Infantile Hypothalamic Hamartoma: A Rare Presentation of Isolated Obesity

Abstract

Hypothalamic hamartomas (HHs) are rare, benign brain tumors or lesions of the hypothalamus that are predominantly identified in cases of epilepsy and central precocious puberty (CPP), whereas isolated manifestations of infantile obesity are atypical. We herein report an 8-month-old boy with severe obesity (Kaup index 26.4 [>100th percentile]) and uncontrollable hyperphagia. His growth chart demonstrated remarkable weight gain that exceeded the length gain in magnitude. Brain magnetic resonance imaging identified a lesion consistent with HH. There were no episodes or clinical findings of epilepsy, CPP, or Cushing disease. Hypothalamic obesity should be considered in the diagnosis even in infants with excessive weight gain due to overeating.

Keywords: hypothalamic hamartoma; hypothalamic obesity; infant; overeating; weight gain.

Figure 1.

Growth chart and calorie intake of the patient. There was remarkable weight gain and little increase in growth rate from age 1 month. The red line before and after hospitalization indicates the recommended calorie intake by the World Health Organization guideline and the caloric goals of treatment, respectively.

Figure 2.

Photograph of the patient. No central obesity, hirsutism, hyperpigmentation, acne, or striae were observed.

Figure 3.

Magnetic resonance imaging of hypothalamic hamartoma (HH) of the patient (A, T1-weighted sagittal image; B, T2-weighted sagittal image; C, T1-weighted sagittal images with contrast agent). A mass lesion approximately 20 mm in size is shown in the suprasellar area. It was isointense compared to the gray matter on T1-weighted imaging (WI) and of slightly higher intensity than the gray matter on T2-WI. No contrast was used.