Hamartoma
Overview
A hamartoma is a benign growth composed of an abnormal mixture of cells and tissues that are normally found in the area of the body where the hamartoma occurs.
Unlike other types of tumor, which grow uncontrollably, hamartomas are generally well-differentiated and grow at the same rate as the surrounding tissues.
Key characteristics
- Disorganized growth
- Benign nature
Most hamartomas are found incidentally and do not require treatment unless they cause symptoms or complications.
Key example
| Type | Location | Contents | Key Clinical Points |
|---|---|---|---|
| Pulmonary Hamartoma | Lung | Cartilage, fat, connective tissue | Most common benign lung tumor; “popcorn” calcification; often incidental. |
| Hypothalamic Hamartoma | Hypothalamus | Neuronal and glial tissue | Causes gelastic seizures, precocious puberty; may need surgery/radiotherapy. |
| Renal Harmartoma (Angiomyolipoma) | Kidney | Vessels, muscle, fat | ↑ Bleeding risk if large; associated with Tuberous sclerosis. |
| GI Hamartoma (Peutz-Jegher) | GI tract (small bowel) | Mucosal and stromal elements | Polyps → obstruction, bleeding; ↑ risk of GI & extra-GI malignancies. |
| Breast Hamartoma (Fibroadenolipoma) | Breast | Glandular, fibrous, fatty tissue | “Breast within a breast” on mammo; benign; may cause cosmetic concerns. |
| Cardiac Rhabdomyoma | Heart (esp. infants) | Cardiac muscle cells | Linked to Tuberous sclerosis; may regress; can cause arrhythmias/obstruction. |
