Case 2. Malignant adenomyoepithelioma in the breast with metastases to the lung. a-f The breast tumour. a HE, (b) CK5, (c) p40, (d) S100, (e) HE, peripheral part of the tumour suspicious for invasion, (f) p40, peripheral part of the tumour. g-l One of the metastases to the lung. g HE, central part of the tumour, (h) HE, peripheral part of the tumour, (i) CK5, (j) p40, (k) S100, (l) CK7. Note the CK7-positive reactive alveolar epithelium (positive also for TTF-1, not shown) leading to a papillary appearance at the periphery of the tumour. All images x10 objective.