[The Mexican Board of Pathology: microscopy examination before and after digital microscopy]. / Consejo Mexicano de Médicos Anatomopatólogos: su examen de microscopia, antes y después de su digitalización.

INTRODUCTION: The examination carried out by the COMMAP for the certification process assessed pathologist formed in dissimilar institutions. In 2007 COMMAP's governing body in turn, decided to digitize it. The purpose of this study is to investigate whether the conversion to virtual slides in the microscopy section, compared with the traditional have had an impact on the scores of the candidates. METHOD: The slides were scanned with high resolution. The virtual microscope is a standard computer screen where there is a program (Aperio Scope Image Viewer) that can display the scanned slides. The results of the microscopy section of the past nine years were compared; two groups were formed: 1) those without digitized examination, and 2) with it. The results were compared by Student t-test and Mann-Whitney. RESULTS: Of a 461 results 240 belonged to the first group and 221 to the second one. On a scale of 1-10, the average scores were 6.6 and 6.8, respectively (p > 0.6 and > 0.5).The minimum and maximum scores were also similar in each group. CONCLUSIONS: According to the results, the digitized exam in the COMMAP's certification process shows no difference between the digitized and the conventional versions.

Clinicopathologic characteristics of severe COVID-19 patients in Mexico City: A post-mortem analysis using a minimally invasive autopsy approach.

OBJECTIVE: Describe the histological findings of minimally ultrasound-guided invasive autopsies in deceased patients with severe SARS-CoV-2 and compare the diagnostic yield with open autopsies. DESIGN: Observational post-mortem cohort study. Minimally invasive ultrasound-guided autopsies were performed in fourteen deceased patients with a confirmed diagnosis of SARS-CoV-2 pneumonia. Histological and clinical findings of lung, kidney, and liver tissue are described and contrasted with those previously reported in the literature. SETTING: Single-center COVID-19 reference center in Mexico City. RESULTS: Fourteen minimally invasive autopsies revealed a gross correlation with open autopsies reports: 1) Lung histology was characterized mainly by early diffuse alveolar damage (12/13). Despite low lung compliances and prolonged mechanical ventilation, the fibrotic phase was rarely observed (2/13). 2) Kidney histopathology demonstrated acute tubular injury (12/13), interstitial nephritis (11/13), and glomerulitis (11/13) as the predominant features 3) Liver histology was characterized by neutrophilic inflammation in all of the cases, as well as hepatic necrosis (8/14) despite minimal alterations in liver function testing. Hepatic steatosis was observed in most cases (12/14). SARS-CoV-2 positivity was widely observed throughout the immunohistochemical analysis. However, endothelitis and micro thrombosis, two of the hallmark features of the disease, were not observed. CONCLUSION: Our data represents the largest minimally invasive, ultrasound-guided autopsy report. We demonstrate a gross histological correlation with large open autopsy cohorts. However, this approach might overlook major histologic features of the disease, such as endothelitis and micro-thrombosis. Whether this represents sampling bias is unclear.

IgG4-related kidney disease: experience from a Mexican cohort.

To evaluate the clinical/serological phenotype and outcomes of IgG4-related kidney disease. Case series of IgG4-related kidney disease from a cohort of 69 patients with IgG4-related disease. We defined kidney involvement as the presence of at least one of the following conditions: (A) laboratory parameters of kidney injury (proteinuria and/or elevated creatinine levels and/or hematuria); and/or (B) contrast-enhanced computed tomography features (multiple low-density lesions and/or nephromegaly and/or hypovascular solitary mass and/or renal pelvic lesion and/or perinephric lesions). We identified 17 patients with kidney involvement (24.6%), with a mean age of 53.6 ± 11.3 years; thirteen (76.5%) were male. Six patients fulfilled the laboratory criteria, six the imaging criteria, and five both. Five patients had a renal biopsy, the main histopathological diagnosis being IgG4 tubulointerstitial nephritis. Sixteen patients received glucocorticoids and 12 also immunosuppressors and/or biologics. Sixteen patients presented either total or partial renal remission at a median follow-up of 26 months, while one patient developed end-stage renal disease. Patients with kidney disease, as opposed to patients without kidney involvement, had a higher number of involved organs, higher IgG4-related disease responder index and IgG4 and IgG1 serum levels, higher prevalence of rheumatoid factor, and lower C3 and C4 levels. Our study emphasizes the systemic nature of IgG4-related disease, highlighting that renal involvement is usually present in a subset of patients with multisystemic disease, high IgG1 and IgG4 levels, and hypocomplementemia. Key Points • IgG4-RKD presents at a younger age in Mexican mestizo patients. • IgG4-RKD presents with proteinuria and kidney injury or as an asymptomatic imaging finding. • IgG4-RKD presents in the context of multisystemic disease, hypocomplementemia, and high IgG1 and IgG4 levels.

