Age / Sex : 6 / F

Age / Sex : 6/F

Chief complaint : Anemia and Jaundice

1) What is your impression?

Two weeks later, you can see the final diagnosis with a brief discussion of this case.

* Send Application Answers to In Sook Lee, MD (lis@pusan.ac.kr)

Courtesy : Yeo Ju Kim , Inha University Hospital

Cranial vault thickening due to bone marrow hyperplasia in hemolytic anemia

Discussion

Findings:

1)      On anteroposterior and lateral skull radiographs, and CT scan of skull show widening of the diploic space with thining of outer table in frontal and parietal bones.

2)      On ultrasonography of abdomen, GB stone is noted.

Differential Diagnosis:

 The differential diagnoses for calvarial thickening

1)      Diseases which result in bone marrow expansion such as hemolytic anemia, chronic iron deficiency anemia, uncorrected cyanotic congenital heart disease

2)      Dilantin toxicity

3)      Hypoparathyroidism, Peudohypoparathyroidism

4)      Healing rickets

5)      Paget's disease

6)      Fibrous dysplasia

Diagnosis: 

Cranial vault thickening due to bone marrow hyperplasia in hemolytic anemia

Discussion:

 Radiologic finding of skull change in patients with hemolytic anemia are produced by red marrow hyperplasia and circulatory factor. Red marrow hyperplasia causes widening of the diploic space, and the outer table thins or is completely obliterated. Coarse granular or stippled pattern due to red marrow hyperplasia can be seen in upper parietal region before diploic widening. When the hyperplastic marrow perforates or destroys the outer table, it proliferates under the invisible periosteum, and new bone spicules are laid down perpendicular to the inner table showing “hair-on-end” sign. Circulatory factor such as stasis and small vessel occlusion result in patchy or diffuse opacity with granual cranial vault widening.

In a normal person with thick skull all component layers contribute to overall thickness. Presence of diploic layer more than 2.5 times the combined thickness of inner and outer tables suggests diseased state. Diploic thickening is significant in frontal and parietal region and does not involve squamous portion of temporal or occipital bone. Diploic thickening is nonspecific and can be seen in any condition that produces marrow hyperplasia such as iron deficiency anemia, sickle cell disease, spherocytosis, and thalassemia major.

References:

1)      Sebes JI, Diggs LW. Radiographic changes of the skull in sickle cell anemia.AJR Am J Roentgenol. 1979 Mar;132(3):373-7.

2)      Hollar MA The hair-on-end sign Radiology. 2001 Nov;221(2):347-8.