A 78‐year‐old woman presented with 1 month of weakness and falls. She had had a 50‐pound weight loss over the previous year. Previously, she was diagnosed with breast cancer and treated with a lumpectomy, chemotherapy, and radiation. She moved to Texas following Hurricane Katrina and was lost to follow‐up. She had a 62‐pack‐year history of smoking. She had decreased strength in both lower extremities. Otherwise, the physical exam was unremarkable. Chest x‐ray was suspicious for 2 masses in the left lung. Chest CT confirmed 2 masses (5 × 6 and 2.3 × 2.6 cm) and many lymph nodes and sub‐pleural nodules in both lung fields. There were multiple nodular densities in the right breast. Ultrasound revealed 2 lesions in the right breast. Ultrasound‐guided biopsy revealed moderate to poorly differentiated squamous cell carcinoma with squamous pearl formation, without any evidence of mammary tissue. Tumor cell markers were consistent with a primary pulmonary etiology. Biopsy of the lung mass revealed scattered squamous cells that expressed p63. The patient was diagnosed with primary squamous cell lung carcinoma metastatic to the right breast.
Breast and lung masses are both frequently encountered in internal medicine. Breast cancer is the most commonly diagnosed malignancy in Louisiana women, whereas lung cancer, on the rise, is the second most prevalent. In patients with a previous history of breast cancer, there is a greater risk for treatment‐related second primary carcinoma, especially in patients who receive radiation therapy. The reported patient received radiation therapy as a part of her breast cancer treatment 9 years earlier. In addition, she had a significant smoking history, putting her at a greatly increased risk for a second primary malignancy, namely, lung cancer.
In general, metastases to the breast from extramammary sites are rare. Shetty, Ahmed, and Khan discovered only 431 cases of extramammary carcinoma metastatic to the breast over a course of 138 years. Of these cases, lung cancer was the second most likely primary site to metastasize to the breast. In addition, a Taiwanese case report from 2008 reported the incidence of squamous cell carcinoma metastasizing to the breast. When faced with a patient with a breast mass, physicians cannot overlook the possibility that the mass could be metastatic from an extramammary site. In addition, it is important when evaluating new lesions in breast cancer patients to take into account smoking and treatment history. New primary lesions and metastases thereof should be on the differential.
M. Sheen ‐ none
To cite this abstract:Sheen M. When Tumor Is the Rumor (The Converse Can Also Be True). Abstract published at Hospital Medicine 2011, May 10-13, Dallas, Texas. Abstract 392. Journal of Hospital Medicine. 2011; 6 (suppl 2). https://www.shmabstracts.com/abstract/when-tumor-is-the-rumor-the-converse-can-also-be-true/. Accessed April 10, 2020.