Calcineurin Inhibitors With Reduced-Dose Steroids as First-Line Therapy for Focal Segmental Glomerulosclerosis.

INTRODUCTION: High-dose corticosteroids remain the first-line therapy for focal and segmental glomerulosclerosis (FSGS), whereas calcineurin inhibitors (CNIs) are reserved for those patients resistant to corticosteroid therapy. METHODS: This is a retrospective cohort analysis in patients with primary FSGS diagnosed between 2007 and 2014. According to the administered treatment, patients were segregated into 3 groups: high-dose prednisone, first-line CNIs plus low-dose prednisone, and rescue CNIs. Cumulative corticosteroid doses were compared as well as response to therapy and long-term renal survival by Cox regression analysis. RESULTS: A total of 66 patients were included (39 treated with high-dose prednisone, 11 treated with first-line CNI, 16 treated with high-dose prednisone followed by rescue CNI). Cumulative doses of prednisone in the high-dose group were 9.3 g (interquartile range [IQR] = 7.5-12.5 g), compared to 2.5 g (IQR = 1.82-3.12 g) in the first-line CNI plus low-dose corticosteroid group and 13.8 g (IQR = 9.2-15.8 g) rescue CNI groups, respectively (P < 0.001). Time under corticosteroid management was also higher in the high-dose prednisone group compared to the first-line CNI group. There was a response to treatment in 76.9%, 72.7%, and 87.5% of high-dose prednisone, first-line CNI and rescue CNI groups, with complete remission in 48.7%, 36.4%, and 31.3% respectively. There was no difference in relapse incidence after treatment (48.4%, 44.4%, and 46.7%) or in 5-year renal survival (87.2%, 81.8%, and 87.5%). Baseline proteinuria, biopsy chronicity score, and response to therapy were independent predictors of renal survival. CONCLUSION: An initial CNI plus low-dose corticosteroid approach in primary FSGS reduces corticosteroid exposure with a response-to-therapy rate similar to that of the currently recommended high-dose corticosteroid regimen. These findings justify a randomized trial to formally test this hypothesis.

A Unique Cellular and Molecular Microenvironment Is Present in Tertiary Lymphoid Organs of Patients with Spontaneous Prostate Cancer Regression.

OBJECTIVE: Multiple solid cancers contain tertiary lymphoid organs (TLO). However, it is unclear whether they promote tumor rejection, facilitate tumor evasion, or simply whether they are a byproduct of chronic inflammation. We hypothesize that although chronic inflammation induces TLO formation, the tumor milieu can modulate TLO organization and functions in prostate cancer. Therefore, our study seeks to elucidate the cellular and molecular signatures in unique prostatectomy specimens from evanescent carcinoma patients to identify markers of cancer regression, which could be harnessed to modulate local immunosuppression or potentially enhance TLO function. METHODS: We used multicolor immunofluorescence to stain prostate tissues, collected at different stages of cancer progression (prostatic intraepithelial neoplasia, intermediate and advanced cancer) or from patients with evanescent prostate carcinoma. Tissues were stained with antibodies specific for pro-inflammatory molecules (cyclooxygenase 2, CXCL10, IL17), tumor-infiltrating immune cells (mature DC-LAMP+ dendritic cells, CD3+ T cells, CD3+Foxp3+ regulatory T cells (Treg), T bet+ Th1 cells, granzyme B+ cytotoxic cells), and stromal cell populations (lymphatic vessels, tumor neovessels, high endothelial venules (HEV), stromal cells), which promote prostate tumor growth or are critical components of tumor-associated TLO. RESULTS: Generally, inflammatory cells are located at the margins of tumors. Unexpectedly, we found TLO within prostate tumors from patients at different stages of cancer and in unique samples from patients with spontaneous cancer remission. In evanescent prostate carcinomas, accumulation of Treg was compromised, while Tbet+ T cells and CD8 T cells were abundant in tumor-associated TLO. In addition, we found a global decrease in tumor neovascularization and the coverage by cells positive for cyclooxygenase 2 (COX2). Finally, consistent with tumor regression, prostate stem cell antigen was considerably reduced in TLO and tumor areas from evanescent carcinoma patients. CONCLUSION: Collectively, our results suggest that COX2 and Treg are attractive therapeutic targets that can be harnessed to enhance TLO-driven tumor immunity against prostate cancer. Specially, the presence of HEV and lymphatics indicate that TLO can be used as a platform for delivery of cell-based and/or COX2 blocking therapies to improve control of tumor growth in prostate cancer.

