case_images: PMC3699953_01
case_images: Case 1: A - A bright-red, lobulated plaque with an oozing-surface on
  the left nipple and areola (original presentation in 2004); B -
  Bright erythematous, eczematoid plaque with a slightly mamillated surface and
  ill-defined hyperchromatic margins (year 2010); C - Psoriasiform
  hyperplasia with diffuse clear-cell change of keratinocytes in the Malpighian
  layer and fusion of rete ridges (H-E, original magnification 100x); D
  - Clear cells stained in red, basal cell layer spared (PAS, original
  magnification 100x); E - Clear cells failed to stain with PAS after
  diastase digestion (PAS-diastase, original magnification 100x); F -
  Intense expression of EMA by clear cells (EMA immunoperoxidase, original
  magnification 100x)
case_images: abd-88-0084-g01.jpg
case_images: PMC3699953_01_abd-88-0084-g01.jpg
case_images: f01
case_images: Dermatological examination revealed a well-demarcated, bright-red, lobulated plaque with an oozing surface on the nipple and areola measuring 4x4 cm (Figure 1A). During a follow-up consultation in 2010, the persistent lesion showed a much larger size of approximately 10x8 cm, a slightly raised, mamillated, wet, and scarcely squamous surface, and some expansion to the surrounding skin (Figure 1B). Although a diagnosis of nipple eczema had been clinically favored, a diagnosis of CCA was proposed after a new biopsy with routine PAS/PAS-diastase and immunohistochemical stainings was performed, as well as a reassessment of recuts from the first biopsy block (Figures 1C-F).
case_images: PMC3699953_02
case_images: Case 2: A - Somewhat raised, infiltrated plaque on the left
  nipple/areola with eroded, wet surface and well-defined margins; B -
  Elongated, fusioned, club shaped rete ridges with numerous clear cells. Note
  papillary-dermal edema, elongated capillaries, and inflammatory cell infiltrate
  (H-E, original magnification 100x); C - Eroded epidermis, congestive
  capillaries, and erythrocyte extravasation beside an acantotic epidermis with
  intense clear-cell change; D - Neutrophils scattered among clear
  cells (H-E, original magnification 400x); E - Mixed interstitial and
  perivascular inflammatory cell infiltrate composed of lymphocytes and numerous
  eosinophils (H-E, original magnification 400x); F - Intense
  expression of EMA by clear cells (EMA immunoperoxidase, original magnification
  100x)
case_images: abd-88-0084-g02.jpg
case_images: PMC3699953_02_abd-88-0084-g02.jpg
case_images: f02
case_images: On examination, a 2.0 x 2.5 cm erythematous, infiltrated, erosive plaque with distinct borders and scant clear fluid secretion was observed on the left nipple and areola (Figure 2A). Given the previous experience with case #1 , a clinical diagnosis of CCA was considered and finally confirmed by histology and immunohistochemistry (Figures 2B-F).
case_images: PMC3699953_03