Cytomorphologic features and differential diagnosis of neoplasms with small cell features in liquid-based urinary tract cytologic specimens

The presence of small atypical cells in liquid-based UTCy should raise the suspicion of underlying malignancy involving the urinary tract. Cell clustering, nuclear molding, and hyperchromasia are helpful hints for the diagnosis of small cell carcinoma and the presence of small atypical cells with prominent nucleoli raises the possibility of lymphoma or melanoma.