Invasive ductal carcinoma NOS

Invasive ductal carcinoma NOS can only be diagnosed when the histological features of lobular carcinoma and the special types of ductal carcinoma e.g. medullary, have been excluded. Usually, it is associated with a high grade and poor prognosis.

Macroscopically it may exhibit:

• usually well-circumscribed
• rarely greater than 3-4 cm
• stony hard and gritty consistency - 'scirrhous'
• areas of calcification

Microscopically there may be:

• dense fibrous stroma
• diffusely scattered nests or cords or tumour cells
• evidence of vascular or neural invasion
• cells:
  • polygonal
  • compressed
  • uniform small, dark nuclei few mitoses