Oncocytic carcinoid tumor of the lung: a case report of diagnostic pitfall in filter membrane preparation of bronchial washings.
BACKGROUND
Oncocytic carcinoid tumor of the lung is a rare variant of pulmonary carcinoid. This report describes the morphologic appearance of this rare tumor on filter membrane preparation along with potential pitfalls.


METHODS
A 49-year-old woman presented with cough and expectoration. On chest radiograph a mass lesion was seen in the upper zone of the right lung. Bronchial washings were sent for evaluation. On filter membrane (Millipore) preparation of bronchial washing the possibility of a non-small cell carcinoma, possibly squamous, was suggested. Right upper lobectomy was subsequently performed and a histologic diagnosis of oncocytic carcinoid given. The cytomorphologic features of this tumor on the Millipore preparation were reviewed.


CONCLUSIONS
Differential diagnosis of oncocytic carcinoid should be kept in mind while assessing cytologic material when tumor cells show abundant granular cytoplasm and prominent nucleoli. Oncocytic carcinoid also must be differentiated from oncocytoma and granular cell tumor. Immunocytochemistry and electron microscopy are useful in confirming the diagnosis.
Arora
Raman
R
Cytology Laboratory, Department of Pathology, All India Institute of Medical Sciences, and Sir Gangaram Hospital, New Delhi, India.
Mathur
Sandeep R
SR
Aron
Manju
M
Verma
Kusum
K
Iyer
Venkateswaran K
VK
Arora
Vinod K
VK
Sharma
Meher C
MC
D018893:Bronchoalveolar Lavage / Q000379:methods*; D001992:Bronchoalveolar Lavage Fluid / Q000166:cytology; D002276:Carcinoid Tumor / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D002289:Carcinoma, Non-Small-Cell Lung / Q000175:diagnosis; D002294:Carcinoma, Squamous Cell / Q000175:diagnosis; D003581:Cytodiagnosis / Q000379:methods; D003937:Diagnosis, Differential; D003951:Diagnostic Errors / Q000517:prevention & control; D005260:Female; D006801:Humans; D008175:Lung Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery; D008851:Micropore Filters; D008875:Middle Aged; D013902:Radiography, Thoracic