Haematophagocytic activity is a salient feature of malignant histiocytic medullary reticulosis. This potency has also been observed as an aberrant property of non-histiocytic malignant cells or as a benign histiocytic process in response to infections or malignancies. We report the case of a patient who presented simultaneously with a limited stage small cell lung carcinoma and a fatal reactive form of histiocytosis. We conclude that such a haematophagocytic syndrome may occur in the setting of small cell lung carcinoma s previously described in other malignancies.