Examples of hTERT interpretation. a Numerous malignant cells are seen, more than half demonstrating positive nuclear staining. The cells have recognizable and intact cytoplasm on the counterstain and are morphologically compatible with urothelial cells; thus, it is appropriate to interpret them as hTERT positive. The presence of cytoplasmic staining in some of these cells does not invalidate the result. b Two cells (lower left) have nuclear staining and recognizable, intact cytoplasm. The cells are morphologically compatible with urothelial cells; a mature squamous cell (upper right) acts as an internal negative control. c A cluster of bacteria stain positively by hTERT and approximate the size of a urothelial cell nucleus. The stain was not interpreted as positive if a cell’s cytoplasm was not clearly seen. d–f Numerous positive-staining bacteria are present in the background, stuck to mature squamous cells. In cases where positive-staining inflammatory cells and/or bacteria obscured the preparation, the test was considered noninterpretable. f Despite positive-staining bacteria at the bottom of the field, a positive urothelial cell is clearly seen in the center of the field. In such instances, cases could be interpreted as positive.