomically independent structures separated by the splenic cords. We believe that this is the first work where splenic microvascularization is simultaneously approached from a morphometric and immunohistochemical point of view.

Low levels of WWOX protein immunoexpression correlate with tumour grade and a less favourable outcome in patients with urinary bladder tumours.

AIMS: To correlate the immunohistochemical detection of WWOX with histological measures and disease progression within the whole spectrum of urothelial bladder neoplasms. METHODS AND RESULTS: One hundred and one patients with primary bladder tumours were retrospectively analysed. Immunohistochemically, a polyclonal antibody was utilized and the level of WWOX protein expression was analysed by using a combined score system based on intensity of the reaction and percentage of immunoreactive tumour cells. WWOX protein expression was consistently expressed in non-neoplastic urothelium, whereas a progressive loss of immunoreactivity was observed as tumour grade and stage increased (P < 0.05). Principal component analysis showed that reduced WWOX immunoexpression was significantly associated with high histological grades (P = 0.001), advanced stage (P = 0.002), tumour size (P = 0.04) and cancer progression (P = 0.028). Invasive urothelial carcinomas of the bladder with squamous metaplasia presented the lowest levels of WWOX protein. Kaplan-Meier analyses demonstrated a significant correlation between loss of WWOX expression and a shorter progression-free survival (P = 0.042), whereas the prediction of overall survival achieved borderline significance (P = 0.053). CONCLUSION: Loss of WWOX immunoexpression strongly correlates with classical clinicopathological factors and appears to be a potential predictive marker of progressive disease.

Benign, preinvasive and invasive ductal breast lesions. A comparative study with quantitative techniques: morphometry, image- and flow cytometry.

The histological distinction between ductal hyperplasia of the breast, atypical ductal hyperplasia and ductal carcinoma in situ is difficult and subjective. To gain a better understanding of these lesions, we performed a comparative study comprising 20 cases of ductal hyperplasia without atypia, 20 cases of ductal hyperplasia with atypia, and 30 cases of ductal carcinoma in situ (well-, moderately- and poorly-differentiated), using quantitative techniques: image cytometry analysis, morphometry and DNA analysis, and DNA flow cytometry. Our results confirm that the mean nuclear area and volume progressively decreased from ductal carcinoma in situ to ductal hyperplasia without atypia. The difference was significant (p < 0.05) when comparing hyperplasia without atypia with hyperplasia with atypia and hyperplasia with atypia with poorly differentiated ductal carcinoma in situ. Atypical ductal hyperplasia values were comparable to those of well-differentiated ductal carcinoma in situ. DNA image cytometry proved significant (p < 0.05) when comparing hyperplasia without atypia with hyperplasia with atypia and hyperplasia with atypia with moderately- and poorly-differentiated ductal carcinoma in situ. DNA flow cytometry revealed significant differences only in the distribution of the DNA ploidy patterns (p < 0.05) when comparing hyperplasia without atypia with moderately- and poorly-differentiated DCIS. A comparison of the results obtained by image and flow cytometry showed that in 90% of the cases the IC and FC values were coincident, whereas in the remaining cases the DNA index was aneuploid by IC and diploid by FC.

[Problems in defining melanoma regression and prognostic implication]. / Regresión en el melanoma: problemas en su definición e implicación pronóstica.

Between 10 % and 35 % of all melanomas show histological regression. That is, there is an area within the melanoma where the tumor retreats or disappears to be progressively replaced by fibrosis with presence of melanophages and variable degrees of inflammation, and neovascularization. Such regression is generally considered an indicator of poor prognosis in melanoma, although a number of studies contradict this affirmation. In this review, we summarize the leading articles about the influence of regression on melanoma prognosis. The results of these studies are very inconsistent, and so the prognostic significance of regression is somewhat controversial. We believe that some of these differences can be explained by differing criteria for regression and so we propose clear histological criteria to define early and sustained regression.

Radiation-Induced Leiomyosarcoma after Breast Cancer Treatment and TRAM Flap Reconstruction.

