Residency Program - Case of the Month

History:

A 69-year-old female returns for follow up regarding her lobular carcinoma in situ (LCIS). She has a long history of LCIS and has been on long-term follow up since 1997. Her annual mammogram of April 2015 was negative with a heterogeneously dense parenchyma, which may limit the sensitivity of mammography.  A subsequent breast MRI revealed a linear non-mass enhancement. The patient denies any new breast symptoms, changes, nipple discharge or other complaints. An MR guided biopsy is performed for further evaluation.

Breast MRI:

Right breast shows moderate background breast parenchymal enhancement. At the 6 to 7:00 position there is a 12 x 5 x 6 mm area of linear non-mass enhancement. This area demonstrates rapid initial enhancement with areas of washout. This area of non-mass enhancement also has low to isointense signal on the T1 and STIR images. No axillary lymphadenopathy (Figure 1).

Figure 1 - Click to enlarge

Microscopic Description:

Lobular acini are distended and distorted by a dyshesive proliferation of cells with small, uniform nuclei. The sections also show multiple foci of solid pattern of architecture and the appropriately organized acini within its immediate vicinity (Figure 2A). The solid pattern with comedo necrosis and laminated microcalcifications are also found (Figure 2B). Some cells show dyshesive growth pattern with vacuoles (Figure 2C). Immunohistochemistry staining shows lack of expression of E-Cadherin in tumor cells (Figure 3).

Figure 2A, 2B, 2C - Click to enlarge

Figure 3 - Click to enlarge

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