Scintimammographic analysis of nonpalpable breast lesions previously identified by conventional mammography.

BACKGROUND: In randomized trials, screening mammography has led to decreased mortality from breast cancer. However, the low positive predictive value of mammography (i.e., the proportion of patients with a positive test result who actually have breast cancer) results in a large number of unnecessary biopsies. We determined whether scintimammography with technetium-99m-sestamibi is a useful supplemental diagnostic tool for women with nonpalpable breast abnormalities identified by conventional mammography. METHODS: Scintimammography was performed preoperatively on 70 women who were 31-66 years of age (mean age and median age = 51 years). These women had nonpalpable breast abnormalities identified by conventional mammography; subsequently, a needle-localization excisional biopsy of each suspicious lesion was performed. Scintimammographic images were interpreted independently by two nuclear medicine physicians who were blinded to all clinical and pathologic data, and an interobserver variation analysis was performed. RESULTS: Interobserver variation analysis of the scintimammographic findings showed an agreement for breast diagnosis of 97% and a kappa coefficient of 0.90. Comparison of scintimammographic findings and histopathologic results revealed that the sensitivity (proportion of patients with breast cancer who had a positive test result), the specificity (proportion of patients without breast cancer who had a negative test result), the positive predictive value and the negative predictive value (proportion of patients with a negative test result who actually did not have breast cancer) of scintimammography were 56% (95% confidence interval [CI] = 23%-85%), 87% (95% CI = 75%-94%), 38% (95% CI = 15%-68%), and 93% (95% CI = 82%-98%), respectively. Four of nine breast cancers were not detected by scintimammography. CONCLUSION: Because of excellent interobserver agreement, scintimammography provides an objective way of detecting primary breast carcinoma. In view of its low sensitivity and positive predictive value, however, scintimammography is not currently recommended as a screening test in patients with nonpalpable positive mammographic findings.

Scintimammography: the complementary role of Tc-99m sestamibi prone breast imaging for the diagnosis of breast carcinoma.

PURPOSE: To evaluate the complementary role of technetium-99m sestamibi scintimammography in improvement of the sensitivity and specificity of mammography in detection of carcinoma of the breast. MATERIALS AND METHODS: At 5 and 60 minutes after intravenous injection of Tc-99m sestamibi, scintimammograms were obtained in 147 women (age range, 18-73 years; mean age, 47.9 years +/- 10.2 [standard deviation]) with 153 lesions that warranted breast biopsy (102 lesions) or fine-needle aspiration cytologic analysis (51 lesions). There were 113 palpable and 40 nonpalpable lesions. Lesion size on mammograms was 0.8 x 0.6 cm to 15.0 x 11.0 cm (mean, 2.82 cm +/- 1.71 x 2.39 cm +/- 1.56). RESULTS: Scintimammographic findings were true-positive in 47 biopsy-confirmed carcinomas, true-negative in 91 benign lesions, false-positive in 11 lesions with benign histopathologic findings (fibrocystic disease [n = 8] or fibroadenoma [n = 3]), and false-negative in four lesions of infiltrating ductal carcinoma. The sensitivity of scintimammography was 92.2%; specificity, 89.2%; positive predictive value, 81.0%; and negative predictive value, 95.8%. CONCLUSION: The authors conclude that scintimammography is a sensitive test that can improve the detection of breast carcinoma.

Cardiac tamponade as a presentation of malignant thymoma.

Morphologic, cytochemical and immunocytochemical studies of pericardial fluid from a 30-year-old man presenting with cardiac tamponade are described. Based on the results of the immunocytochemical studies and the histologic examination of excised pericardium, a diagnosis of malignant thymoma was made. This is the first documented case in which malignant cells were found in the pericardial effusion in a patient with invasive thymoma. The significance of using a multidisciplinary approach to the study of body fluids is discussed.