The development of a radiation-induced sarcoma (RIS) in the post mastectomy thoracic treatment volume is an infrequent, but recognized, event. Its frequency is rising in relation with increasing survival of breast cancer patients treated with adjuvant radiation therapy, and is associated with poor prognosis despite treatment. We present a case of leiomyosarcoma in a patient who underwent mastectomy followed by radiotherapy for invasive ductal carcinoma. A delayed TRAM flap reconstruction was performed 10 years after and a rapid growing mass under the reconstructed flap appeared, on routine follow-up, twenty years later. This report analyzes the diagnostic and therapeutic approach of patients with RIS.

Risk groups in patients with bladder cancer treated with radical cystectomy: statistical and clinical model improving homogeneity.

PURPOSE: In this study we identified homogeneous risk groups, with no survival overlap among the subgroups that make up each risk group, in patients with transitional cell carcinoma of the bladder treated with radical cystectomy alone. MATERIALS AND METHODS: Predictive factors for tumor death were analyzed with univariate and multivariate analysis among a group of 298 patients with transitional cell carcinoma of the bladder treated with radical cystectomy alone. Independent variables were progressively incorporated according to their statistical power in a stepwise process identifying a model with independent subgroups. The risk groups were identified according to different survival cutoff points including subgroups with similar survival. To search a clinical application and to check the strength of this model a new model was also set up using the weight score based on the size of hazard ratio from multivariate analysis. RESULTS: Univariate analysis demonstrated that lymphatic invasion status, pathological stage (P), lymph node status (N) and prostatic stroma status (St) were predictive variables for tumor death, and the latter 3 were independent variables in the multivariate analysis. By taking the most powerful, N, as the reference variable, and progressively incorporating additional variables, a model was found including 7 independent subgroups. In this model only 2 subgroups, N1 and N2-3, included more than 1 category and their survival was also calculated. Three risk groups were identified establishing different survival cutoffs. The 5-year cancer specific survival rate was 86.4% for low risk (P1-2N0St-), 64.4% (range 60.9% to 65.3%) for intermediate risk (P1-2N1St-, P3N0St-, HR = 2.7) and 28.1% (range 0% to 47.7%) for high risk (N2-3, P4, St+, N1P3, HR = 8.7). This model was also reproduced using the weight score based on the size of the hazard ratio from the multivariate analysis CONCLUSIONS: Three homogeneous risk groups were identified with high statistically significant survival differences among them and no survival overlap among subgroups that make up the risk groups.

Immunohistochemical expression of Ki-67 antigen, cox-2 and Bax/Bcl-2 in prostate cancer; prognostic value in biopsies and radical prostatectomy specimens.

PURPOSES: To elucidate the prognostic value of the immunohistochemical (IHC) expression of Bcl-2, Bax, Cox-2 and Ki-67 antigen in biopsy cores (C) and surgical specimens (SP) of prostate cancer (PC) and to determine the C to SP reproducibility. MATERIAL AND METHODS: The IHC study was carried out in 91 patients operated by means of radical prostatectomy (RP) with available formalin-fixed paraffin-embedded material from both C and SP. RESULTS: The IHC expression of Bcl-2 in C and SP was very low (5%). Bax was expressed in almost all the patients and did not show any prognostic value. We observed a good reproducibility between C and SP for all molecules except with Bax. In prostate C, Ki-67 and Cox-2 were considered positive in 42.9% and 67% of the patients respectively, and were related to disease-free survival in the univariate analysis. The expression of these two markers in SP was observed in 51.6% and 79.1% of the patients and the expression of Ki-67 in SP maintained its independence as prognostic factor in the multivariate analysis related to disease-free survival. CONCLUSIONS: The IHC expression of Ki-67 and Cox-2 proteins in our study do offer valuable prognostic information, mostly the first one. Thus, we think these markers might be studied in larger series of patients for its further validation as prognostic factors in prostate biopsies.

Clinicopathological and immunohistochemical analysis of 20 cases of Merkel cell carcinoma in search of prognostic markers.

