Zuska disease is an eponym for

Ans. is 'a' i.e., Squamous metaplasia of lactiferous ducts in breast Squamous Metaplasia Of Lactiferous Ducts:* Squamous metaplasia of lactiferous ducts is known by a variety of names, including recurrent subareolar abscess, periductal mastitis, and Zuska disease.* Women, and sometimes men, present with a painful erythematous subareolar mass that clinically appears to be a bacterial abscess. In recurrent cases, a characteristic fistula tract often tunnels under the smooth muscle of the nipple and opens onto the skin at the edge of the areola.* Many women have an inverted nipple, most likely as a secondary effect of the underlying inflammation.* More than 90% of the afflicted are smokers. It has been suggested that a relative deficiency of vitamin A associated with smoking or toxic substances in tobacco smoke alter the differentiation of the ductal epithelium.* The key feature is keratinizing squamous metaplasia of the nipple ducts. Keratin shed from these cells plugs the ductal system, causing dilation and eventually rupture of the duct. An intense chronic granulomatous inflammatory response develops once keratin spills into the surrounding periductal tissue.* With recurrences, a secondary anaerobic bacterial infection may supervene and cause acute inflammation.* Simple incision drains the abscess cavity, but the offending keratinizing epithelium remains and recurrences are common.* In most cases, en bloc surgical removal of the involved duct and contiguous fistula tract is curative. If secondary bacterial infection is present, antibiotics also have a therapeutic role.