Hamartoma of the lung

Malignant Degeneration of Biopsy-Proven Hamartoma to Chondrosarcoma

Pulmonary hamartomas are benign lesions that are often managed conservatively in the absence of respiratory symptoms. Increasing reports of malignant transformation question if a more aggressive treatment or surveillance practice for these lesions is warranted in adult patients. Herein, we describe a case of a 67-year-old man with a long history of pulmonary hamartoma that demonstrated malignant degeneration into spindle cell malignancy with chondromatous differentiation. This case illustrates the aggressive nature of sarcomatous disease arising from hamartomas and, with a handful of other cases in the literature, points to the question of whether pulmonary hamartomas arising in late adulthood should follow a more intensive treatment or surveillance algorithm given increased concern for malignant potential.

Solitary pulmonary nodule: A diagnostic algorithm in the light of current imaging technique

The solitary pulmonary nodule (SPN) is frequently seen on chest radiographs and computed tomography (CT). The finding of a SPN usually provokes a flurry of clinical and imaging activity as an SPN in at-risk population is an alert signal of possible lung cancer. The frequency of malignant nodules in a given population is variable and depends on the endemicity of granulomatous disease. The percentage of malignant nodules also rises when dealing with at-risk population. The problem is compounded by the fact that with the present generation of CT scanners, 1-2 mm nodules are discovered in approximately half of the smokers aged 50 years or older scanned. A variety of management approaches are applied in the work-up of SPN often requiring evaluation over a long period of time to establish a benign or malignant diagnosis. Comparison with previous imaging studies and morphologic evaluation of the size, margins, and internal characteristics are usually the first step in the evaluation of these nodules. It is often necessary to use additional imaging techniques and occasionally invasive procedures such a percutaneous needle lung or a surgical biopsy. Until recently, the guidelines for follow-up of indeterminate noncalcified nodules detected on nonscreening CT was a minimum of 2 years. However, during the past few years due to further refinements in CT technology and better understanding of tumor behavior, it has prompted a revision of the guidelines of the follow-up of small indeterminate nodules. These guidelines have been endorsed by the Fleischner Society.

The calcified lung nodule: What does it mean?

The aim of this review is to present a pictorial essay emphasizing the various patterns of calcification in pulmonary nodules (PN) to aid diagnosis and to discuss the differential diagnosis and the pathogenesis where it is known. The imaging evaluation of PN is based on clinical history, size, distribution and the gross appearance of the nodule as well as feasibility of obtaining a tissue diagnosis. Imaging is instrumental in the management of PN and one should strive not only to identify small malignant tumors with high survival rates but to spare patients with benign PN from undergoing unnecessary surgery. The review emphasizes how to achieve these goals. One of the most reliable imaging features of a benign lesion is a benign pattern of calcification and periodic follow-up with computed tomography showing no growth for 2 years. Calcification in PN is generally considered as a pointer toward a possible benign disease. However, as we show here, calcification in PN as a criterion to determine benign nature is fallacious and can be misleading. The differential considerations of a calcified lesion include calcified granuloma, hamartoma, carcinoid, osteosarcoma, chondrosarcoma and lung metastases or a primary bronchogenic carcinoma among others. We describe and illustrate different patterns of calcification as seen in PN on imaging.