Pseudomyxoma peritonei (PMP) is a rare mucinous disease most commonly arising from the appendix. Pleural involvement arising from established PMP is seen in a small number of cases. Combined cytoreductive surgery and hyperthermic intrathoracic chemotherapy is the treatment of choice when managing intra-thoracic PMP. In cases of recurrence, surgical intervention may be technically challenging and carry higher rates of complications, morbidity, and mortality. Bromelain and acetylcysteine (BromAc®) is a novel treatment modality that has demonstrated mucolytic properties. When injected directly into mucinous disease, it facilitates tumour dissolution and allows it to be aspirated. It has recently been tested in the treatment of inoperable peritoneal mucinous disease, with an acceptable safety profile and positive objective response. Here we describe the first two cases of BromAc® administered directly into pleural adenomucinosis, with striking differences in response between the two patients likely due to differences in tumour hardness.