Duodenum (Psammomatous) Somatostatinoma

Grading / Staging / Report

WHO 2010 recommends the following grading scheme, but it is not clear if it applies to somatostatinomas

Proposed grading scale based on proliferation

Mitotic counts based on 50 hpf
Ki67 % based on 500-2000 cells
If discrepant, use higher grade
Scale proposed by European Neuroendocrine Society (ENETS)
- Carcinoids / neuroendocrine tumors may be G1 or G2
- G3 is definitional for high grade neuroendocrine carcinoma
Progression from G1/2 to G3 is quite rare
- G3 appears to be a separate process

Grading/Staging References

Rindi G, Klöppel G, Couvelard A, Komminoth P, Körner M, Lopes JM, McNicol AM, Nilsson O, Perren A, Scarpa A, Scoazec JY, Wiedenmann B. TNM staging of midgut and hindgut (neuro) endocrine tumors: a consensus proposal including a grading system. Virchows Arch. 2007 Oct;451(4):757-62.
Rindi G, Klöppel G, Alhman H, Caplin M, Couvelard A, de Herder WW, Erikssson B, Falchetti A, Falconi M, Komminoth P, Körner M, Lopes JM, McNicol AM, Nilsson O, Perren A, Scarpa A, Scoazec JY, Wiedenmann B; and all other Frascati Consensus Conference participants; European Neuroendocrine Tumor Society (ENETS). TNM staging of foregut (neuro)endocrine tumors: a consensus proposal including a grading system. Virchows Arch. 2006 Oct;449(4):395-401.

Staging