Ultrastructure of tubular casts.

Tubular casts are found in a variety of conditions. Ultrastructural evaluation of casts has not been critically and systematically performed to define its usefulness. A total of 157 renal biopsies routinely processed for light microscopy (LM), immunofluorescence (IF), and electron microscopy (EM) were subjected to blind ultrastructural evaluation. The majority of the casts were in the distal nephron, and most of them (41.4%) were hyaline (HC). One-third (35%) of the cases showed admixed HC and granular casts (GC), and 25 cases (16%) had exclusively GC. In 7% of the cases, the morphology of the casts was distinctive enough to indicate specific composition. Four cases with red blood cell casts (5.6%) were associated with necrotizing glomerulopathy and IgA nephropathy. Four cases of myoglobulin casts were identified. Two cases with crystalized light-chain casts (1.3%) were associated with an underlying plasma cell dyscrasia. One case of acute pyelonephritis demonstrated polymorphonuclear cells casts (0.64%). A case of aminoglycoside toxicity revealed casts with myeloid bodies. Ultrastructural evaluation of casts may provide useful information that may be critical to establish or suggest a specific diagnosis.

[Neuroendocrine differentiation and markers of cell proliferation in a group of patients with prostate adenocarcinoma and normal or high serum prostate-specific antigen levels]. / Diferenciación neuroendocrina y marcadores de proliferación celular en adenocarcinoma de próstata en un grupo de casos con antígeno prostático específico normal vs elevado.

OBJECTIVE: Study the morphologic characteristics of neuroendocrine cells in prostate cancer with normal versus elevated prostate specific antigen (PSA). MATERIALS AND METHODS: 372 cases of prostate cancer were identified during a 13 year period, of which 19 displayed normal PSA (group I). Sixteen controls with elevated PSA and similar histopathological characteristics (group II) were included. We studied the degree of tumor necrosis, vascular and perineural invasion. Synaptophysin (SP), neuron specific enolase (NSE), PSA, Ki-67 and p53 inmunoreactivity were also analyzed. RESULTS: Group I positive findings were 61% PSA, 28.6% SP. 7.1% NSE, 50%p53, and 78.6% Ki-67. Group II positive findings were 93% PSA, 13.3% SP, 26.6% NSE 46.6% p53, and 66.7% Ki-67. When we used a <80% cut off point for PSA immunoreactivity in tumor cells, 69.2% of group I and 21.4% of group II were found. CONCLUSIONS: The sole histopathological finding that showed statistical significance was the tissular expression of the specific prostatic antigen in 80% of neoplasic cells in group I. The increase of neuroendocrine cells was associated with a smaller number of tissular antigen producing cells, a finding that could be more apparent if we were to study a larger sample size.

[Relationship between morphological diagnosis of NASH (non-alcoholic steatohepatitis) and liver function tests in a group of patients with morbid obesity]. / Relación entre el diagnóstico morfológico de EHNA (esteatohepatitis no alcohólica) y pruebas de función hepática en un grupo de pacientes con obesidad extrema.

