Removed Benign Breast Lump, Pain In The Elbow. Breast Cancer?

My sister (around 40 yrs old and a mother of 4) found a lump on her left breast last month. FNAC showed that it is benign (the FNAC report says: Smears studied show good cellularity consisting of duct etichelial cells arranged in cohesive clusters. In some of the clusters there is mild to moderate anisokaryosis and nuclear overlapping. background shows fibrofatty fragments, occasional bare nuclei, cyst , macrophages proteinacious fluid mixed with blood. Proleferative lession of the breast with severe duct hyperplasia; C1-Benign ). She has pain in her left arm and found it difficult to raise her hand, but no pain or swelling under in the armpit. She was operated yesterday (to remove only the lump). The doctor removed a round lump of around 2 cm diameter and there was cyst/fluid present inside the lump. We are yet to get the biopsy result of the lump. After the surgery my sister felt less pain in the left arm but some pain remains in her elbow . Will it be a case of breast cancer . If so, what should be the next course of action, please help. W. Kamei