From Pathology Education Instructional Resource
Cytology
Resident Questions
- Pancreatic Endocrine Neoplasm
- Include Islet cell tumor and pancreatic carcinoid tumors
- Approximately 5% of pancreatic neoplasms
- Most commonly seen in both male and female adults between 40-60 years old but can occur at any age
- Small (1-5 cm) well circumscribed lesion may look cystic on imaging
- Commonly seen in the tail of the pancreas
- Can be part of Multiple Endocrine Neoplasia-1, von Hipple-Lindau disease, Neurofibromatosis type 1, Tuberous Sclerosis Complex
- Cellular smear with singly dispersed uniform cells
- Loosely cohesive or discohesive uniform cells
- Cells are uniform, plasmacytoid with abundant finely granular cytoplasm
- Background is clean
- Occasional pleomorphism can be seen
- Round/oval bland cells with salt and pepper chromatin
- Acinar cell carcinoma
- Clusters, acinar groups and single cells with abundant granular cytoplasm and prominent nucleoli
- Lack salt and pepper chromatin
- Positive staining for trypsin, chymotrypsin and alpha-1-antichymotrypsin
- Negative for neuroendocrine markers
- Solid Pseudopapillary Neoplasm
- May see hyaline globules and clear cytoplasmic vacuoles
- Branching papillary clusters with distinct central fibrovascular cores, but this can be seen in PEN too
- Positive for vimentin, CD10, beta catenin, neuron specific enolase, CD56
- Negative for keratin markers
- Plasmacytoma
- Look for a perinuclear hof and clock face chromatin
- Positive staining for CD138
- Negative for neuroendocrine markers
- Islet cell hyperplasia
- Difficult/ impossible to distinguish from islet cell tumor by cytology alone
- Melanoma
- Can see melanin pigment in the cytoplasm but not always
- Melanoma cytomorphology can be quite diverse
- Positive for MART-1, HMB45, MITF
- Negative for neuroendocrine markers
- Neuroendocrine markers
- CD56
- Synaptophysin
- Chromogranin
- Cytokeratin
- TTF-1
- Markers specific to peptide production
