Rectum to Medulla Oblongata: Colorectal Cancer Metastasizing to the Brainstem

Metastasis with colorectal cancer (CRC) is commonly seen in the liver, lungs and peritoneal cavity. Brainstem involvement with CRC is not studied with no prior reported cases. We report a case of CRC, admitted for apneic spells and dry cough and later found to have metastasis to the left anterolateral medulla oblongata. A 28-year-old male, with a past medical history of asthma, and colorectal adenocarcinoma metastatic to the brain, presented to the emergency department with complaints of a dry cough, altered mental status and shortness of breath. He was seen at urgent care before and was given a week of oral levofloxacin for presumptive pneumonia without any relief. Physical examination was concerning for stridor with clear lung fields. MRI brain showed previously noted post-operative right frontoparietal craniotomy changes and a new 9 x 8 x 8 mm ring-enhancing intra-axial lesion centered at the left anterolateral medulla oblongata indicative of brainstem metastatic disease. The patient was intubated for airway protection and underwent a suboccipital craniotomy for resection of the left pontomedullary mass, and histopathology was positive for metastatic adenocarcinoma, colorectal primary with hemorrhagic necrosis. He had a tracheostomy placed post multiple failed extubation trials and a gastrostomy tube for oral feeds. Goals of care were addressed with the patient and family, and a decision was made for home hospice.