AIMS: To evaluate the clinicopathological and immunohistochemical characteristics of Merkel cell carcinoma (MCC) in an attempt to find new, potentially significant, prognostic markers. METHODS AND RESULTS: Clinical data and follow-up, histopathological features (pattern, cell size, thickness, mitoses, vascular invasion, lymphocytic infiltration) and immunohistochemical detection [CK20, thyroid transcription factor (TTF-1), chromogranin A, synaptophysin, p53, Ki67, Fli-1, CD99, c-Kit] were evaluated in 20 cases of MCC. Fli-1 and CD99 were detected in 90% and 55% of cases, respectively. Tumour size>30 mm, stage II, 'absent' lymphocytic infiltration, and the presence of>50% of Ki67+ tumour cells, were found to be prognostic indicators of disease-free interval (DFI), but only 'absent' lymphocytic infiltration constituted an independent prognostic factor of DFI after multivariate analysis. For overall survival, the same variables, together with local recurrence and lymph node involvement, had prognostic significance, with only local recurrence as an independent prognostic factor after multivariate analysis. CONCLUSIONS: Absence of lymphocytic infiltration and Ki67 immunoreactivity in more than 50% of tumour cells should be evaluated in conjunction with other well-known prognostic markers in MCC. Furthermore, recognizing that Fli-1 and CD99 expression is commonly found in MCC by immunohistochemistry may avoid misinterpretation in the differential diagnosis of MCC with other small round cell tumours.

The 3-month clinical response to intravesical therapy as a predictive factor for progression in patients with high risk superficial bladder cancer.

PURPOSE: We analyzed the 3-month clinical response to intravesical therapy as a factor predictive of progression in patients with high risk superficial bladder cancer. MATERIAL AND METHODS: We evaluated 191 patients with high risk superficial bladder cancer, 111 with secondary or associated bladder carcinoma in situ and 80 with stage T1 grade 3 disease who were treated with intravesical therapy. We considered only clinically complete and no responses at the 3-month endoscopic study. To determine the predictive value of the 3-month clinical response we differentiated progression into superficial and invasive types. RESULTS: At a median followup of 73 months 91 patients (47.6%) had progression, which was superficial in 48 (25. 1%) and invasive in 43 (22.5%). Invasive progression was associated with significantly higher cause specific mortality than superficial progression (p = 0). In the latter cases cause specific mortality was higher than in those without progression (p = 0.001). Although cystectomy significantly decreased the cause specific mortality rate in patients with invasive progression (p = 0.0001), this rate was high at 46.3%. Univariate and multivariate analyses revealed that the 3-month clinical response was a significant predictive factor for progression. Moreover, stratifying this variable showed that this response was the only independent factor predictive of invasive progression in cases of no response with stage T1 grade 3 tumor, bladder carcinoma in situ, or prostate mucosa or duct involvement (p = 0). In our series 41 patients (21.5%) did not respond after intravesical therapy at the 3-month evaluation, including 29 with stage T1 grade 3 disease, bladder carcinoma in situ, or prostate mucosa or duct involvement. Progression in 24 of these 29 patients (82.3%) was classified as invasive in 21 (73.6%). CONCLUSIONS: Invasive progression threatens the cause specific survival of patients with high risk superficial bladder cancer even when cystectomy is performed. The 3-month clinical response was an excellent predictive factor for invasive progression. Early cystectomy should be considered when stage T1 grade 3 tumor, bladder carcinoma in situ, or prostate mucosa or duct involvement is present at the 3-month clinical evaluation.

Extravesical involvement in patients with bladder carcinoma in situ: biological and therapy implications.

PURPOSE: The biological and therapeutic implications of extravesical involvement in patients with bladder carcinoma in situ were analyzed. MATERIALS AND METHODS: Of 138 patients with bladder carcinoma in situ 87 (63%) had extravesical involvement, including the prostate in 53, the upper urinary tract in 11 and both structures in 23 (pan-urothelial involvement). With survival free of disease as an end point, univariate and multivariate analyses were done. RESULTS: Patients with extravesical involvement had worse survival than those with bladder carcinoma in situ alone (p < 0.001). In multivariate analysis prostate involvement (p = 0.0007) and pan-urothelial involvement (p = 0.0001) were selected as significant variables. When pathological patterns were considered prostatic stromal invasion (p = 0.0002) was the only variable selected. With these data 3 patient groups with disease mortality risk were defined. CONCLUSIONS: Prostate involvement and pan-urothelial involvement behave as independent prognostic factors, with the latter probably reflecting an extremetly diffuse character of carcinoma in situ. However, the upper urinary tract had no influence on survival. In patients with upper urinary tract and/or prostatic involvement limited to the mucosa treatment can be conservative. Patients with ductal or stromal involvement should undergo radical treatment. For upper tract involvement conservative approaches may be considered if there are no radiological signs of invasion or low grade tumor.

