CT findings of malignant change in recurrent respiratory papillomatosis

Primary Lung Tumors in Children: Radiologic-Pathologic Correlation From the Radiologic Pathology Archives

Primary lung tumors in children are rare, with a narrow range of diagnostic considerations. However, the overlapping imaging appearances of these tumors necessitate attention to key discriminating imaging and pathologic features. In the neonate and infant, the important considerations include pleuropulmonary blastoma (PPB), infantile fibrosarcoma, and fetal lung interstitial tumor. Among these tumors, imaging findings such as air-filled cysts in type 1 PPB and homogeneously low attenuation of fetal lung interstitial tumors are relatively specific. Key pathologic and genetic discriminators among this group of tumors include the DICER1 germline mutation found in PPB and the t(12,15)(p13;q25) translocation and ETV6-NTRK3 fusion gene seen in infantile fibrosarcoma. Primary lung tumors in older children include inflammatory myofibroblastic tumors (IMTs), carcinoid salivary gland-type tumors of the lung, recurrent respiratory papillomatosis, and other rare entities. IMT, a spindle-cell proliferation with inflammatory elements, is the most common lung tumor in children. Anaplastic lymphoma kinase, a receptor-type protein tyrosine kinase, is present in 50% of these tumors, and this finding may support an imaging diagnosis of IMT. Carcinoid tumors account for a substantial portion of childhood lung tumors, and their characteristic avid enhancement on images corresponds to the compressed fibrovascular stroma histologically. Furthermore, novel imaging agents used with somatostatin receptor analogs have an emerging role in the evaluation of carcinoid tumors. Although less common than mucoepidermoid carcinoma, adenoid cystic carcinoma tends to recur given the perineural spread seen histologically. Integrating radiologic and pathologic knowledge is critical to accurate diagnosis, treatment planning, and surveillance of primary lung tumors in children.

Histologically benign but clinically malignant neoplasms in the thorax: CT-pathological overview

The purpose of this article is to review the computed tomography (CT) and histopathological features of uncommon primary neoplasms of the thorax that can manifest clinically malignant features (multiplicity of pulmonary nodules, an invasive nature, and metastases or recurrence after surgery) with little evidence of histological malignancy.

Lung involvement in juvenile onset recurrent respiratory papillomatosis: a systematic review of the literature

OBJECTIVES

Determine the exact incidence of pulmonary involvement in recurrent respiratory papillomatosis (RRP); explore available treatments and their effectiveness; determine the characteristics of cases that progress to lung cancer.

DATA SOURCES

MEDLINE, EMBASE, and the Cochrane Library databases between 1966 and 2007; reference lists of retrieved publication.

STUDY SELECTION

Studies investigating recurrent respiratory papillomatosis with lung involvement. Age limited to 20 years of age to qualify for the diagnosis of juvenile-onset RRP.

DATA EXTRACTION

Data pertaining to study design, population demographics, risk factors, site of involvement, investigation including the determination of the human papillomavirus type, treatment, and outcomes including the development of cancer.

DATA SYNTHESIS

No randomized control trials were retrieved. Hundred and one studies met our inclusion criteria (23 cohorts, 4 case series, 72 case reports, 2 open trials) with 161 cases of lung involvement identified. From the cohort studies we could estimate the incidence of lung involvement in RRP at 3.3%. The incidence of cancer in cases with lung involvement was 16%. We could not draw conclusions regarding treatment effectiveness in lung involvement, as that was not evaluated except in case studies. It would nevertheless appear that Interferon is not effective and the use of intravenous Cidofovir needs to be better evaluated.

CONCLUSION

Well-designed, hypothesis-driven randomized control trials and prospective cohort studies are warranted to improve our understanding of the mechanisms underlying the development of lung involvement in RRP, the risks associated with different HPV types, the efficacy of potential therapeutic options as well as the risk of progression to cancer.

Recurrent respiratory papillomatosis

Recurrent respiratory papillomatosis is a relatively rare disease caused by members of the human papilloma virus family. Lesions may occur anywhere throughout the respiratory tract but show a predilection for squamo-columnar epithelial junctions, frequently leading to hoarseness and upper airway obstruction. Rarely, it can progress to squamous cell carcinoma. The impact of recurrent respiratory papillomatosis on patients, their families, and the health care system is considerable. Unfortunately, despite extensive investigational studies, no cure is available for the disease. This article reviews the aetiology of and therapeutic options for recurrent respiratory papillomatosis.

Unusual primary lung tumors: a radiologic-pathologic overview

Although the great majority of lung carcinomas are histologically characterized as adenocarcinoma, squamous cell carcinoma, large cell undifferentiated carcinoma, or small cell carcinoma, a variety of rare benign and malignant lung tumors may sporadically affect the lung. Several nonneoplastic tumorlike lesions are seen infrequently but are also part of the differential diagnosis for lung masses. Conventional radiographic findings, although of limited value in the diagnosis of these entities, should be examined carefully when lung tumors are suspected. Computed tomography (CT) is well suited for making a definitive diagnosis of some disease processes. CT helps determine the location and features of the lesions and depicts associated findings to help document the extent of disease. The differential diagnosis can be narrowed when there are typical CT features (eg, the presence of fat in lipoid pneumonia). Although unusual primary lung tumors are difficult to diagnose on the basis of imaging findings alone because such findings are nonspecific in the majority of cases, cross-sectional imaging can play an important role in the diagnostic work-up of these unusual tumors by delineating their extent and directing the radiologist or bronchoscopist to the appropriate biopsy site.