UNLABELLED: The non-alcoholic steato-hepatitis (NASH) is a common disorder in obese, type 2 diabetics, female and patients with dislipidaemia. Hepatic biochemical test are abnormal. Despite the lack of its own morphological characteristics, NASH can be differentiated from other pathologies, the gold standard for diagnosis is liver biopsy. MATERIAL AND METHODS: We designed a retrolective, comparative, observational and cross-sectional study. Thirty-five obese subjects (11 men and 24 women) who underwent to bariatric surgery and liuer biopsy were included. Data were taken from clinical files, such as anthropometric and biochemical test. Those who had clinical history of related alcohol ingestion or liver damage related to drugs were excluded. A experimented pathologist classified the biopsies according to Brunt classification. Liver slides were classified according to 1) presence of NASH; 2) Inflammation and 3) Fibrosis. Differences between groups were analysed by ANOVA and Spearman correlation. RESULTS: We found differences between women (w) and men (m) for height (m: 1.71 +/- 0.9 vs. w:1.60 +/- 0.09m); weight (m:172.5 +/- 39.1 vs. w:126.9 +/- 24.1kg) and BMI (m:58.2 +/- 9.8 vs. w:49.8 +/- 9) , but not for NASH frequency. Nevertheless subjects with NASH (n = 29, 82.8%o) were older than those without NASH (38.3 +/- 9.6 vs. 29.5 +/- 5.2) and had higher aminotrasferases serum levels (AST: 33.1 +/- 19.2 vs. 23.7 +/- 6.3 ULIL; ALT: 36.5 +/- 19.8 vs. 20.3 +/- 7.6ULIL). NASH pa- tients and those with higher grade of histological inflammation had increment of transaminases and albumin levels. Fibrosis showed correlation only with AST (p = 0.020) and ALT (p = 0.002). CONCLUSION: The NASH frequency in patients who underwent to bariatric surgery for weight reduction is very high (82.8%) and exists correlation among liver test and histological findings but not with clinical because the clinical diagnosis is complicated.

Lesión renal rápidamente progresiva como presentación de necrosis tubular aguda de origen incierto en un maratonista. Diagnóstico diferencial nо siempre sencillo / Rapidly progressive renal injury as a manifestation of acute tubular necrosis with an uncertain origin in a marathonist: A differential diagnosis is not always simple

Resumen El síndrome de deterioro rápidamente progresivo de la función renal, corresponde a una forma de lesión renal aguda que cursa con un decremento acelerado y progresivo de la tasa de filtrado glomerular en horas a días o semanas. Una vez descartadas las causas prerrenales, es necesario establecer el diagnóstico diferencial con causas glomerulares, vasculares renales (trombosis), obstructivas, nefritis intersticial y necrosis tubular aguda. Se presenta un caso de deterioro rápidamente progresivo de la función renal, que fue manejado con esteroide intravenoso y plasma fresco congelado, por la probabilidad diagnóstica de microangiopatía trombótica, nefritis intersticial y glomerulonefritis rápidamente progresiva (GNRP). Posteriormente, se confirmó el diagnóstico de necrosis tubularaguda mediante biopsia renal, sin habertenidoalgún antecedente evidente que sugiriera la presencia y etiología de dicha entidad.

Abstract The rapidly progressive renal failure syndrome corresponds to an acute kidney injury that causes an accelerated decrease of the glomerular filtration rate in hours to days or weeks. After pre-renal causes were dismissed, a differential diagnosis with glomerularcauses, vascularcauses (thrombosis), obstructive causes, interstitial nephritis and acute tubular necrosis must be established. We describe the case of a rapidly progressive decline of the renal function that was managed with intravenous steroids and freshly frozen plasma due to the diagnostic probability of thrombotic microangiopathy, interstitial nephritis and rapidly progressive glomerulonephritis. Subseguently, an acute tubular necrosis was confirmed by a renal biopsy without any previous clinical evidence suggesting a clear presence or etiology of this entity.

Relación entre el diagnóstico morfológico de EHNA (esteatohepatitis no alcohólica) y pruebas de función hepática en un grupo de pacientes con obesidad extrema / Relationship between morphological diagnosis of NASH (Non-Alcoholic SteatoHepatitis) and liver function test in a group of patients with morbid obesity. Cases study