Clinical panurothelial disease in patients with superficial bladder tumors: therapeutic implications.

PURPOSE: We established the prognostic and therapeutic implications of panurothelial involvement in patients with superficial bladder tumors for optimizing therapeutic approaches in those at risk for panurothelial involvement. MATERIALS AND METHODS: We studied the records of 35 patients with clinical panurothelial disease. Since all of these patients presented with high risk superficial bladder cancer during followup, they were included in specific therapeutic and followup regimens. Radical procedures or conservative therapies were indicated mainly according to pathological examination and the recurrence pattern. RESULTS: Panurothelial involvement was a late stage of a recurrent and diffuse process that essentially developed in sequences, in which all patients presented with high risk superficial bladder tumors. This process involved continued relapse after panurothelial involvement developed. Notably 19 patients (79.1%) at risk for recurrence had repeat relapse in the urothelium. In the upper urinary tract 12 patients (34.3%) had bilateral involvement, including 7 (41.2%) of 17 patients after cystectomy. We identified 2 subgroups of patients. The subgroup with a better prognosis included 27 patients in whom late panurothelial disease developed step by step after a complete response to intravesical therapy, including 14 (51.8%) who were free of disease. The other subgroup with a poor prognosis included 8 patients with concurrent bladder carcinoma in situ and prostate involvement as well as early panurothelial disease, of whom only 2 (25%) were disease-free. All patients underwent many therapeutic approaches. A mean of 7.5 surgical procedures per patient were done, including a mean of 5.5 transurethral resections, a mean of 1 conservative approach to the upper urinary tract and a mean of 1.1 radical procedures. At a median followup of 111 months 10 patients (28.5%) were disease-free but only 7 (20%) retained the bladder, while 19 (54.3%) died of tumor. CONCLUSIONS: Patients with high risk superficial bladder multifocal tumors and associated bladder carcinoma in situ are at high risk for panurothelial involvement. Radical cystectomy may be recommended in these patients when initially or during followup, concurrent high risk superficial bladder tumors and prostate involvement develop or prostate involvement recurs. For the upper urinary tract conservative therapies may be advisable when noninfiltrating tumors are diagnosed even after cystectomy due to the high rate of bilateral new onset disease. When cystectomy is performed, extended excision of the upper urinary tract and pyelo-intestinal anastomosis may be considered.

The prostate involvement as prognostic factor in patients with superficial bladder tumors.

PURPOSE: The prognostic value of prostate involvement in patients with superficial bladder cancer was analyzed. MATERIALS AND METHODS: We studied 96 patients with prostate involvement. Taking progression-free survival rate as an end point, univariate and multivariate analyses were done. RESULTS: The presence or absence of bladder carcinoma in situ is related to poor and good prognoses, respectively (p < 0.001). Stromal invasion (p < 0.001) and pan-urothelial involvement (p = 0.03) were also identified as independent factors of poor prognosis. CONCLUSIONS: Patients with tumor limited to the mucosa can be treated conservatively. Cystoprostatectomy can be performed in patients with ductal involvement. The prognosis of patients with stromal invasion is poor despite radical treatment.

Cytogenetic study of angiosarcoma of the breast.

Angiosarcoma of the breast is quite rare, and the development of cutaneous angiosarcoma after segmental mastectomy and radiation therapy is even less common. A cytogenetic analysis of a mammary angiosarcoma arising in a breast after previous irradiation and segmental mastectomy for infiltrating ductal carcinoma revealed multiple clonal rearrangements involving chromosomes X, 1, 2, 3, 4, 5, 6, 7, 8, 9, 15, 17, 20, and 22. No cytogenetically analyzed angiosarcomas of the breast have been reported before.

