Paget's disease is an intraepithelial carcinoma of the nipple or in extramammary body zones such as the anogenital area or the axila. Mammary and extramammary Paget disease share many common clinicopathological features but also show several differences. Sir James Paget first described Paget disease of the breast in 1874; he reported the chronic eczematous disease on the skin of the nipple and the areola with an associated intraductal carcinoma of the underlying mammary gland. Mammary Paget disease is usually observed in women over 40, but it also may occur in men. Mammary Paget’s disease represents approximately 1% to 3% of breast neoplasms. 
          The condition develops insidiously as an erithema of the nipple. Advanced lesion frequently presents as an unilateral, ovoid or polycyclic erythematous, scaly plaque involving the nipple and/or the areola; the plaque has sharply and slightly elevated limits.  Retraction and/or ulceration of the nipple are often noted and pain, burning, and pruritus are frequently reported by patients.
Proper recognition of mammary Paget disease is required to initiate appropriate workup. Early dermatologic consultation and a biopsy of the lesion are necessary for accurate diagnosis; regular mammographic examination aid in early detection of invasive breast cancer.  
          Differential diagnose is made with nipple eczema, erosive adenomatosis, psoriasis, dermatophyte infection, Bowen disease, drug eruption, nodular cutaneous amyloidosis, etc. 
Surgical treatment involving radical or modified mastectomy is appropriate therapies for patients with Paget disease with underlying invasive breast carcinoma. Conservative management includes local nipple excision, wedge resection of the underlying breast and radiotherapy. 
         We report the case of a 62 year old woman who presented with an erythematous plaque on the nipple which spread onto the areola and to the skin of the right breast. The borders of the lesion were sharply marginated and the surface was crusty and thickened. Retraction of the nipple was present in both breasts; it was noticed by patient in teenager. The anamnesis revealed a history of fibrocystic mastosis with no other significant medical issues. Usually laboratory investigations were normal.
Biopsy of the lesion was performed and revealed numerously large cells with large, basophilic nuclei (“Paget cells”). Clinical and anamnestic findings corroborated with histological analysis helped us to diagnose the patient with Paget disease.  
The patient was referred to the oncology service for further investigation regarding underlying breast disease and appropriate treatment.

MAMMARY PAGET’S DISEASE - CASE REPORT