Contributed by Anuradha Murty Dharbhamulla, MD, MSc, MIAC, Dilip Gupta, MD, MIAC and Manju E. Nath, MD
Published on line in October 2000
A fine needle aspiration (FNA) biopsy was attempted along with a core biopsy.
Fig. 2 FNA cytology showing loosely cohesive groups of myoepithelial cells with abundant granular eosinophilic cytoplasm, bland nuclei with fine chromatin. Scattered bare nuclei in the background are also seen (Papanicolaou stain, 20X)
Fig. 3 Core biopsy showing the well demarcated lesion (H&E, 4X)
Fig. 4 Benign epitheloid smooth muscle cells & fibroblasts, separated by bands of collagen (H&E, 40X)
Fig. 5 Cells with abundant cytoplasm, round to oval nuclei & prominent nucleoli (H&E, 40X)
Fig. 6 Positive staining with CD34 immunostain (10X)
Fig. 7 Negative staining with cytokeratin AE1/AE3 im
The cytology revealed smears with loosely cohesive groups of round or oval to spindled epithelioid cells. The cytoplasm was finely granular, pink and fibrillar. The nuclei were ovoid to spindle shaped without atypia (Fig. 02). The nuclear chromatin was uniform with inconspicuous nucleolus. The background revealed few ductal epithelial cells and foam cells, without mucoid material or inflammatory cells.
The core biopsy showed a fairly well demarcated lesion composed of benign epithelioid smooth muscle cells and fibroblasts (Figs. 03 & 04). The cells had abundant amount of finely vacuolated cytoplasm, round to oval nuclei and prominent single nucleoli (Fig. 05). The cells were positive for smooth muscle actin, SMA (Sigma), vimentin (Dako), desmin (Dako), CD 34 (Dako) (Fig. 06) and negative for AE1/3 (Boehringer Mannheim) (Fig. 07), epithelial membrane antigen, EMA (Dako), and S-100 (Dako) immunostains. All immunostains were performed with LSAB-2 detection kit and run on Shandon immunostainer.
Segmental mastectomy was subsequently performed which yielded a 1.4 x 0.7 x 0.7 cm firm, tan nodule. Microscopic examination revealed a cellular, well circumscribed lesion consisting predominantly of polygonal cells arranged in alveolar groups separated by thin bands of collagen. The cellular morphology was similar to that seen in the core biopsy. Focal areas of infiltration by lymphocytes and hemosiderin-laden macrophages were seen. No mitosis, hemorrhage or necrosis was observed. The surrounding compressed breast tissue was unremarkable.
Immunoperoxidase study using antibodies against actin, vimentin, desmin, keratin, EMA, S100 and CD34 were performed, which yielded results similar to those observed in the core biopsy.