Bone Marrow Metastasis from a Pancreatic Neuroendocrine Tumor: Morphologic Mimicry of Acute Leukemia.

BACKGROUND

Pancreatic neuroendocrine tumors (pNETs), rare neoplasms originating from pancreatic islet cells, have limited morphological descriptions in smears following bone marrow metastasis.

METHODS

This study reports a rare case of pancreatic neuroendocrine tumor (pNET) with bone marrow metastasis, comprehensively evaluated through an integrated diagnostic approach encompassing clinical assessment, bone marrow aspiration with morphologic analysis, flow cytometry, cross-sectional imaging, and lymph node biopsy.

RESULTS

Bone marrow smears revealed scattered blast-like cells with fine chromatin and granular cytoplasm, mimicking acute myeloid leukemia, but these cells were negative for myeloperoxidase. Flow cytometry identified CD45-/CD56+ cell population lacking hematopoietic markers. Imaging identified a pancreatic mass with wide-spread bone destruction, and lymph node biopsy confirmed metastatic pNET via positive staining for chromo-granin A and synaptophysin.

CONCLUSIONS

This case highlights the diagnostic challenges posed by pNET bone marrow involvement and emphasizes the importance of integrating morphology, immunophenotyping, and clinical data to avoid misdiagnosis and ensure timely, appropriate treatment.