INTRODUCTION: Recurrent respiratory papillomatosis (RRP) is the most common benign respiratory tract neoplasm in children. Rarely these lesions may undergo malignant transformation, especially after prior radiation therapy for RRP. This is a case of malignant transformation to squamous cell carcinoma of the lung in a woman without prior irradiation after 34 years of RRP.
CASE PRESENTATION: A 34 year-old woman was transferred to our facility from another hospital for evaluation of a serum calcium level of 12.8 mg/dL (normal 8.9–10.1 mg/dL). She described four months of leg pain, muscle aches, and fatigue, as well as a weight loss of 30 pounds. Prior to transfer she had been hydrated and treated with a bisphosphonate. Her past history was significant for hypertension, GERD, and recurrent respiratory papillomatosis diagnosed at the age of 8 months and treated with many interventions including laser therapy, bronchoscopy, and tracheostomy for a short time. She had never received chemotherapy or radiation. She denied any respiratory symptoms except chronic dysphonia. She smoked one pack of cigarettes daily for about ten years, but had recently stopped. A CT scan showed a right paratracheal lung mass, as well as lytic lesions in several ribs, the bony pelvis, and the left femoral head. A biopsy of the pelvic lesion was shown to be consistent with metastatic squamous cell carcinoma. A bronchoscopy was performed which showed mild nonobstructing papillomatous changes to the larynx as well as distal tracheal mucosal erosion. The posterior segmental bronchus of the right upper lobe was obstructed by necrotic appearing material. Biopsies of the mucosal abnormalities and washings were shown to be squamous cell carcinoma. Tissue was not sent for HPV typing. The patient underwent palliative left hip reconstruction with an endoprosthesis, and she was seen by both medical and radiation oncology for palliative therapy. She died three months after presentation.
DISCUSSIONS: Recurrent respiratory papillomatosis is a disease characterized by diffuse recurring papillomas arising in the respiratory tract caused by human papilloma virus. It is the most common benign respiratory tract neoplasm in children, and it is believed that the majority of cases are transmitted vertically during birth. The development of symptoms such as stridor, hoarseness, and the much-feared possibility of airway compromise is bimodal in distribution, occurring at ages <2 and 20–30 years. Most patients require many surgical interventions through life to treat these symptoms. In 80% of cases the papillomas are confined to the larynx. In 5–20% there is involvement in the more distal airways, but the lung parenchyma is involved les than 1% of the time. Rarely (2–3% of cases), malignant transformation to adenocarcinoma or squamous cell carcinoma has been described, usually in patients who have received prior irradiation. The literature reports fewer than twenty cases of malignant transformation in the absence of radiation. These malignancies are typically very aggressive and usually fatal. It is uncertain what role smoking has in this subset of patients.
CONCLUSION: The malignant transformation of RRP to squamous cell carcinoma of the lung in a nonirradiated patient is a rare event, occurring in 2–3% of RRP cases. Our patient developed this fatal complication after almost 34 years of disease.
DISCLOSURE: Matthew McIntosh, No Financial Disclosure Information; No Product/Research Disclosure Information