Precocious puberty presents a unique diagnostic challenge, characterized by the early onset of pubertal changes, such as menarche or the development of secondary sexual characteristics, before the age of 9 years in boys and 8 years in girls. This condition necessitates prompt evaluation, not only to alleviate the concerns of anxious parents but also to initiate appropriate treatment without delay. Accurate and timely diagnosis is essential to ensure optimal outcomes, and imaging plays a pivotal role in distinguishing between central and peripheral causes, thereby impacting therapeutic strategies.

Fig 1: Imaging Armamentarium in Precocious Puberty

CPP is always isosexual whereas PPP can be iso or hetero-sexual.

Table 1: Difference between Central and Peripheral Precocious Puberty

Recognizing and employing the appropriate imaging modalities is fundamental to achieving a reliable diagnosis.

A radiograph of the left hand and the wrist is usually the first imaging modality for evaluating bone age. This simple yet effective tool provides insight into the progression of puberty relative to chronological age.

Ultrasound is done for evaluating the uterus and ovaries in girls and the testes in boys. It aids in identifying peripheral causes, such as ovarian cysts or tumors, that may contribute to early hormonal activity.

In females with peripheral precocious puberty (PPP), the most common cause is an autonomously functioning ovarian cyst. These cysts produce hormones independent of gonadotropin stimulation, leading to signs of precocious puberty. In all patients with precocious puberty the adrenals must be evaluated to rule out an underlying cause. In cases of PPP, unilateral gonadal enlargement warrants careful evaluation for an underlying pathology. This could include conditions such as hormone-secreting ovarian tumors, adrenal tumors, or other localized abnormalities contributing to excessive hormone production.

Table 2: Heterosexual vs Isosexual Peripheral precocious puberty

In both boys and girls, magnetic resonance imaging (MRI) is considered the gold standard for central nervous system evaluation. MRI is essential for detecting central causes such as hypothalamic hamartomas, tumors, or other structural abnormalities that may trigger early activation of the hypothalamic-pituitary-gonadal axis.

Fig 3: Appearance of normal pituitary in a child and at puberty

CPP : females < 6 years usually have an underlying pathology and must be evaluated with a MRI. All boys with CPP must be investigated with a MRI as there is always an underlying cause.

Fig 4: MRI Brain reporting checklist