Table of Contents
Definition / general | Essential features | Terminology | ICD coding | Radiology images | Case reports | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Electron microscopy description | Sample pathology report | Differential diagnosis | Board review style question #1 | Board review style answer #1Cite this page: Gonzalez RS. Neuroendocrine tumor with sarcomatous differentiation. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/pancreaspensarcomatous.html. Accessed March 29th, 2024.
Definition / general
- Well differentiated neuroendocrine tumor with poorly differentiated myosarcomatous component
Essential features
- Extremely rare lesion (two cases reported in English literature)
- Lesion may transition from neuroendocrine to sarcomatous component or may have two discrete admixed components
Terminology
- Both reported cases use outdated term islet cell tumor, as they were published in 1989 and 2001
ICD coding
- ICD-10: C25.4 - malignant neoplasm of endocrine pancreas
Case reports
- 61 year old woman with 11 cm pancreas mass (Mod Pathol 2001;14:1187)
- Patient with widely metastatic lesion with rhabdomyosarcomatous component (Am J Surg Pathol 1989;13:422)
Microscopic (histologic) description
- Lesion is primarily composed of typical well differentiated neuroendocrine tumor
- Sarcomatous component may have rhabdomyosarcomatous features or may show spindled cells with enlarged nuclei arranged in bundles
- Sarcomatous component is admixed with neuroendocrine component but transition may be gradual or abrupt (with sarcomatous component appearing as discrete nodules)
Microscopic (histologic) images
Positive stains
- Neuroendocrine markers (synaptophysin, chromogranin) in neuroendocrine component
- Desmin in sarcomatous component
Electron microscopy description
- Z lines and thick filaments (if rhabdomyosarcomatous component)
Sample pathology report
- Pancreas and duodenum, Whipple procedure:
- Pancreatic neuroendocrine tumor with focal sarcomatous differentiation (see synoptic report and comment)
- Comment: Sarcomatous differentiation is extremely rare in pancreatic neuroendocrine tumors. Immunohistochemical stains for synaptophysin and chromogranin are positive in the typical neuroendocrine component and the Ki67 index in that component is approximately 2.7% (WHO grade 1).
Differential diagnosis
- Leiomyosarcoma:
- Most common sarcoma of pancreas
- Would not demonstrate neuroendocrine component
Board review style question #1
A neuroendocrine tumor of the pancreas with a sarcomatous component would be most likely to show what sort of differentiation within that component?
- Angiosarcomatous
- Leiomyosarcomatous
- Liposarcomatous
- Osteosarcomatous
Board review style answer #1
B. Leiomyosarcomatous. Additionally, leiomyosarcoma is the most common primary sarcoma of the pancreas.
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Reference: Neuroendocrine tumor with sarcomatous differentiation
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Reference: Neuroendocrine tumor with sarcomatous differentiation