The first case of IgG4-related disease (IgG4-
RD) was first described as autoimmune pancreatitis
(AIP) with elevated serum IgG4 concentration
in 2001 [10]. In 2008, Takato et al. [11]
first presented a case of isolated IgG4-RLD
which was without the complication of AIP,
manifested as ground-glass opacities (GGO)
and reticular shadows on chest CT. Some scholars
considered that isolated IgG4-RLD need to
be classified as a new separate entity among
IgG4-RD [2, 11], but there is no consensus concerning
whether it is an isolated forms of IgG4-
RLD or forms with AIP.