The non-alcoholic steato-hepatitis (NASH) is a common disorder in obese, type 2 diabetics, female and patients with dislipidaemia. Hepatic biochemical test are abnormal. Despite the lack of its own morphological characteristics, NASH can be differentiated from other pathologies, the gold standard for diagnosis is liver biopsy. Material and methods: We designed a retrolective, comparative, observational and cross-sectional study. Thirty-five obese subjects (11 men and 24 women) who underwent to bariatric surgery and liver biopsy were included. Data were taken from clinical files, such as anthropometric and biochemical test. Those who had clinical history of related alcohol ingestión or liver damage related to drugs were excluded. A experimented pathologist classified the biopsies according to Brunt classification. Liver slides were classified according to 1) presence of NASH; 2) Inflammation and 3) Fibrosis. Differences between groups were analysed by ANOVA and Spearman correlation. Results: We found differences between women (w) and men (m) for height (m: 1.71 ± 0.9 vs. w:1.60 ± 0.09m); weight (m: 172.5 ± 39.1 vs. w: 126.9 ± 24.1kg) and BMI (m:58.2 ± 9.8 vs. w:49.8 ± 9) , but not for NASH frequency. Nevertheless subjects with NASH (n = 29, 82.8%) were older than those without NASH (38.3 ± 9.6 vs. 29.5 ± 5.2) and had higher aminotrasferases serum levels (AST: 33.1 ± 19.2 vs. 23.7 ± 6.3 UL/L; ALT: 36.5 ± 19.8 vs. 20.3 ± 7.6UL/L). NASH patíents and those with higher grade of histological inflammation had increment of transaminases and albumin levels. Fibrosis showed correlation only with AST (p = 0.020) and ALT (p = 0.002). Conclusion.The NASH frequency in patients who underwent to bariatric surgery for weight reduction is very high (82.8%) and exists correlation among liver test and histological findings but not with clinical because the clinical diagnosis is complicated.

La esteatohepatitis no alcohólica (EHNA) es una alteración hepática frecuente en obesos, diabéticos tipo 2, mujeres y personas con dislipidemia. Clínicamente se acompaña de alteraciones en las pruebas de función hepática (PFH), y aunque carece de características morfológicas distintivas, puede ser razonablemente diferenciada de otras entidades, el método diagnóstico por excelencia es la biopsia hepática. Material y métodos. Se diseñó un estudio retrolectivo, comparativo, observacional y transversal en el que se incluyeron 35 pacientes obesos (11 hombres y 24 mujeres) sometidos a tratamiento quirárgico para reducción de peso, con biopsia hepática en el periodo transoperatorio. Se obtuvieron, del expediente clínico, datos antropométricos y de laboratorio. Se excluyeron los pacientes con antecedentes de ingestión de alcohol y medicamentos asociados a la presencia de EHNA. Se recabaron muestras de las biopsias hepáticas que fueron analizadas por un patólogo experimentado, empleando la clasificación de Brunt para estratificación de EHNA. Los datos se clasificaron de acuerdo con: 1) Presencia de EHNA, 2) Grado de inflamación, 3) Presencia de fibrosis. Las diferencias entre los grupos fueron analizadas con Krusskal Wallis y correlación de Spearman. Resultados. Se encontró diferencias entre hombres (H) y mujeres (M) en estatura: (H:1.71 ± 0.9. vs. M:1.60 ±0.09 m); peso (H: 172.5 ± 39.1 vs. M:126.9 ± 24.1 kg) e índice de masa corporal (H:58.2 ± 9.8 vs. M: 49.8 ± 9); no hubo diferencias en la frecuencia de EHNA por género. Los sujetos con diagnóstico morfológico de EHNA (n = 29, 82.8%) mostraron una edad promedio mayor que el grupo sin EHNA (38.3 ± 9.6 vs. 29.5 ± 5.2, respectivamente) del mismo modo, la concentración de transaminasas fue mayor para el grupo con EHNA (AST: 33.1 ± 19.2 vs. 23.7 ± 6.3 UL/ L; ALT: 36.5 ± 19.8 vs. 20.3 ± 7.6 UL/L). Los pacientes con EHNA y con mayor grado de inflamación histológica mostraron mayor elevación de transaminasas y albámina. La presencia de fibrosis correlacionó con la elevación de aspartato aminotransferasa (AST p = 0.020) y alanino aminotransferasa (ALT p = 0.002). Conclusión. Este estudio demuestra que la frecuencia de EHNA en pacientes obesos sometidos a cirugía para reducción de peso en la clínica de obesidad del Instituto es alta (82.8%) y que existe una buena correlación entre las pruebas de función hepática y las alteraciones morfológicas; sin embargo, las anteriores no correlacionan con las manifestaciones clínicas por lo que el diagnóstico clínico temprano es difícil.

