Key gaps in pathologic reporting for appendiceal mucinous neoplasms: time for universal synoptic reporting?

INTRODUCTION: The prognosis of appendiceal mucinous neoplasms (AMN) is directly related to their histopathology. Existing classification schemes encompass tumors with widely divergent clinical behaviors within a single diagnosis, making it difficult for clinicians to interpret pathology reports to counsel patients on optimal management. We sought to examine pathology reports generated for AMN for inclusion of essential histologic features. METHODS: Pathology reports of appendectomy specimens with a diagnosis of AMN (2002-2015) at our center ("internal") and from referring institutions ("external") were retrospectively reviewed for inclusion of the following 5 essential items: layer of invasion, mucin dissection (low grade neoplasms only), perforation, margins, and serosal implants. RESULTS: Sixty-nine patients were included, 54 with external reports available. Benign/low grade tumors comprised 29.0% and 27.8% of internal and external reports, respectively. Thirty-seven internal reports (53.6%) were signed out by specialist gastrointestinal pathologists. External reports were 66.7% complete for layer of invasion, 26.7% for mucin dissection, 64.8% for perforation, 68.5% for margins, 53.7% for serosal implants, and 18.5% for all items. Internal reports were 75.4% complete for layer of invasion, 40.0% for mucin dissection, 40.6% for perforation, 82.6% for margins, 69.6% for serosal implants, and 17.4% for all items. Eight external (14.8%) and 24 internal (34.8%) reports were synoptic. Synoptic reports were more likely to be complete for all key items both external and internal. CONCLUSION: Most pathology reports are incomplete for essential features needed for management and discussion of AMN with patients. Synoptic reports improve completeness of reporting for these tumors.