RESUMO
OBJECTIVE: We describe the novel case of a patient presenting with pulmonary mucosa-associated lymphoid tissue lymphoma (pMALToma) synchronous with metastatic prostate adenocarcinoma. MATERIALS AND METHODS: We report the clinical, laboratory, radiological and histological findings of the above patient. RESULTS: While the patient's metastatic prostate adenocarcinoma responded well to chemo-radio-hormonal therapy, a persistent area of lung consolidation was noted and further investigated, leading to the diagnosis of concurrent pMALToma. CONCLUSION: It is important to pursue further investigation when there appears to be persistent change or altered disease response in malignancy if there is evidence for disease response elsewhere, as there may be two synchronous primary cancers. LEARNING POINTS: This is a novel case where pulmonary mucosa-associated lymphoid tissue lymphoma (pMALToma), a rare disease entity, presented synchronously and asymptomatically in a patient with metastatic prostate adenocarcinoma.From an instructive errors perspective, it is important to consider synchronous primary malignancy and pursue further investigations, as appropriate, when there appears to be persistent change or altered disease response if there is evidence for disease response elsewhere.