Blanca Paño

Pathways of Lymphatic Spread in Male Urogenital Pelvic Malignancies

Regional lymph node involvement in urogenital malignancies (category N in the TNM classification system) is a significant radiologic finding, with important implications for treatment and prognosis. Male urogenital pelvic cancers commonly spread to iliopelvic or retroperitoneal lymph nodes by following pathways of normal lymphatic drainage from the pelvic organs. The most likely pathway of nodal spread (superficial inguinal, pelvic, or paraaortic) depends on the tumor location in the prostate, penis, testis, or bladder and whether surgery or other therapy has disrupted normal lymphatic drainage from the tumor site; knowledge of both factors is needed for accurate disease staging. At present, lymph node status is most often assessed with standard anatomic imaging techniques such as multidetector computed tomography or magnetic resonance (MR) imaging. However, the detection of nodal disease with these techniques is reliant on lymph node size and morphologic characteristics, criteria that provide limited diagnostic specificity. Functional imaging techniques, such as diffusion-weighted MR imaging performed with or without a lymphotropic contrast agent and positron emission tomography, may allow a more accurate nodal assessment based on molecular or physiologic activity.

Usefulness of MDCT to Differentiate Between Renal Cell Carcinoma and Oncocytoma: Development of a Predictive Model

OBJECTIVE The objective of our study was to identify the most useful parameters to differentiate between renal cell carcinoma (RCC) and oncocytoma using four-phase CT. MATERIALS AND METHODS Ninety-seven patients with solid renal lesions who underwent surgery with four-phase preoperative CT evaluation and with pathologic diagnosis of RCC or oncocytoma were included in the study. Features of tumors and the enhancement pattern in the four CT phases were evaluated and analyzed. Logistic regression models were used to assess independent predictors for malignancy. RESULTS Histopathologically, 13 tumors were oncocytomas and 84 were RCCs. RCCs were larger (6.20 cm vs 3.21 cm, p = 0.0004) and more often enhanced heterogeneously (66 vs 6, p = 0.02). Lesions that were larger than 4 cm showed a significantly higher risk of malignancy (p = 0.0046). Significant differences were found in intensity of nodule enhancement between the nephrographic and the excretory phases with respect to the unenhanced phase (p = 0.003 and p = 0.0026). At multivariate analysis, parameters that were independent predictors of malignancy were enhancement pattern, with RCCs more often having heterogeneous enhancement than oncocytomas (odds ratio [OR], 0.18; 95% CI, 0.04-0.90), and nodule enhancement in the excretory phase in relation to the unenhanced phase, with RCCs showing lower enhancement (OR, 0.93; 95% CI, 0.88-0.97), and a size larger than 4 cm (OR, 4.01; 95% CI, 0.70-23.14). CONCLUSION The combination of different CT parameters including lesion size larger than 4 cm, lesion enhancement in the excretory phase in relation to the unenhanced phase, and heterogeneous enhancement pattern helps distinguish RCC from oncocytoma.

Pathways of Lymphatic Spread in Gynecologic Malignancies

Precise radiologic evaluation of regional adenopathic involvement in pelvic gynecologic tumors is fundamental to clinical practice because of its prognostic and therapeutic significance. Likewise, the identification of metastatic adenopathies at posttreatment imaging is essential for assessing response and detecting recurrence. Similar to urologic neoplasms, gynecologic neoplasms most often spread regionally to the pelvic and retroperitoneal lymph nodes, following the normal drainage pathways of the pelvic organs. Familiarity with routes of dissemination, treatment options, and means of analyzing lymph node characteristics is crucial to determine the extent of disease. Two staging systems can be used in characterizing gynecologic malignancies: the FIGO (International Federation of Gynecology and Obstetrics) system, which is the most commonly and universally used, and the TNM (tumor, node, metastasis) system, which is based on clinical and/or pathologic classification. Anatomic assessment with multidetector computed tomography (CT) and magnetic resonance (MR) imaging is still the most commonly used technique for the detection of lymph node spread, which is mainly based on morphologic criteria, the most important of which is nodal size. However, size has limited diagnostic specificity. Consequently, functional imaging techniques such as diffusion-weighted MR imaging, positron emission tomography combined with CT, lymphoscintigraphy, and sentinel lymph node mapping, which are based on molecular and physiologic activity and allow more precise evaluation, are often incorporated into diagnostic imaging protocols for staging of gynecologic malignancies.

Magnetic resonance imaging of adenoma malignum of the uterine cervix with pathologic correlation: a case report

Adenoma malignum (AM) is considered a rare subtype of cervical adenocarcinoma. Although previous reports have described magnetic resonance findings, none of these reports evaluated the utility of diffusion-weighted imaging in the differential diagnosis of AM and other multicystic cervical lesions. We present a case report of an AM that did not show restriction on the apparent diffusion coefficient map, which can be explained by the low cellularity of the tumor. This is consistent with the proper correlation between the diffusion imaging and histopathology of the tumor. In this way, AM can present with high apparent diffusion coefficient values, as in benign cervical lesions. Therefore, the combination of a solid multicystic lesion that invades the cervical stroma on T2-weighted magnetic resonance images and the absence of restriction on the apparent diffusion coefficient map are very suggestive of AM.

