Fine needle aspiration cytology of collecting duct carcinoma of the kidney: report of a case with distinctive features and differential diagnosis.
BACKGROUND
The relative rarity of collecting duct carcinoma (CDC) of the kidney in conjunction with a lack of distinctive cytologic features is a diagnostic challenge for any cytopathologist when dealing with such a tumor on fine needle aspiration cytology. In previous cytologic reports, CDC is not well characterized, and the features overlapped with those of high grade renal cell carcinoma (RCC). Because of the differences in behavior and treatment from conventional RCC, it is important to attempt to diagnose this tumor correctly.


METHODS
The cytologic findings of CDC in a 56-year-old woman were distinctive and not emphasized previously. Ductal/tubular differentiation, prominent desmoplastic stromal component, neutrophilic infiltration and the presence of numerous tubules ranging from benign to dysplastic and frankly malignant were notable features of this tumor. The expression of high-molecular-weight cytokeratin and Ulex europaeus agglutinin helped to confirm the diagnosis.


CONCLUSIONS
The present case highlights several characteristic cytologic features that were useful in suggesting the diagnosis of CDC on fine needle aspiration cytology. Immunohistochemical stains, such as high-molecular-weight cytokeratin and lectin, helped to confirm the diagnosis.
Sarode
Venetia R
VR
Department of Pathology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9073, USA. venetia.sarode@utsouthwestern.edu
Islam
Shahid
S
Wooten
Dennis
D
Watumull
Lori Meril
LM
Molberg
Kyle
K
Ashfaq
Raheela
R
D014408:Biomarkers, Tumor / Q000378:metabolism; D044963:Biopsy, Fine-Needle; D002277:Carcinoma / Q000473:pathology*; D002292:Carcinoma, Renal Cell / Q000473:pathology; D002467:Cell Nucleus / Q000473:pathology; D003593:Cytoplasm / Q000473:pathology; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000517:prevention & control*; D004847:Epithelial Cells / Q000473:pathology; D005260:Female; D006801:Humans; D007633:Keratins / Q000378:metabolism; D007680:Kidney Neoplasms / Q000473:pathology*; D007685:Kidney Tubules, Collecting / Q000473:pathology*; D008875:Middle Aged; D009504:Neutrophils / Q000473:pathology; D017154:Stromal Cells / Q000473:pathology
D014408:Biomarkers, Tumor; D007633:Keratins