Plate 4 continues the illustration of the proposed neoplastic progression from ALA (Figure 4A) through DCIS (Figures 4A through 4C) and LCIS (Figures 4D and 4E) to invasive carcinoma (Figures 4F to 4H).

A. Figure 25. Subgross preparation of mammary gland of a premenopausal woman in her 5th decade, illustrating a lobule (ALA) completely replaced and distended by carcinoma-in-situ of the classical ductal cytological type (DCIS). Geographically isolated formations such as this argue strongly for origin of DCIS in lobules rather than in ducts, as formerly believed. Note the dark central necrosis in the acini.

B. Figure 26. Subgross preparation of mammary gland of a menopausal woman in her 6th decade. No lobules are visible. The duct system is solidly filled with DCIS. Note the very dark central necrosis. The necrotic cellular remnants are sufficiently calcified to appear as "castings" on x-ray mammograms. The ducts illustrated traverse the full thickness of the 2-3 mm thick mammary slice.

C. Figure 27. Histological differences between DCIS of the comedo pattern with central necrosis (left) and DCIS of the cribriform (micropapillary) pattern (right).

D. Figure 28. Subgross preparation of mammary gland of menopausal woman in her 6th decade. Normal lobules to the left. The four enlarged lobules in the right half of the drawing are typical of some cases of lobular carcinoma-in-situ (LCIS). The affected lobules are enlarged with acini more or less uniformly distended by cells.

E. Figure 29. Histology preparation of LCIS shows acini distended with atypical cells which also occupy portions of the adjacent duct.

F. Figure 30. Subgross slice of human breast through the nipple region reveals a stellate cellular density measuring about 2 cm in diameter. This is typical of scirrhous carcinoma (classical infiltrating duct carcinoma). The carcinoma is located in the center of the mammary layer and has not yet attached itself to the overlying skin or the underlying pectoralis fascia. The mammary layer shows the classical "dysplastic pattern" of dense fibrous tissue in which are embedded numerous lobules, many of which are likely to be pathological. The fibrous dysplastic tissue appears as "ground glass" on x-ray mammograms.

G. Figure 31. Subgross preparation of a small 3-4 mm infiltrating duct scirrhous carcinoma. Three acini, possibly representing remnants of the lobule (ALA) of origin are seen to the right of the infiltrating carcinoma. An ALA is observed at lower left.

H. Figure 32. High power histology of infiltrating duct carcinoma. The upper right shows a normal duct for comparison. The lower left has cribriform pattern of carcinoma which may still be in-situ. The infiltrating nests of large cancer cells have enlarged hyperchromatic and pleomorphic nuclei.