Dynamic magnetic resonance imaging of the breast: Comparison of gadobutrol vs. Gd-DTPA. / Resonancia magnética dinámica de mama: estudio comparativo de gadobutrol y Gd-DTPA.

OBJECTIVE: To compare the pharmacokinetic profile of gadobutrol versus Gd-DTPA in dynamic contrast-enhanced MRI (DCE-MRI) in patients with breast cancer. Secondary objectives included comparing the safety profiles and diagnostic efficacy of the two contrast agents for detecting additional malignant lesions. MATERIAL AND METHODS: This retrospective observational study included 400 patients with histologically confirmed breast cancer; 200 underwent DCE-MRI with Gd-DTPA (Magnevist®) and 200 underwent DCE-MRI with gadobutrol (Gadovist®). Pharmacokinetic parameters and signal intensity were analyzed in a region of interest placed in the area within the lesion that had greatest signal intensity in postcontrast sequences. We compared the two groups on pharmacokinetic variables (Ktrans, Kep, and Ve), time-signal intensity curves, and the number of additional malignant lesions detected. RESULTS: The relative signal intensity (enhancement) was higher with gadobutrol than with Gd-DTPA. Washout was lower with gadobutrol than with Gd-DTPA (46% vs. 58,29%, respectively; p=0,0323). Values for Ktrans and Kep were higher for gadobutrol (p=0,001). There were no differences in the number of histologically confirmed additional malignant lesions detected (p=0,387). CONCLUSIONS: Relative enhancement is greater with gadobutrol, but washout is more pronounced with Gd-DTPA. The number of additional malignant lesions detected did not differ between the two contrast agents. Both contrasts are safe.

[Sentinel lymph node biopsy in cutaneous non-melanoma malignancies]. / Biopsia selectiva de ganglio centinela en tumores cutáneos no melanoma.

PURPOSE: To assess the feasibility of the Sentinel lymph node biopsy (SLNB) technique in cutaneous non-melanoma malignancies. MATERIALS AND METHODS: Nine patients were retrospectively evaluated performing a scintigraphy with 99mTc-nanocolloid. On the day of the surgery, an initial dynamic study and static images were obtained. The first drainage station visualized was considered the sentinel node (SLN). The SLN position was marked on the skin and after a correct localization in the surgical field with a gamma probe the SLN was obtained. Patients of this study have been followed up for 8 to 48 months. RESULTS: Lymphoscintigraphy detected the sentinel node in 88,8 % of our studies (the SLN was not observed in a patient with a Merkel's tumour on the back). The SLN was identified intraoperatively in those patients with positive imaging. Those cases without scintigraphic demonstrated migration were also not found intraoperatively. Histopathological analysis of the SLN showed non metastatic disease and none patient developed metastases or local recurrence in the monitoring period. CONCLUSIONS: Sentinel node biopsy can be applied to certain cutaneous non-melanoma malignancies. In patients with unclear drainage and to avoid unnecessary lymphadenectomy, the technique offers clear advantages. In our study the SLN analysis was related to the clinical progress. A large number of patients should be examined to truly assess the benefit of this technique in this kind of malignancies and to determinate when the technique must be performed.

[Metaplastic carcinoma of the breast: magnetic resonance and radiophatologic correlation]. / Carcinoma metaplásico de mama: resonancia magnética y correlación radiopatológica.

OBJECTIVES: To review our radiological experience in metaplastic carcinoma together with the clinical and histopathologic findings. METHODS AND MATERIALS: Eight cases of histologically confirmed metaplastic carcinoma of breast were reviewed. Imaging findings from US, mammography and MRI, and immunohistochemistry results from preoperative biopsy were assessed. Conventional prognostic factors, chondral differentiation markers, striated and straight muscle markers, neural markers, cytokeratin, vimentin and intermediate filaments were determined. RESULTS: Eight patients aged ranged from 41-72 years. Metaplastic carcinoma presented as a palpable nodule in five cases, as a nipple retraction in ones case, and was discovered as an incidental mammographic finding in two. Mammographic appearance was a round, high-density nodule, measuring 10-50 mm, with variable margins in seven patients. One had architectural distortion. In three there were calcifications. Skin and nipple retraction appeared in one. On sonographic examination nodules were ill defined and showed low heterogeneous echogenicity. On MRI, T2-weighted images showed a relatively well-defined mass with high signal intensity. In the dynamic study, all showed contrast uptake, with signal-time intensity curves similar to those of infiltrating carcinoma of the breast. Histopathologic study found one squamous-cell, one sarcomatous, three chondroid, one giant-cell, one spindle-cell, and one acantholytic carcinoma, all of which were of high histologic grade. CONCLUSIONS: Metaplastic carcinoma should be included in the differential diagnosis of a nodule presenting with high density and variable margins on mammography, low heterogeneous echogenicity and ill defined margins on sonography, and hyperintense at T2 with malignant enhancement at MR. Immunohistochemical assessment is mandatory for the final diagnosis. The radiologist can suggest this particular subtype of tumour.

Hepatocellular carcinoma presenting as portal thrombosis with intrabiliary growth: US and MR findings.

We present an unusual case of hepatocellular carcinoma presenting as massive portal vein thrombosis with progression to the intrahepatic bile ducts without demonstrable primary hepatic tumor. Ultrasound, magnetic resonance, and percutaneous transhepatic cholangiography findings are described. The histologic diagnosis was achieved by means of percutaneous forceps biopsy of the endobiliary mass.