Regresión en el melanoma: problemas en su definición e implicación pronóstica / Problems in Defining Melanoma Regression and Prognostic Implication

Entre un 10 y un 35% de todos los melanomas presentan regresión histológica, es decir, un área en el seno del melanoma en el que el tumor disminuye o desaparece y es sustituido progresivamente por fibrosis, con cantidades variables de melanófagos, inflamación y neovascularización. Aunque mayoritariamente se considera la presencia de regresión como un factor de mal pronóstico en el melanoma, existen varios trabajos que contradicen esta idea. En esta revisión resumimos los principales artículos publicados sobre la influencia de la regresión en el pronóstico del melanoma y encontramos resultados muy dispares, de modo que el significado pronóstico de la regresión en el melanoma es, a la vista de los trabajos publicados, cuando menos controvertido. Pensamos que parte de las diferencias encontradas se pueden deber a la disparidad en cuanto a los criterios utilizados para definir la regresión, y por ello proponemos unos criterios histológicos que aclaren los conceptos de regresión temprana y establecida (AU)

Between 10% and 35% of all melanomas show histological regression. That is, there is an area within the melanoma where the tumor retreats or disappears to be progressively replaced by fibrosis with presence of melanophages and variable degrees of inflammation, and neovascularization. Such regression is generally considered an indicator of poor prognosis in melanoma, although a number of studies contradict this affirmation. In this review, we summarize the leading articles about the influence of regression on melanoma prognosis. The results of these studies are very inconsistent, and so the prognostic significance of regression is somewhat controversial. We believe that some of these differences can be explained by differing criteria for regression and so we propose clear histological criteria to define early and sustained regression (AU)

Linfangiosarcoma en paciente mastectomizada (síndrome de Stewart-Treves) / No disponible

El linfangiosarcoma postmastectomía (LPM) es un tumorvascular muy infrecuente y agresivo, que asienta habitualmenteen brazos portadores de un linfedema de larga evolución,tras una mastectomía radical por cáncer. Su incidencia es del0,45% en pacientes que sobreviven 5 años tras la mastectomíaradical. La etiología de estos tumores es aún completamentedesconocida. En la actualidad no existe un tratamientoestandarizado. Las opciones terapéuticas incluyen la exéresisquirúrgica, amputación de la extremidad afectada, desarticulación,radioterapia y quimioterapia. El pronóstico es malo. Lasupervivencia tras el diagnóstico oscila entre 8 y 15 meses.Presentamos el caso de una paciente con linfangiosarcomapostmastectomía radical y radioterapía(AU)

Lymphangiosarcoma postmastectomy is an uncommonvascular tumor, arising in the area of chronically lymphoedematousextremity, after radical mastectomy and radiotherapyin patients with breast cancer. It shows an incidence of 0,45%among patients that survive more than five years after radicalmastectomy. The etiology of this enigmatic tumor is not yetcompletely understood. There is no standard treatment. Thetreatment options include radical ablative surgery, amputation,radiation therapy and chemotherapy. The prognosis is poor.Survival after diagnosis ranged from 8 to 15 months. We reportthe case of patients with LPM and RT(AU)

¿Es la adenomastectomía una alternativa a la mastectomía total en el carcinoma ductal in situ no tributario de tratamiento conservador? / No disponible

Se estudia la adenomastectomía (ADM) como alternativaterapéutica a la mastectomía simple en carcinoma ductal insitu (CDIS).Ochenta y dos pacientes diagnosticadas de CDIS con indicaciónde mastectomía, han sido tratadas con ADM y reconstruccióninmediata. Con una mediana de seguimiento de86,33 meses, se han diagnosticado 8 recidivas.La ADM puede ser una opción menos agresiva y estéticamentemejor aceptada en los casos de CDIS, con una tasa derecaídas locales intermedia entre la de la mastectomía simple yel tratamiento conservador(AU)

Subcutaneous mastectomy has been studied as an alternativesurgical treatment to conventional total mastectomy in thosepatients, diagnosed of ductal carcinoma in situ (DCIS). Subcutaneousmastectomy has been performed in 82 women withimmediate reconstruction. With a median follow-up of 86,3months, 8 recurrences have been diagnosed.Subcutaneous mastectomy may be a good and acceptedtreatment option in cases were radical surgery is needed withan intermediate local failure rate(AU)

