Alveolar adenoma of the lung

Abstract

Alveolar adenoma is a rare and benign tumour of the lung that usually presents in asymptomatic patients as a coin lesion on chest radiography. Only 25 cases have been reported in the English medical literature. Alveolar adenoma has a characteristic multicystic histology and often resembles the normal lung parenchyma. Ultrastructural studies indicate that the epithelial cells lining the cysts are type-II pneumocytes. Immunohistochemical analysis may aid in the characterization of alveolar adenoma and discriminate this condition from other types of benign lesions of the lung. An indolent clinical progression and absence of recurrence and metastasis after complete resection are the most important characteristics indicative of the benign nature of alveolar adenoma. Few studies have been conducted at the molecular level, such as by flow cytometry, with the objective of characterizing the biological nature of alveolar adenoma. Differential diagnoses include sclerosing hemangioma, papillary adenoma, lymphangioma, atypical adenomatous hyperplasia and bronchioloalveolar carcinoma. In this article we describe the immunohistochemical and flow cytometric features of this neoplasm in two male patients. Both the tumours showed a diploid DNA pattern with a low proliferation index. p53 test was found to be negative, and post-operative follow-up examinations at 22 and 32 months proved uneventful.

Alveolar adenoma of the lung: unusual diagnosis of a lesion positive on PET scan. A case report

“…Although the exact number of case is unknown since these neoplasm have been confused with similar benign lesion, there are few cases reported. Only 29 cases were descibed in English medical literature [2,4,5] and almost all of them are peripheral and subpleural coin lesion, like a solitary pulmonary nodule. One reported case was localized near lung hilum 3 and another one was a multiseptated huge cystic mass 5 .…”

An unusual case of a microscopic alveolar adenoma coexisting with lung carcinoma: a case report and review of the literature

“…AAs are characterized by proliferation of type II alveolar epithelium and septal mesenchyma [3]. They are histologically benign, and recurrence after resection has never been reported [4-6]. AAs are detected incidentally as isolated coin lesions on routine chest radiographs [4,7]; however, at times, they are difficult to differentiate from the early stages of lung cancer.…”

“…They are well demarcated peripheral pulmonary lesions composed of a network of spaces lined with simple cuboidal epithelium that contain stroma ranging from thin, inconspicuous strands of connective tissue to broad accumulations of spindle cells accompanied by a myxoid matrix [4]. A review of the English language medical literature revealed that fewer than 30 cases of AA have been reported to date [1,4-6]. We describe the rare case of an incidental, microscopic (0.2 cm) AA coexisting with lung carcinoma.…”

Multicystic Alveolar Adenoma in a Symptomatic Adult with Extensive Bullae and Mediastinal Shift

“…Since then, alveolar adenomas are still rarely reported in the literature with approximately only 40 cases reported [2]. The most common presentation is of an asymptomatic solitary, peripheral lesion that is incidentally discovered on chest imaging [2][3][4][5][6]. Alveolar adenomas rarely present as a solitary cystic lesion [4,[6][7][8].…”