Abstract. Breast metastasis from extra-mammary malignancy is rare. An incidence of 0.4-1.3% has been reported in the literature. The primary malignancies most commonly metastasizing to the breast are leukemia, lymphoma and malignant melanoma. We present a case of metastasis to the breast from a pulmonary adenocarcinoma, diagnosed concomitantly with the primary tumor. A 43-year-old female presented with dyspnea and a dry cough of 3 weeks' duration. A subsequent chest radiograph revealed a massive pleural effusion. Additionally, on physical examination, a poorly defined mass was noted in the upper outer quadrant of the right breast. The patient underwent bronchoscopy, simple right mastectomy and medical thoracoscopy. Following cytology, histology and immunohistochemistry, primary lung adenocarcinoma with metastasis to the breast and parietal pleura was diagnosed. Histologically, both the primary and metastatic anatomic sites demonstrated a micropapillary component, which has recently been recognized as an important prognostic factor. Although the patient received chemotherapy, she succumbed to her condition within 8 months. Accurate differentiation of metastasis from primary carcinoma is very important as the treatment and prognosis of the two differ significantly.
IntroductionThe National Cancer Institute of the USA estimates that, based on current rates, 12.7% of females born today will be diagnosed with breast cancer in their lifetime (1). Although primary breast cancer is the most common malignancy of adult females, metastatic involvement of the breast is rare, with a reported frequency of 0.4-1.3% in clinical series (2-5). Despite its rarity, metastatic breast disease is an significant diagnostic clinical problem, as its treatment differs greatly from that of primary breast cancer. In 1907, Sitzentfrey was the first to publish a case of ovarian carcinoma metastatic to the breast (6). To date, a wide variety of malignancies have now been reported to metastasize to the breast and according to the literature, the most common primary tumors are melanomas and haematological malignancies (5-7). The lung is the most common cancer site in terms of incidence and mortality; however, there have only been a few published cases of pulmonary carcinomas metastasizing to the breast (8-12). Carcinomas with micropapillary components have been reported at several anatomical sites, including the breast, urinary bladder, ovary and major salivary glands (13). Micropapillary components are being increasingly recognized as prognostic predictors in lung adenocarcinomas and according to many studies, this may be a manifestation of aggressive behaviour (14,15). We report the case of a patient with breast metastasis from a pulmonary adenocarcinoma characterized by a micropapillary pattern and diagnosed in conjunction with the primary tumor. Written informed consent was obtained from the patient for publication of this case report and accompanying images.
Case reportA 43-year-old, non-smoking housewife presented to the Emergency Departme...