Collecting duct renal carcinoma is a rare variant of renal cell carcinoma (RCC), accounting for about 1% of renal epithelial malignancies. 1,2 This is an aggressive variant of RCC with early lymph node and distant metastasis being common. 1,3 They occur in a wide age range, including young adults, with a mean age of 55 years. 1,4,5 Their histological appearance has been well described 1,2 with tumours showing predominantly a tubular or tubulopapillary growth pattern with mainly high-grade nuclei in a desmoplastic stroma. Their cytological morphology is less characteristic, with mainly small case reports in the literature describing fine-needle aspiration (FNA) and imprint cytology of the kidney tumour, metastasis and of desquamative urine cytology. 3-6 The features that are described include: tubules, sheets and papillary fragments of tumour. The nuclei are high grade with hyperchromatic chromatin and nucleoli. Cytoplasm varies in amount, is delicate, eosinophilic and occasionally can be vacuolated. 3,5,6 Other features include fibrous tissue fragments, ramifying vascular network, hobnail appearance, basal membrane-like substance in epithelial clusters and neutrophilic infiltrate. 3,5,6 In aspirates of the renal primary, there can be an admixture of both normal tubules, tubules with dysplastic epithelium and frank malignant tubules. 5 We present a 26-year-old man who had a left nephrectomy for a collecting duct carcinoma (Fig. 1). He subsequently received chemotherapy. Following surgery, the patient had to be started on haemodialysis for chronic renal failure due to malignant hypertension. He presented 6 months later with bright red spot haemoptysis for the past 3 weeks. He had no systemic complaints and no weight loss. Erythrocyte sedimentation rate (ESR) was 9 (normal), two sputum cultures showed no growth and two Zeihl Neelson stains were negative for mycobacteria. CT scan showed a right main bronchus tumour but no parenchymal infiltration (Fig. 2). At bronchoscopy, there was external compression of both the right middle and lower lob bronchi (Fig. 3). Transbronchial fine-needle aspiration biopsy (FNAB) was performed using a 22G Wang needle. One needle pass was very cellular yielding an epithelial malignancy. The patient subsequently started haemorrhaging and no further FNAB or biopsies could be performed.The cytology showed an adenocarcinoma, with morphology not typical of a high-grade adenocarcinoma of the lung. The features were more in keeping with a lowgrade (well-differentiated) adenocarcinoma. The carcinoma showed small cellular groups, micropapillary-like (Fig. 4) and numerous tubular structures (Fig. 5). Looselying cells were readily apparent. The nuclei ranged from medium to large in size, with irregular nuclear membranes, finely granular chromatin and small nucleoli. The cytoplasm was scant in amount with occasional vacuolated cells (Fig. 6).These features by themselves do not correspond to a specific diagnosis of a collecting duct carcinoma. As transbronchial FNAB usually do not yield large tissue ...