Determinación del estatus del oncogén Sc-erbB-2/HER2 en el cáncer de mama invasivo: análisis comparativo entre los procedimientos de inmunohistoquímica (clon CB11y HercepTest), FISH y PCR diferencial / Determination of the status of the c-erbB-2/HER2 oncogene in invasive breast cancer: comparison of immunohistochemical (CB11 clone and Hercept Test), FISH and differential PCR procedures

La demanda clínica del estatus del oncogén HER-2/c-erbB-2 (HER2) en las muestras de cáncer de mama se ha incrementado considerablemente debido a que este marcador proporciona una valiosa información pronóstica, predictiva y terapéutica. En este sentido, se dispone de una amplia variedad de métodos para la detección del estatus de HER2, aunque hasta la fecha no existe un test lo suficientemente reproducible y sensible. Con el objeto de elegir el procedimiento más adecuado para la determinación del estatus del oncogén HER2, hemos analizado un total de 102 cánceres de mama invasivo para el estudio de la hiperexpresión proteica mediante inmunohistoquímica (IHQ), con el anticuerpo monoclonal CB11 y el kit HercepTest, y para la determinación de la amplificación génica mediante hibridación fluorescente in situ (FISH) y PCR diferencial (dPCR). La hiperexpresiónde HER2, determinada con el clon CB11 (grupo C) y el kit HercepTest (score 2+ y 3+), se observó en 19 muestras (18,6 por ciento) mientras que la amplificación génica se detectó en 31 (30,4 por ciento) y 14 (13,7 por ciento) de los casos mediante FISH y dPCR respectivamente, correspondiendo la mayoría de los casos con hiperexpresión/amplificación de HER2 a tumores de alto grado. Hemos encontrado concordanciasdel 78-80 por ciento y 93-95 por ciento entre la IHQ vs FISH e IHQ vs dPCR respectivamente. Considerando la técnica delFISH como el estándar de referencia, encontramos una sensibilidad y especificidad del 48,4 por ciento y 94,3 por ciento para el anticuerpo CB11, del 45,2 por ciento y 92,9 por ciento para el HercepTest, y del 45,2 por ciento y 100 por ciento para la dPCR. Por tanto, y de acuerdo a la sensibilidad, especificidad y el alto grado de concordancia entre la IHQ y la dPCR, sugerimos el uso de la IHQ, especialmente con el kit HercepTest, para la determinación del estatus del oncogén HER2. Sin embargo, y debido a que la sensibilidad de la IHQ es inferior a la delFISH, sugerimos llevar a cabo este último procedimiento en aquellos casos en los que los resultados de la IHQ no son definitivos para su evaluación clínica (AU)

Linfadenectomía selectiva (ganglio centinela) en el melanoma. Experiencia con 55 casos / Selective lymphadenectomy (sentinel node) in melanoma. A study of 55 cases

Introducción. El ganglio centinela (NC) es la primera estación de drenaje linfático de una lesión primitiva y, por tanto, con la máxima probabilidad de albergar una metástasis. El objetivo de este trabajo es ahorrar la morbilidad y coste de linfadenectomías innecesarias en pacientes con melanoma clínicamente no diseminado (75-89 por ciento) y mejorar la estadificación por localización del NC fuera del área de drenaje habitual. Pacientes y métodos. Se han estudiado 55 pacientes con diagnóstico de melanoma de riesgo intermedio (Breslow 0,75-4 mm).Para localizar las áreas de drenaje linfático, a todos los pacientes se les realizó una linfogammagrafía mediante la inyección intradérmica subcicatrizal de sulfuro coloidal-99mTc antes de la intervención. Veinte minutos antes de ésta se inyectó igualmente 1 cm3 de azul de isosulfán (Lymphazurin®).La búsqueda intraoperatoria del NC se realizó en 9 pacientes con el colorante exclusivamente y en 46 con la técnica combinada del colorante y una sonda detectora de rayos gamma (Navigator®).Resultados. El NC se localizó en 53 pacientes (96 por ciento), estaba infiltrado en siete de ellos (13 por ciento) y era el único ganglio afectado en cinco (71,5 por ciento). Conclusiones. La linfadenectomía selectiva en el melanoma es una técnica de escasa morbilidad, que puede evitar linfadenectomías completas innecesarias en pacientes con melanoma de riesgo intermedio (AU)