What is the clinical significance of a hamartoma (benign tumor)?

From the Guidelines

Hamartomas are generally benign and asymptomatic, requiring no treatment, but their clinical significance varies depending on location and size, and they may cause problems when they compress surrounding structures or interfere with normal organ function. The management of hamartomas typically involves observation for asymptomatic lesions, while symptomatic hamartomas may require surgical removal 1. Imaging studies like CT, MRI, or ultrasound are used for diagnosis and monitoring, and can help distinguish hamartomas from true neoplasms, which is important for proper patient management 1.

Some key characteristics of biliary hamartomas, also known as Von Meyenburg complexes, include:

• They are typically small, ranging in size from 2 to 10 mm
• They may be hypoechoic, hyperechoic, or mixed heterogenic echoic structures on ultrasound
• They appear as multiple hypoattenuating lesions on CT, predominantly in the subcapsular and periportal areas
• They are hypointense on T1-weighted MRI sequences and show markedly high intensity on T2-weighted sequences
• They often possess an irregular shape with well-defined margins, and may display a "starry sky" appearance on MRI 1.

While the risk of malignant transformation of biliary hamartomas is considered low, with only a few reported cases, it is still important to distinguish them from true neoplasms and to monitor patients with hamartoma syndromes, such as Cowden syndrome or Peutz-Jeghers syndrome, due to their association with increased cancer risk 1. Regular follow-up is recommended for patients with hamartoma syndromes, and asymptomatic patients with biliary hamartomas and concomitant liver diseases should have a follow-up that is determined by the primary liver disease.

In terms of treatment, endoscopic resection is generally recommended for duodenal adenomas (DAs) and other symptomatic or large hamartomas, while non-neoplastic lesions, such as metaplastic foveolar epithelium, gastric heterotopia, and inflammatory/pseudopolyps, do not require removal unless they are symptomatic or large 1. Overall, the clinical significance of hamartomas depends on their location, size, and symptoms, and management should be individualized based on these factors.

From the Research

Clinical Significance of Hamartomas

The clinical significance of a hamartoma, a benign tumor, can be understood through various studies that have examined its characteristics and effects on the body.

• Hamartomas are composed of aberrant disorganized growth of mature tissues, and can be found in various parts of the body, including the lungs, skin, and soft tissue 2, 3.
• In the lungs, hamartomas are the most common benign tumors and are usually slow-growing, often found incidentally on chest imaging during the sixth decade of life 4, 5, 6.
• While hamartomas are generally asymptomatic, they can cause a range of symptoms depending on their size and location, including chronic cough, dyspnea, chest pain, and weight loss 4, 5, 6.
• In some cases, hamartomas can cause airway obstruction and recurrent post-obstructive pneumonia, highlighting the need for proper diagnosis and treatment 4, 5.

Diagnosis and Treatment

• The diagnosis of hamartomas can be challenging, and may require a combination of imaging studies, such as computed tomography (CT) scans, and histopathological examination 5, 6.
• Treatment options for hamartomas vary depending on their location and size, but may include surgical resection, such as sleeve resection lobectomy 5.
• It is essential to thoroughly investigate hamartomas to ensure appropriate patient management, as they can be associated with other conditions, including extrapulmonary cancer diagnosis 6.

Imaging and Syndromes

• Hamartomas can be found in virtually any organ system, and their imaging appearance varies depending on the organ they arise from 3.
• Radiologists play a crucial role in diagnosing hamartomas, and must be aware of the clinical and imaging presentations of these lesions to avoid unnecessary studies or invasive procedures 3.
• Knowledge of common syndromic entities, such as tuberous sclerosis or Carney triad, is also essential, as hamartomas can be a part of these syndromes 3.