Cancer de mama oculto: dos casos clínicos analizados según el concepto actual / Occult breast cancer: Report of two cases

ABSTRACT

Occult breast cancer is expressed as a metastatic axillary lymph node without clinical or imaging evidence of a primary tumor in the breast. The old concept involved non palpable tumors. Its incidence is low, representing only 0.3 to 1 percent of all breast cancer cases. The search for the primary tumors is performed with mammography, whose sensitivity is low, ranging from 0 to 56 percent. Several studies have shown a higher sensitivity of magnetic resonance imaging, ranging from 85 to 100 percent, to detect occult lesions. The treatment of isolated axillary metastases of breast cancer is controversial. An axillary dissection is recommended. If there is a suspicious image, a radiosurgical or stereotaxic biopsy should be done. However, in patients without radiological lesions in the breast, the tendency is not to perform a radical mastectomy as previously recommended, since the primary tumor will not be found in the surgical specimen in two thirds of cases. A superior and external quadrantectomy or exclusive radiotherapy should suffice. An expecting behavior is not recommended as a therapeutic alternative. Treatment should be complemented with hormonal therapy or chemotherapy. The literature suggests that prognosis is better than stage II, with a ten years survival ranging from 50 to 71 percent. We report two patients with a well defined occult breast cancer and based on them, a review of the subject is attempted. Considering its prognosis, physicians should be aware of this uncommon and difficult to diagnose disease.