Tubular carcinoma is a type of breast carcinoma which is usually small in size and is characterized by an excellent prognosis. Histology shows infiltrating, angular to comma-shaped tubular structures consisting of relatively small, uniform cells with round, bland, low-grade nuclei, usually with a prominently desmoplastic stroma.
Cytological diagnostic features
- Mild to moderate cellularity
- Cohesive clusters with angular shapes and tubular patterns
- Uniform, mildly atypical epithelial cells
- Stromal bipolar nuclei and fibro-myxoid fragments may be present
Because of the relatively small, bland nuclei and low epithelium-to-stroma ratio, this type of breast carcinoma tends to be under-diagnosed in FNA specimens. Furthermore, because of the usual small size of the tumour, FNA often samples both the tumour and the adjacent benign breast tissue, resulting in the presence of myoepithelial cells in some cases, which can be a confounding feature. Histological biopsy confirmation or frozen sections can be advised in these cases.