International prospective evaluation of scintimammography with technetium-99m sestamibi: interim results.

OBJECTIVE: The purpose of this study is to evaluate the validity and reliability of scintimammography with technetium-99m (99mTc)-labeled sestamibi as an adjunct radiodiagnostic agent in the diagnosis of breast cancer. METHODS: This is a multicenter prospective cohort clinical trial that was initiated in June 1999 and will terminate May 2001. All patients with a physical or mammographic finding visiting any of the participating clinics are enrolled in the study. Patients who are younger than 18 years, pregnant, not willing to sign the consent form, or who have undergone an invasive procedure on the breast 30 days or less before scintimammography are excluded. At the time of the first interim report, 633 patients had been recruited from six Canadian centers. To date complete data have been collected for 530 patients. RESULTS: The mean (SD) age of the patients is 56 (12) years with a range between 24 and 85. There were 122 (23%) of the women in the sample who were postmenopausal and 36 (7%) who were perimenopausal. Breast density was graded as dense for 127 (24%), normal for 260 (50%), and fatty for 138 (26%). Of the 530 women in the study 156 (29%) had a palpable mass at physical examination. The mammographic results were classified as 76 (14%) breast imaging reporting and data system (BIRADS) 5, 60 (11%) BIRADS 4, 70 (13%) BIRADS 3 and the remaining BIRADS 2 or 1. The scintimammography results were positive for 118 (23%) of the patients and negative for 412 (78%). The histopathology showed malignant breast disease for 66 (12.5%) of the patients in the sample. Sensitivity and specificity of scintimammography for the detection of breast cancer was estimated 90.9% and 87.5%, respectively. A positive predictive value (PPV) of 50.8% with a negative predictive value of 98.5% and an accuracy of 87.5% were calculated. The PPV is interpreted as the posttest probability of disease given a positive test result. In this sample the pretest probability of disease would be best estimated by the prevalence of disease, which is equal to 12.5%. A positive scintimammography result would change the estimated probability to 51%, which is equivalent to a 400% change from the pretest value. Therefore a positive scintimammography result significantly increases our ability to predict the presence of malignant disease in this population. CONCLUSION: The interim results of the present study suggest that scintimammography with 99mTc-sestamibi is accurate and potentially useful as an adjunct to mammography for the detection of breast cancer.

Association of breast cancer with meningioma.

We report a case of meningioma subsequently developed in a patient with bilateral breast carcinoma, which was originally thought to be single brain metastases. A brief review of the literature is presented with emphasis on the unique association between the two neoplasms, which suggests a possible hormonal relationship. The knowledge of this association is important in the differential diagnosis of patients with breast cancer who develop central nervous system manifestations.

99mTc Tetrofosmin imaging in breast tumours.

Eighty-five women, 18 to 80 years of age, with palpable breast lumps were studied 1-4 days before surgery in order to evaluate 99mTc Tetrofosmin imaging for the detection of malignant breast tumours. Intravenous injection of 99mTc Tetrofosmin was followed by 3 min planar images at 5-60 min postinjection. In the latter 57 patients, planar imaging was preceded by a dynamic study of 20x5 sec images. The myocardium was always included in the field of the left breast. Count rates in suspicious areas were compared with normal tissue areas in the same and the opposite breast and with myocardial counts. Data analysis showed that 77 of the 85 scan results were in agreement with the histological findings; six scans were false negative and two false positive for malignancy. The sensitivity of the method was 90.32% and the specificity 91.30%, with a positive predictive value of 96.55%. We conclude that breast scanning with 99mTc Tetrofosmin may play an important role in the detection of breast malignancies.

Bilateral Paget's disease of the breast.

A rare case of metachronous bilateral Paget's disease of the nipple is presented. The occasional failure of routine follow-up to detect certain tumours until biologically advanced and the value of patient observations are mentioned.

Generalized cutaneous hyperpigmentation in hairless mice induced by topical dimethylbenzanthracene.

The skin of hairless (Ng/Bln) mice topically treated with dimethylbenzanthracene (DMBA) was investigated by light microscopy, histochemistry, electron microscopy and autoradiography in order to gain some insight into the mechanisms by which the DMBA-induced cutaneous hyperpigmentation is mediated. The results of the present study indicate that this phenomenon is due to the DMBA-induced stimulation of both the tyrosinase system and the mitotic activity of dopa-inactive dormant melanocytes.