1. MedPix Medical Image Database COW - Case of the Week Case Contributor: Jennifer Gerlach Affiliation: No Academic Affiliation

2. MedPix No: 7723 - History Pt Demographics: Age = 9 y.o. Gender = boy 9 year old white male with precocious puberty. Downloaded by (-1)

3. MedPix No: 7723 - EXAM & LABS This is a 9 year old white male who presented at 8 years old to a new pediatrician for his well child check. At this time no abnormalities in growth or development were noted. He was a Tanner stage 1. One year later he returned for his 9 year old well child checkup. The physician noted that he had facial acne, a long jaw, and adult-like muscle definition and veins. He was noted to be at a Tanner stage 3. The patients mother denied any *laughing spells* or seizures. Laboratory data showed a testosterone level of 400 (>300 is an adult level). His cortisol was within normal limits. A bone age was determined via x-ray and showed that he was at greater than 2 S.D. above the mean for his chronological age of 110 months.

4. Hypothalamic hamartoma Tiny mass in region of sella is separate from pituitary, optic chiasm and stalk. Downloaded by (-1)

5. Hypothalamic hamartoma Tiny mass in region of sella is separate from pituitary, optic chiasm and stalk. Downloaded by (-1)

6. Hypothalamic hamartoma Tiny mass in region of sella is separate from pituitary, optic chiasm and stalk. Downloaded by (-1)

7. Hypothalamic hamartoma Tiny mass in region of sella is separate from pituitary, optic chiasm and stalk. Downloaded by (-1)

8. FINDINGS Impression:- The pituitary gland is positioned within the sella turcica and demonstrates normal signal characteristics.- The infundibulum is not thickened and enhances normally.- A rounded 5mm soft tissue thickening is present along the tuber cinereum midway between the mamillary bodies and the infundibulum. This is isointense to brain tissue on all sequences and does not enhance with IV contrast.- The ventricles are normal in size and configuration. No abnormal signal intensity within the hypothalamus is identified.

9. DIFFERENTIAL DIAGNOSIS What is your Differential Diagnosis? 1. Hypothalamic hamartoma - 2. Craniopharyngioma - 3. Hypothalamic glioma - 4. Ganglioglioma - -

10. Diagnosis: Hypothalamic Hamartoma Dx Confirmed by: The classic clinical presentation of isosexual precocious puberty, along with MRI features of an isointense non-enhancing mass of the grey matter in the region of the hypothalamus is highly suggestive of a hypothalamic hamartoma. In addition #2-4 in the differential all enhance after contrast. The literature supports making the diagnosis based on imaging and clinical history without a pathologic diagnosis.

11. DISCUSSION This child does not have gelastic ssizures. Some authors have been successful using a long acting analog of LRH to control precocious puberty.