Fine needle aspiration cytology with the aid of immunocytochemistry on cell-block confirms the diagnosis of solid pseudopapillary neoplasm of the pancreas

Introduction To determine the diagnostic efficacy of fine needle aspiration cytology (FNAC) in cases of pancreatic solid pseudopapillary neoplasm (PSPN) with emphasis on the cytomorphological features and to evaluate the contribution of immunocytochemistry on FNAC cell-block (CB) in cases of PSPN. Methods It is a retrospective study in which ultrasound-guided FNAC of pancreatic lesions diagnosed as PSPN between years 2009 and July 2019 were reviewed along with cytohistological correlation. Immunocytochemistry on CB was performed, wherever required. Results A total of 16 patients with a cytological diagnosis of PSPN of the pancreas were identified. The most common cytological findings were characteristic branching pseudopapillary fragments with central thin, delicate capillaries associated with the amorphous myxoid substance, surrounded by tumour cells with mild pleomorphism. Immunocytochemistry was performed on CB of six cases. The tumour cells revealed nucleocytoplasmic positivity for beta-catenin, cytoplasmic positivity for vimentin, membranocytoplasmic positivity for CD10 and nuclear positivity for progesterone receptor in all the cases, while they were negative for chromogranin, CD56, pan-cytokeratin and epithelial membrane antigen. The resected histopathological specimen was available in 10cases, and all were confirmed as PSPN. Conclusion Although PSPN has a characteristic cytomorphology, cell-block immunocytochemistry on FNA material confirms the diagnosis in problematic cases and excludes other pancreatic tumours, thus helping in appropriate management.

Automated summary

This retrospective study evaluated the diagnostic efficacy of FNAC in cases of PSPN from 2009 to July 2019, finding that PSPN has characteristic cytomorphology and immunocytochemistry on cell-blocks can help confirm the diagnosis and exclude other pancreatic tumors.