Leiomiosarcoma asociado con el virus de Epstein-Barr en un adulto con trasplante renal / Leiomyosarcoma associated with epstein-barr virus in an adult with renal transplant

Recientemente se informó la asociación del virus de Epstein-Barr (VEB) y los tumores de músculo liso, principalmente en niños inmunosuprimidos; pero el papel que juega en la patogenia de estos tumores, no se ha esclarecido. Informamos un caso en que establecimos la presencia de VEB y leiomiosarcoma en un hombre de 28 años con insuficiencia renal crónica terminal que en 1994, recibió un trasplante renal. En 1996 ingresó con lesiones nodulares en ambas bases pulmonares, hígado, bazo, car anterior del muslo izquierdo y ganglios retroperitoneales; un año después falleció. En las biopsias de muslo e hígado se observó leiomiosarcoma. Las reacciones de inmunoperoxidasa fueron positivas para vimentina y para actina de músculo liso. La hibridación in situ fue positiva para antígenos nucleares del VEB (EBNA-2) en células neoplásicas. Este caso corresponde al primer sarcoma observado en pacientes trasplantados en nuestra institución como un caso poco frecuente de leiomiosarcoma asociado a VEB en adulto

Ependimoma mixopapilar con erosión e invasión de la columna vertebral. Presentación de dos casos / Myxopapillary ependymoma with vertebral invansion and erosion. A report of two cases

El ependimoma es el tumor intramedular más frecuente de los segmentos torácico, lumbar y sacro. De las tres variedades descritas por Kernohan, la mixopapilar es la que afecta casi exclusívamente al cono medular y al filum terminale. Excepcionalmente erosiona e invade a la columna vertebral. En este informe se presentan dos casos en los que se demuestra erosión e invasión, en uno por medio de estudio post-mortem, y en otro por medio de estudios de imagen y biopsia

Comparación de la utilidad del estudio transoperatorio y la biopsia por aspiración con aguja delgada en lesiones de tiroides. Analisis de casos discordantes en biopsias por aspiración / Comparison of utility of intraoperative examination and fine needle aspiration biopsy in thyroid lesions. Analysis of discrepant cases in aspiration biopsies

Introducción. Actualmente, el procedimiento más útil para el diagnóstico de nódulos tiroideos y para la selección de pacientes que requieren tratamiento quirúrgico es la biopsia por aspiración con aguja delgada (BAAD). La certeza diagnóstica de la BAAD ha llevado a cuestionar la utilidad del estudio transoperatorio (TOP) para definir la conducta quirúrgica. Objetivo. Comparar la certeza diagnóstica de la BAAD con la del TOP en pacientes con nódulos tiroideos tratados quirúrgicamente en un centro de tercer nivel. Analizar los casos discordantes en BAAD y sus causas. Material y métodos. Se compararon los diagnósticos TOP efectuados durante dos años (1997-98) con los diagnósticos preoperatorios efectuados mediante BAAD de nódulos tiroideos. El estándar de oro fue el diagnóstico realizado en cortes de la pieza quirúrgica incluidos en parafina. Se revisaron los expedientes clínicos y las laminillas de las BAAD de casos discordantes. Resultados. De un total de 1014 estudios TOP, 136 (13.4 por ciento) fueron de tiroides; de éstos, la mitad correspondieron a neoplásias malignas y el resto correspondió a adenomas y lesiones no neoplásicas. En el análisis para la discriminación de lesiones neoplásicas malignas y benignas, los resultados para los estudios de TOP y BAAD fueron respectivamente: sensibilidad 89 por ciento (IC: 78.2-95.1) y 97.7 por ciento (IC: 86.8-99.9), especificidad 100 por ciento (IC: 93.1-100) y 90 por ciento (IC: 90.4-96.7), valor predictivo positivo: 100 por ciento y 91.6 por ciento, valor predictivo negativo 90.4 por ciento y 97.3 por ciento, y certeza diagnóstica igual (94.6 por ciento y 94.1 por ciento). Las causas de mala clasificación son iguales a las informadas en otros estudios, e incrementan en gran medida el porcentaje de falsos positivos y negativos.Conclusiones. La BAAD es un procedimiento útil para el diagnóstico de nódulos tiroideos y para la selección de pacientes que deben ser sometidos a tratamiento quirúrgico. El estudio TOP es indispensable en aquellos casos en que la BAAD no ha sido concluyente, y en las lesiones en las que el diagnóstico depende en gran parte del aspecto macroscópico de la pieza quirúrgica.