Metastatic rectal neuroendocrine tumor presenting as an inguinal mass: A case report and review of literature

INTRODUCTION: Neuroendocrine tumors (NET) are a heterogeneous group of rare carcinomas that most often manifest along the gastrointestinal tract. Some of these tumors have the ability to secrete vasoactive peptides and hormones. PRESENTATION OF CASE: The present report describes the case of a previously healthy 52-year old man who presented with a painful right inguinal mass. Upon surgical exploration, a lymph node metastasis of a high-grade NET was found. Further investigations revealed a rectal NET with pulmonary, pelvic and penile metastases. The patient was treated with 6 cycles of carboplatin and etoposide. Although initial follow-up imaging after 3 cycles of chemotherapy revealed stable disease, there was progression of the metastases after completion of systemic treatment. Second and third-line chemotherapy regimens were instituted along with pelvic and whole-brain radiation therapy extending the patient’s survival to 18 months after the initial diagnosis. DISCUSSION: This case highlights the aggressive nature high-grade NETs as described in the current literature. Treatment modalities of colorectal NETs include local excision for non-metastatic disease and systemic palliative chemotherapy for advanced disease. However, there are no controlled trials in favor of palliative chemotherapy. CONCLUSION: Rectal NETs are rare tumors which often have an atypical presentation or present in advanced stages. Currently, surgical options exist for local disease while treatment modalities for more advanced disease is still under investigation.