Damian Gimpel Waikato Cardiothoracic Unit Benign lung tumours Damian Gimpel Waikato Cardiothoracic Unit

Arises from 1950’s  Liebow Classification Essence of classification is origin of growth If any pulmonary nodule can’t be proven to be benign  removed

Classification

Hamartomas Most common benign tumour Roughly 8% of pulmonary neoplasms Asymptomatic Incidentalomas post routine CXR Male 2:1 30-60 years old Location – Peripheral (Note – Can be bronchial)

Hamartomas Mostly solitary pulmonary nodules  rarely multiple nodules well-circumscribed lesions - 1 and 2 cm in diameter Calcification may be present but may not be obvious on the plain chest radiograph. CT  calcification and fat  popcorn calcification in a well demarcated lesion is highly suggestive of a benign neoplasm.

Hamartomas

Clear cell tumour Histology  resemble metastatic renal cell carcinoma Characterized by sheets and cords of polygonal cells separated by a prominent brovascular stroma. Eosinophilic cytoplasm The nuclei are characteristically bland and vary in size; mitoses are usually absent. Peripherally located, and are typically 2 cm or less in size. Immunohistochemical analysis  definitive diagnosis

Germ cell tumour Benign teratomas  rare They occur generally in young patients May occasionally manifest with trichoptysis (coughing out hair)

Germ cell tumour

Epitheloid - AAH Atypical adenomatous hyperplasia (AAH) Also known as  alveolar cell hyperplasia, atypical alveolar hyperplasia, or bronchioloalveolar cell adenoma One or more small, asymptomatic ground-glass opacities in the periphery of the lung. Lesion is often seen adjacent to or within the same mass of a bronchoalveolar carcinoma (BAC). Histologically  proliferation of minimally atypical cuboidal type II pneumocytes.

Epitheloid - AAH Clinical differentiation between AAH and true BAC is essentially impossible

Mesodermal ORIGINS

Sclerosing haemangioma middle-aged women Again asymptomatic  Peripheral well-circumscribed nodule that may be partially calcifi ed Grossly, the lesion may appear hemorrhagic. tumors range in diameter from 1 to 8 cm. Radiographically  well-defined, homogeneous, Round or oval masses in all patients. Histology  four major patterns in the same tumor: solid, papillary, vascular and sclerotic

Sclerosing haemangioma Newer immunohistochemical research  primitive respiratory epithelial cell, not a mesenchymal cell. Reclassification  alveolar pneumocytoma

hemagiopericytoma Wide range of age presentation 2 to 15 cm in diameter. hemoptysis, dyspnea, and chest pain. characterized by its vascularity and the peritheliomatous arrangement of the tumor cells. There are well preserved vascular channels Questionable as to whether this is a true or malignant lesion

Granular cell / Schwannoma solitary pulmonary nodules may occur in the trachea or main stem bronchi, occasionally as multiple lesions. M:F = 1 30-40 years of age younger than that typically of patients with endobronchial malignancies. Patients usually present with cough or other symptoms suggestive of bronchial obstruction

Bronchopulmonary fibroma Tracheobronchial tree or within the pulmonary parenchyma. Fibromas occurring in the pulmonary parenchyma usually are asymptomatic and appear as well-circumscribed nodules without specific characteristics to differentiate them from other lesions. Wedge excision is both diagnostic and curative Histology  abundance of collagen and bland spindle cells

lipoma Bronchial in origin  submucosal fat that is present between cartilaginous rings. Parenchymal lipomas are rare. The symptoms and signs  Location Most common  manifestations of obstruction predominate with the larger lesions. Usually pedunculated tumors with a narrow stalk that are covered by normal respiratory mucosa. Can also arise in the visceral and parietal pleura (RARE)

leiomyoma Rare  Most common soft tissue tumor of the lung. Smooth muscle fibers. Women account for two thirds of the affected patients  AGE 35 solitary, peripheral, pulmonary nodules  Asymptomatic. no specific characteristics that distinguish this lesion from other pulmonary nodules.

Other TYPES

Bronchial associated lymphoid tumours (BALT) Histology  small lymphoid cells interspersed among clusters of plasma cells The tumor usually has a nodular appearance because of its tendency to localize around lymphoid follicles. Post removal  Lymphoma workup If no other evidence of lymphoma exists  out patient follow

Other pulmonary meningioma ganglionoma lymphangioma

diagnosis Incidentalomas: Most benign tumors manifest as asymptomatic nodules found on a routine chest radiography or CT performed for other Reasons. Most are peripheral Small percentage of benign lesions are in an endobronchial location and may be manifested by lobar or whole lung collapse, hyperinflation secondary to a ball-valve mechanism, cough, pneumonia, or, occasionally, hemoptysis.

bronchoscopy when there is an endobronchial lesion diagnosis bronchoscopy when there is an endobronchial lesion However! Most are Peripheral NEED TISSUE!

no criteria are absolute diagnosis no criteria are absolute a number of factors point to a benign diagnosis.

diagnosis Lesions in non smokers, younger than 30 years of age are extremely unlikely to be Malignant Timing  if it has not changed in size over 2 years or longer, it is also generally safe to consider it benign, Dense or central calcification is considered to be a reliable indicator that a lesion is benign, as is popcorn calcification, which suggests a hamartoma.

diagnosis Positron emission tomography  there is clearly significant overlap between the two groups A specific benign diagnosis is made only 10% of the time by bronchoscopy 67% of the time by TTNB.

diagnosis only a definitive benign diagnosis by cytology or microbiologic examination Specific benign findings include cartilage or fat suggestive of a hamartoma or fungal elements or acid-fast organisms diagnostic of an infectious process.

management Simple excision of a benign lesion is curative. Excision may be done without the need for an anatomic resection, although the type of resection is obviously dependent on the location of the lesion. Conservation of lung tissue is paramount.

management Surgical therapy of benign lesions located in the parenchyma is mandated largely by the fact that the diagnosis usually cannot be definitively established until the lesion isremoved.