Multimodal Treatment Approach for Mixed Neuroendocrine-Non-Neuroendocrine Neoplasms of the Gallbladder: A Patient with a Favorable Survival Outcome.

Mixed neuroendocrine-non-neuroendocrine neoplasm of the gallbladder (GB-MiNEN) is an exceptionally rare and aggressive tumor with no established treatment guidelines. We herein present the case of a 53-year-old woman with GB-MiNEN who was treated with irinotecan and cisplatin therapy, which led to a significant tumor reduction and subsequent conversion surgery. Despite a later recurrence, multimodal therapy extended survival for over two and a half years. This case underscores the potential benefit of conversion surgery combined with systemic chemotherapy, thus suggesting that multimodal treatment may improve the outcomes of GB-MiNEN. Our findings highlight the need for further studies to optimize the treatment strategies for this rare malignancy.