Nasolacrimal Duct Malignancy or IgG4- Related Disease? A Curious Case Report of a Nasal Vestibular Mass and Review of the Literature.

IgG4-related disease (IgG4-RD) is a fibro-inflammatory condition associated with tumefactive lesions at multiple sites. IgG4-RD was initially recognized in 2001 in a case of autoimmune pancreatitis. However, the disease was not limited to the pancreas but involved other organs such as the bile ducts, lacrimal glands, lymph nodes and salivary glands. IgG4-RD is rarely seen with an estimated incidence of 0.2 to 1/100.000 as reported in Japan, but with minimal to no incidence data have been published in Western countries. We hereby report a case of an IgG4-related mass arising from the nasolacrimal duct, masquerading as a sinonasal mass.