Metastatic renal cell carcinoma presenting as a breast mass in a woman with history of primary breast cancer

Abstract

Metastatic extramammary breast lesions are rare. Differential diagnosis with primary breast lesions may be difficult. The following case describes the clinical course of a woman with a breast lesion as initial presentation of a renal cell carcinoma. Case reportA 83-year-old caucasian woman developed a ductal breast carcinoma in the right breast (pT2 N0 M0) in 1995. She underwent a tumorectomy and a right axillary lymph node dissection followed by radiotherapy. She had been treated with tamoxifen during five years.The patient had 11 years of followup of her breast carcinoma without severe abnormalities apart from 2 clinically palpable lumps of scar tissue in the right breast which were twice biopsied and histologically negative.In June 2007, the patient was examined and found to be in a good general condition on a routine gynaecological consultation. Clinically, she had a satisfying heart and lung auscultation. Clinical breast examination remained normal. Her laboratory work-up only demonstrated an elevated lactate dehydroge-Mammography in June 2007 demonstrated a single well-marginated opacity in the axillary tail of the right breast with a diameter of 6 mm (Fig. 1A,B) and a similar lesion of 7 mm and calcifications (Le Gal type 2) in the left breast ( Fig. 2A,B). pathologies could not be made. Metastasis of the former breast cancer could not be ruled out. Core needle biopsy (CNB) was performed on the lesion in the right breast.In July 2007 CNB (Fig. 4) showed morphologically a metastasis of a renal cell carcinoma (RCC). Immunohistological characterisation indicated a positive staining for CD 10 suggestive of RCC of the clear cell type (Fig. 5) and a negative for cytokeratine CK7 and CK 20.Next, computer tomography (CT) of the thorax and the abdomen illustrated several lung metastasis and a large hypervascular mass in the left kidney, suggestive of RCC (Fig. 6). Due to the patient's age, the significant comorbidity, and the Ultrasound investigation (Fig. 3) visualised a regular circumscribed nodular hyporeflective lesion in the axillary tail of the right breast. The lesion was evaluated with fine needle aspiration cytology (FNAC). The left side only showed some lymph nodes.On FNAC epithelial cell populations were found. A differentiation between benign and malignant JBR-BTR, 2011, 94: 330-332. Metastatic extramammary breast tumours are uncommon and differential diagnosis with primary breast carcinoma may prove to be difficult. We report a case of a metastasis of a renal cell cancer in the breast in a woman with a history of primary breast cancer. On follow-up of her breast carcinoma, a lump was detected via mammography and ultrasound. Core needle biopsy revealed a metastatic extramammary lesion originating from an asymptomatic renal cell carcinoma. We conclude that the diagnosis of metastasis to the breast from extramammary tumours is important to avoid unnecessary surgery and insure proper treatment of the primary disease. METASTATIC RENAL CELL CARCINOMA PRESENTING AS A BREAST MASS IN A WOMAN WITH HISTORY OF PR...