Neuroradiology Case of the Month

January 2002

Manoj Ketkar MD and P-L Westesson, MD, PhD, DDS

Clinical Presentation: A 4-year-old female child with facial deformity was referred for CT scan of head and face.

CT Findings: Focal thickening of the basi-sphenoid, the Greater Wings of sphenoid bone bilaterally, left maxilla, right squamous temporal bone and right occipital bone is noted (Fig. 1). Also noted is the ground glass appearance of the involved bones. There is minimal narrowing of the left optic canal due to thickening of the sphenoid bone.

Additional Imaging Findings: The long bones had multiple mixed lytic and a few sclerotic areas in the femurs, tibia and fibula bilaterally. In some of these lytic areas, expansion of the bone with cortical thinning was noted (Fig. 2).

The pelvic ultrasound revealed increase in the size of the right ovary with a large uterus, consistent with patient’s precocious puberty (Fig. 3).

Diagnosis: McCune-Albright Syndrome.

Figure 1(A & B): Axial non- contrast CT scan of the skull base showing ground glass appearance and thickening of the involved bones and minimal narrowing of the left optic canal (arrow).

A	B
Figure 2 (A& B): Long bones X-rays shows bilateral lytic and sclerotic areas with expansion of the bone characteristic for polyostotic fibrous dyplasia.

A

B

Figure 3 (A & B):Pelvic ultrasound showing enlarged uterus and increase in the size of the right ovary.

Discussion: Severe cases of this syndrome may be recognized shortly after birth. Less severe cases can occur at any time during childhood.

Gonadotropin independent precious puberty is more common in affected girls than boys. Other manifestations occur equally in both sexes. This syndrome affects all races equally [1].

McCune-Albright syndrome has three main components:

1. Precocious Puberty:
Precocious puberty is the most common feature of McCune-Albright syndrome. It is the result of gonadotropin independent autonomous ovarian or testicular function [1]. Hyperthyroidism is a known association, which was seen in our case.

2. Fibrous Dysplasia:
Fibrous dysplasia is polyostotic type, i.e. affecting multiple bones. It usually involves long bone such as femur, tibia, and fibula.

Asymmetric involvement is often seen, as seen in our patient. When skull base and facial bones are affected the clinical presentation can be facial deformity and cranial nerve palsies [2].

3. Café au Lait spots:
Café au Lait spots in McCune-Albright syndrome are large melanotic macule. Except for hyperpigmentation of the basal layer, no abnormal pathology is seen [1].

References:

1. Boston BA. eMedicine Journal, May 13, 2002, Volume 3, Number 5.
2. Osborn A. Diagnostic Neuroradiology. 1994: 509-510, Mosby - Year Book Inc., St. Louis, Missouri.