A 42 year old female was referred to the Breast Clinic for assessment of a palpable right breast lump. She had detected the breast lump six weeks previously during routine self examination and did not complain of any mastalgia, nipple discharge, skin changes or systemic symptoms. She had no personal or family history of breast cancer and had never used the oral contraceptive pill (OCP) or hormone replacement therapy. Clinical examination revealed a non-tender, mobile 2 cm solid mass in the upper outer quadrant of the right breast. Mammography and Ultrasonography confirmed the presence of a 2 cm solid mass in the right upper quadrant (Figures ). Core biopsy demonstrated fibroadipose tissue with stromal calcification. Given the clinical and pathological findings the patient opted for surgical excision of the lesion. Gross examination of the specimen revealed a well circumscribed firm nodule measuring 2.5 × 2.0 cm. The cut surface was firm and tan-gray in colour, with a whorled appearance. Microscopically the tumour shows a benign epithelial component with elongated, branching ducts and cellular stroma. The stroma was composed of cells with giant nuclei some of which are multi-nucleated. Mitosis of these cells was not seen (Figures ). The stromal cells stained negative for the Estrogen and Progesterone receptors (ER, PR respectively) Pancytokeratin (AE1/3 & CAM 5.2), Muscle Specific Actin, S100 and desmin, and stained positive for Vimentin; a general mesenchymal marker and suggestive of cells of myofibroblastic origin (Figures ). The conclusive diagnosis was that of a fully excised benign fibroadenoma, with multinucleated giant cells throughout its stroma. She made an uneventful postoperative recovery and follow-up has shown no recurrence of the lesion.
Radiology images from 2 cases presenting with a breast mass. a. Case 1. Mammogram of right breast. b. Case 1. Ultrasound of right breast. c. Case 2. Mammogram of left breast. d. Case 2. Ultrasound of left breast.
Figure 2 Microscopy of breast core biopsies. a. Case 1 (H&E stain, × 200). b. Case 1 (H&E stain, × 200). c. Case 1 (H&E stain, × 400). d. Case 2 (H&E stain, × 200). e. Case 2 (H&E stain, × (more ...)
Figure 3 Immunohistochemical stains on core breast biopsy tissue. a. Case 1: Pancytokeratin. b. Case 1: SMA. c. Case 1: Vimentin (arrow marks multinucleated giant cells in stroma). d. Case 2: Pancytokeratin. e. Case 2: SMA. f. Case 2: Vimentin (arrow marks multinucleated (more ...)
The second case is that of a 48 year old lady referred to the Breast Clinic with a two month history of a left breast lump and mastalgia. She denied nipple discharge, nipple inversion or skin changes. She had no relevant past medical history, had never used the OCP and had no family history of breast cancer. On examination, a 1.5 cm tender solid mass was palpable in the upper inner quadrant of the left breast. Ultrasonography revealed the presence of a number of small benign cysts with a single solid lobulated mass lesion at 12 o'clock measuring 17 mm in diameter (Figure ). Mammography confirmed the presence of a smooth mass measuring 2 cm in diameter in the retro-areolar region of left breast (Figure ).
Ultrasound guided tru-cut biopsy was performed. Histological analysis demonstrated cores and fragments of fibroadenomatous breast tissue, with numerous uniformly giant and multi-nucleated cells intermingled with fibroblasts throughout the stroma, (Figures ).
Immunohistochemistry staining of these giant cells was negative again for ER & PR status, pancytokeratin (AE1/3 & CAM 5.2) and muscle specific actin (Fig ) as well as for S100 protein and desmin. They showed only positivity with vimentin (Figures ). No malignant changes were seen and a diagnosis of benign fibroadenoma of the left breast with a multi-nucleated giant cell stroma was made. The patient declined surgical excision of the lesion.