Discussion
Pancreatic malignancy is the seventh most important cause of cancer
morbidities globally. In 2018, 459,000 new patients reported with this
disease [11]. In future, it is predicted to outstrip breast cancer
in European countries as the third fore-most cause of cancer mortality
[12]. Frequent etiological factors include obesity, nicotine
exposure and elevated blood glucose levels [13,14]. It is perturbing
for the patients diagnosed with pancreatic mass and they are mostly
worried about the type of lesion which makes it essential to counsel
appropriately and conduct rapid medical examination to conclude the
final diagnosis.
Inflammatory pseudotumor is a title devised by Umiker and Iverson in
1954 due to overlapping symptomatic and radiological findings with
pancreatic malignancy [15]. It is a benign, unusual entity which
tends to involve all locations in the body but most frequently present
in orbit and the lung. Inflammatory pseudotumors may be solitary or
multitudinous with a blend of neutrophils and lymphocytes along with an
uneven extent of fibrosis, myofibroblastic spindles, necrosis, and
formation of granulomas [16-18].
ITP is known to be associated with autoimmune diseases, trauma and
fibrosarcoma [19-21]. Other conditions such as IgG4 associated
sclerosing disease where T-cell and IgG4 positive plasma cells attack
multiple tissues. The manifestations include autoimmune pancreatitis,
cholecystitis, tubulointerstitial nephritis, IPT, prostatitis,
interstitial pneumonia and sclerosing cholangitis along with
lymphadenopathy. Few patients have reported IgG4-related IPTs in the
absence of autoimmune pancreatitis [22, 23].
IgG4-related disease presents as a tumor like swelling involving the
organs it affects. The type 1 form of IgG4-related disease depicts a
type of autoimmune pancreatitis. Patients frequently show up with an
acutely developing mass, painless obstructive jaundice, and diffuse
organomegaly. Such a presentation can be misunderstood for pancreatic
cancer [24]. IgG4-related disease has a criteria of a serum IgG4
level > 135 mg/dL with around 40% of IgG+ plasma cells
being IgG4+ (>10 cells/high-power field of biopsy sample).
The following criterion is valuable, yet not adequately sensitive to
diagnose type 1 IgG4-related autoimmune pancreatitis [25].
An international agreement was set up by the International Association
of Pancreatology regarding the differential diagnosis of the two
particular types of autoimmune pancreatitis (types 1 and 2). This can be
differentiated on the basis of 5 criteria: (1) imaging changes in the
pancreatic parenchyma and duct; (2) serology (for IgG4 and IgG
antinuclear antibodies); (3) extrapancreatic involvement; (4) histology;
and (5) response to corticosteroid therapy [26]. Radiological
evaluation plays a crucial role in closely studying and identifying
these lesions. However, the histopathological review is thought to be a
much-needed step in landing on a definitive diagnosis [27]. CT scans
might show a variable appearance of such inflammatory tumors, from
hypoattenuated to isoattenuated depending on the muscle and few
calcifications might be there in the liver, pancreas, or stomach
pseudotumors. MRI images can likely differ; after the introduction of
the contrast heterogeneous enhancement is seen. However, this still
cannot differentiate these lesions from a true pancreatic carcinoma
[19].
The definitive diagnosis of these lesions depends on the
histopathological outcomes; with some specimens being attained
post-surgical resection. This accounts for around 5–10% of the
pancreatectomies. Surgical resection of the tumor is believed to be
therapeutic despite the chances of possible morbidity and post-surgical
complications. Some data indicate corticosteroids, nonsteroidal
anti-inflammatory drugs, and thalidomide to have curative role and
curtail the tumor burden [27, 21]. Recurrence rate is calculated to
be around 18–40% [27]. Such recurrent lesions can be associated
with local invasion. Resection of such lesions is indicated since they
might possess a malignant transformation potential [21]. Literature
suggests few occurrences of spontaneous regression [27,21].
IPTs are a rarity and a frequent incidental finding during routine
radiological examination. They can also be encountered while
investigating for non-specific clinical features or a detected mass from
an unknown source. Definite diagnosis depends on the radiological and
histological assessment that can be attained post-surgical resection or
biopsy. Surgical resection is the first line of treatment if the
diagnosis is not clear or was not previously done and it is curative in
most cases. Surgical resection is the first line of treatment in case
the diagnosis is unclear or wasn’t done in the first place. Surgical
resection is curative in most cases.