Utilidad de la tomografía computarizada de doble energía con un programa específico para la identificación de litiasis renales de ácido úrico

OBJECTIVE To prospectively evaluate the usefulness of dual-energy computed tomography (DECT) with and without dedicated software in identifying uric acid kidney stones in vivo. MATERIAL AND METHODS We studied 65 kidney stones in 63 patients. All stones were analyzed in vivo by DECT and ex vivo by spectrophotometry. We evaluated the diagnostic performance in identifying uric acid stones with DECT by analyzing the radiologic densities with dedicated software and without using it (through manual measurements) as well as by analyzing the attenuation ratios of the stones in both energies with and without the dedicated software. RESULTS The six uric acid stones included were correctly identified by evaluating the attenuation ratios with a cutoff of 1.21, both with the dedicated software and without it, yielding perfect diagnostic performance without false positives or false negatives. The study of the attenuations of the stones obtained the following values on the receiver operating characteristic curves in the classification of the uric acid stones: 0.92 for the measurements done with the software and 0.89 for the manual measurements; a cutoff of 538 HU yielded 84% (42/50) diagnostic accuracy for the software and 83.1% (54/65) for the manual measurements. CONCLUSIONS DECT enabled the uric acid stones to be identified correctly through the calculation of the ratio of the attenuations in the two energies. The results obtained with the dedicated software were similar to those obtained manually.

Accuracy of unenhanced magnetic resonance angiography for the assessment of renal artery stenosis

Purpose To evaluate the accuracy of unenhanced magnetic resonance angiography (U-MRA) using balanced steady-state free precession (SSFP) sequences with inversion recovery (IR) pulses for the evaluation of renal artery stenosis. Materials and methods U-MRA was performed in 24 patients with suspected main renal artery stenosis. Two radiologists evaluated the quality of the imaging studies and the ability of U-MRA to identify hemodynamically significant main renal artery stenosis (RAS) defined as a stenosis ≥50% when compared to gold standard tests: contrast-enhanced magnetic resonance angiography (CE-MRA) (18 patients) or digital subtraction arteriography (DSA) (6 patients). Results A total of 44 main renal arteries were evaluated. Of them, 32 renal arteries could be assessed with U-MRA. When CE-MRA or DSA was used as the reference standard, nine renal arteries had hemodynamically significant RAS. U-MRA correctly identified eight out of nine arteries as having ≥50% RAS, and correctly identified 22 out of 23 arteries as not having significant RAS, with a sensitivity of 88.8%, a specificity of 95.65%, positive and negative predictive value of 88.8% and 95.65%, respectively, and an accuracy of 93.75%. Renal artery fibromuscular dysplasia (FMD) was observed in the two misclassified arteries. Conclusion U-MRA is a reliable diagnostic method to depict normal and stenotic main renal arteries. U-MRA can be used as an alternative to contrast-enhanced magnetic resonance angiography or computer tomography angiography in patients with renal insufficiency unless FMD is suspected.

Late subcapsular lymphocele in a kidney graft.

min/1.73 m and the proteinuria/creatininuria ratio was 145 mg/mmol. Six weeks after transplantation, the serum creatinine level increased by 20% compared with baseline, and a kidney biopsy was performed (proteinuria 0 g/L). Histopathologic analysis showed mild tubulitis and mild interstitial inflammation (i1, t1, g0, v0, cpt0, ci0, ct0, cg0, mm0, cv0, and ah0), and an immunofluorescence study was negative for C4d, IgM, and C3 deposits, leading to the diagnosis of borderline rejection. None of the nine glomeruli had lesions of membranoproliferative glomerulonephritis. The patient received three pulses of methylprednisolone (500 mg/day). Three months posttransplantation, a protocol kidney biopsy was performed. It contained 14 glomeruli and showed mild interstitial fibrosis and tubular atrophy (i0, t0, g0, v0, cpt0, ci1, ct1, cg0, mm0, cv0, and ah0). An immunofluorescence study was negative for C4d, IgM, and C3 deposits. Six months posttransplantation, the eGFR was 62 mL/min/1.73 m and the proteinuria/ creatininuria ratio was 17 mg/mmol. This is the first reported case of kidney transplantation from a donor with shunt nephritis. As we had hypothesized, the glomerular lesions were reversible and the graft outcome was good, likely because the kidney was extracted from a deleterious immunologic environment of the donor (3). We cannot rule out the potential role of immunosuppressive treatment on this outcome (4). In conclusion, kidneys with diseases induced by immune-mediated extrarenal mechanisms may be considered for transplantation, after histological evaluation in emergency. This strategy could increase the pool of donors.