Pseudoneoplastic lesions: general considerations

Intrapancreatic Accessory Spleen: A Diagnosis Not to Forget!

A 69-year-old male patient was incidentally diagnosed with a 5-mm lesion in the pancreatic tail by endoscopic ultrasound (EUS). After contrast-enhanced EUS and EUS-elastography, all imaging features were highly suggestive of a benign pancreatic solid lesion such as an intrapancreatic accessory spleen (IPAS) or a benign neuroendocrine tumor. Interposition of the splenic artery precluded EUS-guided fine-needle aspiration (FNA). When an asymptomatic pancreatic mass is detected, IPAS diagnosis should be considered, and, if EUS-FNA is infeasible, contrast-enhanced EUS and EUS-elastography are useful tools to differentiate a pancreatic benign lesion as IPAS from a malignancy, with avoidance of unnecessary surgery.

Pathological features of IgG4-related sclerosing disease

PURPOSE OF REVIEW

The spectrum of IgG4-related systemic disease (IgG4-RSD) continues to widen. At most of the sites involved by this condition, the clinical presentation can mimic neoplasm. Pathologic assessment of small biopsies can be critical to proper management. This review summarizes the histologic features of IgG4-RSD and the role of immunohistochemistry of IgG4 in the diagnosis.

RECENT FINDINGS

The review period saw further expansion of the list of sites putatively involved by IgG4-RSD, with new, or more detailed, entries related to lung, lymph nodes, stomach, and thyroid. A tentative consensus was reached on the issue of subtypes of autoimmune pancreatitis. The role of immunohistochemistry for IgG4 as an adjunct to the diagnosis of IgG4-RSD was further clarified.

SUMMARY

Sclerosing lymphoplasmacytic inflammation at almost any site can represent a manifestation of IgG4-RSD. There are several histologic features that can suggest the diagnosis. Immunohistochemistry for IgG4 is a useful diagnostic test to further support the diagnosis.