Rosen's Breast Pathology, 4e

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Chapter 33

more than the normal thickness that varies from 1 ± 0.2 mm over the upper outer quadrant to 1.5 ± 0.4 mm over the ­areola. 269 Despite diffuse dermal involvement by tumor em­ boli, direct invasion into the skin with cutaneous ulceration is found only in advanced cases. Paget disease of the nipple is uncommon, although the nipple is often retracted. 269 When present, Paget disease is typically accompanied by intraductal carcinoma of major lactiferous ducts. Microscopic Pathology “Primary inflammatory carcinoma” is usually a manifes­ tation of infiltrating duct carcinoma that is almost always poorly differentiated 268,269 (Fig. 33.34). Tumor emboli are usually encountered throughout the breast, but this may rarely be an inconspicuous feature. Many of the vascular spaces containing carcinoma are devoid of red blood cells and are considered to be lymphatics. However, channels of similar structure and caliber containing erythrocytes and tu­ mor emboli are also encountered, especially in patients with extensive vascular and lymph node involvement. Hence, a distinction between blood vessel and lymphatic emboli is often difficult in hematoxylin and eosin (H& E) stained sections.

FIG. 33.33.  Inflammatory carcinoma, mastectomy. Inva- sive carcinoma is present throughout the breast. There is peau d’orange change in the skin.

6 cm in greatest diameter). 268 The majority of the carcinomas were central, or they were large enough to occupy virtually the entire breast. Diffuse induration of the mammary paren­ chyma was palpable, and the skin was visibly thickened, mea­ suring 2 to 8 mm thick (averaging 4 mm). This is substantially

FIG. 33.34.  Primary inflammatory carcinoma. A: The pri- mary tumor is an infiltrating, poorly differentiated ductal carcinoma. B: Clusters of carcinoma cells lie in a dilated lymphatic channel. C: Carcinomatous emboli in a vascular channel with red blood cells.