Solitary pulmonary papillomas are rare tumors in adults. The glandular papilloma is the rarest subtype. We describe a case of solitary glandular pulmonary papilloma and review the current literature in this disease.
A 65-year-old Caucasian woman was found to have a 9 mm lesion in the right lower lobe by a commercial CT screening examination 1.5 years prior. The patient deferred a short-term follow-up and/or diagnostic evaluation. Now, a chest CT demonstrated a 16 mm nodule in the right lower lobe with irregular margins. She was asymptomatic. The patient had a remote cumulative 25 pack-year smoking history. Her physical examination and laboratory parameters were unrevealing. A positron emission tomography showed an isolated focus of increased FDG activity (SUR 4.8) corresponding to the location of the nodule on the chest CT. A bronchogenic carcinoma was strongly suspected. Therefore, the patient underwent a resection of the nodule with an intraoperative histologic examination, which showed glandular pulmonary papilloma without evidence of malignancy.
In adults a solitary pulmonary papilloma represents a rare benign neoplasm accounting for only 0.38% of all lung tumors and 7-8% of all benign lung tumors. Unlike multiple papillomatosis seen in young people, frequently in children, the solitary pulmonary papilloma commonly appears in the 5th and 6th decades of life. The clinical manifestations are: hemoptysis, dyspnea, wheezing, post-obstructive pneumonia, or clinically asymptomatic radiographic abnormalities. Three histologic types have been recognized: squamous papillomas, glandular papillomas, and mixed squamous and glandular papillomas. Squamous papillomas and mixed papillomas are predominantly seen in male smokers. Squamous papillomas are the most common type of solitary pulmonary papillomas and are strongly associated with human papilloma virus. Squamous papillomas demonstrate a high rate of malignant transformation ranging from 8% to 40%. The risk of transformation increases with cigarette smoking, age greater than 40, and infections with HPV serotype 16 or 18. The glandular papilloma, as seen in our patient, represents a very rare subtype of pulmonary papillomas. Only 13 cases have been reported in English literature from 1954 to the present. Eight were found in males and 5 in females. Eleven of the 13 cases presented with endobronchial disease and associated clinical symptoms. Only 1 patient presented as an incidental peripheral pulmonary nodule. As opposed to the squamous and the mixed papillomas the glandular papilloma tends to occur in non-smokers and in an older patient population. In contrast to the squamous papillomas, there have been no reports of malignant transformation of glandular papillomas though the number of reported cases remains limited. No recurrence has been reported after either lobectomy (6 patients) or bronchoscopic removal (4 patients).
Solitary pulmonary papillomas are rare benign neoplasms. Among the papillomas the glandular subtype is the rarest. Patients usually present with endobronchial lesions; a peripheral location, as seen in our case, is uncommon. In contrast to squamous papillomas, malignant transformation has not been reported for glandular papillomas. Endoscopic ablation for endobronchial locations and limited surgical resection of peripheral lesions seem to be justified based on the current evidence in the medical literature. Table:
Patient characteristics, symptoms, histology, treatment and follow-up information on reported cases of glandular papilloma including our case report
AuthorAgeSexSmokeLocationSymptomsEpithelial cell typeTreatmentFollow upAshmore8
62MYesRLLPneumoniaCiliated columnarBronchoscopic removalNo recurrence after 18moSpencer10
60M-LLL-Cuboidal multilayered nonsquamousLobectomy-59M-RLL-Cuboidal multilayered nonsquamousBronchoscopic removalNo recurrence after 2.5 yrs-----Ciliated cuboidal--26F-LUL-Columnar+ cuboidalLobectomy-Roviaro7
57MYesRLLRecurrent pneumoniaCiliated columnar/cuboidalLobectomy-Basheda11
74MYesRLLHemoptysisColumnar-Lost to follow upFlieder3
74MNoLULHemoptysisColumnarLobectomyNo recurrence after 1.5 yrs65FNoR mainWheezing, Chest tightnessCiliated columnarBronchoscopic removalDied with no evidence of disease after 5yrs69FNoLULHemoptysisCiliated columnarLobectomyNo recurrence after 11yrs68MNoLULIncidentalColumnarLobectomyNo recurrence after 4yrsSari12
47MNoRLLHemoptysisMultilayered columnarBronchoscopic removalNo recurrence after 12moOur case65FYesRLLIncidentalCiliated multilayered columnarWedge resection-
R. Tanaka, None.