Sclerosing hemangioma, presenting as a pneumonic pattern with mucinous adenomatous hyperplasia of the lung

Benign tumours of the bronchopulmonary system

The vast majority of tumours arising in the bronchopulmonary system are malignant in nature. Benign tumours of the lung are relatively rare and are often incidental findings during clinical investigations for unrelated conditions. These lesions can arise in the bronchial tree or the pulmonary parenchyma and may be of epithelial, mesenchymal, salivary gland-type or unknown differentiation. Although the spectrum of these lesions is wide, the clinical, pathological and immunohistochemical characteristics of the most relevant will be the subject of this review. In addition, the most important features allowing differentiation from malignant pulmonary neoplasms will be discussed.

Ciliated Muconodular Papillary Tumors of the Lung

Ciliated muconodular papillary tumor is a rare tumor of the lung with 38 cases reported to date in the English literature. It is typically found incidentally in older adults (average age, 67 years) as a small, peripheral, ground glass opacity or nodule on computed tomography. Microscopically, the tumor is composed of a mixture of ciliated columnar, mucous, and basal cells in a variety of architectural patterns including glandular, papillary, lepidic, and micropapillary growth patterns. Recently, studies have shown the tumor has several associated gene alterations, supporting that the lesion is indeed neoplastic. The tumor seemingly follows an indolent clinical course, as there have been no reported recurrences or metastases. In this article, we review the clinical, radiographic, pathologic, and molecular findings of ciliated muconodular papillary tumors. Diagnostic pitfalls and the diagnostic considerations are discussed.

Ciliated muconodular papillary tumor of the lung: A report of five cases

Ciliated muconodular papillary tumor (CMPT) of the lung is a newly defined and extremely rare tumor characterized by a papillary growth pattern, consisting of ciliated columnar cells, mucous cells, and basal cells with abundant mucin production. Tumor definitions and clinicopathological features continue to be debated. Herein, we report five surgical cases of CMPT to characterize its radiographic, gross, and microscopic features. The five cases involved three male patients aged 80, 67, and 66 years, and two female patients aged 73 and 70 years. Three cases were discovered during health care screenings, and two cases were found during follow-up for another synchronous cancer. Histopathological examination revealed that the tumor tissue was composed of ciliated columnar cells, mucous cells, and basal cells with abundant mucin production. Neither nuclear atypia nor mitotic figures were observed. All patients had good prognoses. The benign histological features and clinical courses in these five cases suggest that CMPT is an independent and benign tumor of the lung.

Ciliated muconodular papillary tumors of the lung: a clinicopathologic analysis of 10 cases

Ciliated muconodular papillary tumors (CMPTs) are rare peripheral nodules of the lung first described in 2002. Because of their rarity and nonstandardized diagnostic terminology, CMPTs have been poorly recognized among pathologists. To better characterize these lesions, we undertook a detailed clinicopathologic and immunohistochemical study of 10 archival cases. Ten CMPTs occurred in 7 men and 3 women with a median age of 62 years. All were small peripheral nonendobronchial nodules with a mean diameter of 1.0 cm. All but 1 tumor were incidentally detected by computed tomography-based screening, all of which were radiologically interpreted as adenocarcinomas. Although limited surgery treated all but 1 CMPT, they followed a benign course with no recurrence at a mean follow-up of 43 months (range: 2 to 88 mo). Histologically, CMPTs showed glandular and/or papillary architecture, comprising a vaguely organized mixture of nonatypical ciliated columnar cells, mucous cells, and basal cells, often enveloped by copious intra-alveolar mucin. Micropapillary tufts of ciliated cells and seemingly discontinuous growth along alveolar walls were occasionally present, mimicking adenocarcinomas. Ciliated cells and basal cells were immunopositive for TTF-1 and p40, respectively, whereas mucous cells lacked HNF4α expression. CMPTs are rare, likely benign, underrecognized processes of the lung that should be distinguished from adenocarcinomas.

Cytologic features of sclerosing hemangioma of the lung on crush preparations

Sclerosing hemangioma of the lung is a rare benign neoplasm. The majority of the literature published on sclerosing hemangioma has focused on the histologic features, while only a few case reports have described the cytologic features. We report two additional cases of sclerosing hemangioma of the lung in which the cytologic material was prepared at the time of frozen section. Because of the rarity of this lesion and the overlapping cytologic features with other primary malignant lung tumors, awareness of the cytologic features of sclerosing hemangioma may help to avoid a diagnosis of malignancy. This is especially true pre- and intraoperatively because a limited resection may suffice if a diagnosis of sclerosing hemangioma can be established.