BACKGROUND: Small cell carcinoma (SMCC) is rarely diagnosed in urine specimens. Cytologically, this tumor is similar to pulmonary SMCC. However, clinicopathologic correlation may be required to differentiate between primary urinary bladder SMCC and metastatic SMCC from a remote primary or secondary bladder involvement by direct extension of the tumor from nearby organs (prostate, uterus, or ovary). A unique case of a rare pulmonary-type ovarian SMCC, the tumor cells of which were detected in a voided urine specimen, is described herein. CASE: A 79-year-old female presented to the urologic clinic with a history of metastatic SMCC of unknown primary with hematuria. The voided urine specimen examination revealed tumor cells cytomorphologically consistent with small cell neuroendocrine carcinoma. Following cytologic diagnosis, cystoscopic examination and bladder biopsy were performed. The histopathology revealed a widely invasive tumor with a morphology typical of SMCC. The overlying urothelium was unremarkable. By immunohistochemistry, tumor cells were found positive for neuroendocrine markers, EMA and WT-1. The morphologic and immunohistochemical features of the tumor were most consistent with urinary bladder involvement by pulmonary-type primary ovarian SMCC. CONCLUSION: It is justified to think that SMCC cell detection in urine specimens does not necessarily imply their origin from primary bladder malignancy. Performing additional studies may be prudent in order to exclude secondary involvement of the bladder in this tumor as the correct diagnosis has significant clinical implications.
BACKGROUND:Small cell carcinoma (SMCC) is rarely diagnosed in urine specimens. Cytologically, this tumor is similar to pulmonary SMCC. However, clinicopathologic correlation may be required to differentiate between primary urinary bladder SMCC and metastatic SMCC from a remote primary or secondary bladder involvement by direct extension of the tumor from nearby organs (prostate, uterus, or ovary). A unique case of a rare pulmonary-type ovarian SMCC, the tumor cells of which were detected in a voided urine specimen, is described herein. CASE: A 79-year-old female presented to the urologic clinic with a history of metastatic SMCC of unknown primary with hematuria. The voided urine specimen examination revealed tumor cells cytomorphologically consistent with small cell neuroendocrine carcinoma. Following cytologic diagnosis, cystoscopic examination and bladder biopsy were performed. The histopathology revealed a widely invasive tumor with a morphology typical of SMCC. The overlying urothelium was unremarkable. By immunohistochemistry, tumor cells were found positive for neuroendocrine markers, EMA and WT-1. The morphologic and immunohistochemical features of the tumor were most consistent with urinary bladder involvement by pulmonary-type primary ovarian SMCC. CONCLUSION: It is justified to think that SMCC cell detection in urine specimens does not necessarily imply their origin from primary bladder malignancy. Performing additional studies may be prudent in order to exclude secondary involvement of the bladder in this tumor as the correct diagnosis has significant clinical implications.