An Unusual Bruise on the Face of a 20-month-old Boy

MayFlower is a 20-month-old boy with a >1 month history of an unusual bruise that arose after he bumped his face against his toy chest 4-5 weeks ago. He is otherwise totally well.

On the young boy's face there is a very firm reddish-blue nodule that feels like there are several lumps within it.

Past medical history is non-contributory. Physical examination: There is A 2.5-cm firm reddish-blue nodular lesion on his left upper cheek. There is no hepatosplenomegaly. He is without any other skin lesions. The only test ordered is a CBC which reveals a normal differential and normal indices.

A close-up view...A very firm reddish-blue nodule that feels like there are several lumps within it. There is a “tent” appearance when skin is stretched.

Time to figure a differential diagnosis. We have a well child with a lump/bump after well documented accidental trauma. As bad as this appears, there is nothing to make us think this is a malignant lesion.So, do you have a differential diagnosis for lumps and bumps in childhood? Which lump is the most common?

Here is my differential diagnosis: Fibroma, neurofibroma, lipoma, lymphangioma, juvenile xanthogranuloma, granuloma annulare, mastocytomas, malignant tumor (usually sarcomas), epithelial inclusion cyst, pilomatrixoma, miscellaneous.

What is your differential diagnosis of a reddish-purple lump on a young child's face after known trauma?

Answer: Pilomatrixoma (calcifying epithelioma of Malherbe). Second most common superficial lump in children after epidermal inclusion cysts. Is an acquired hamartoma of hair follicle origin (ie, a nonmalignant mutation of hair matrix cells). Hard, multilobular papule or nodule with a bluish color. Stretching of skin over lesion can give a “tent” appearance.

Treatment: surgical excision is best for pilomatrixoma. Histology of pilomatrixoma reveals sheets of compact basal cells alternating with “ghost” or “shadow” cells. There is often calcification.

Differential diagnosis in order of occurrence: Epithelial inclusion cyst - 59%, pilomatrixoma - 10%, miscellaneous - 9%, fibroma - 4%, neurofibroma - 3%, lipoma - 3%, lymphangioma - 3%, juvenile xanthogranuloma - 3%, granuloma annulare - 3%, mastocytomas - 2%, malignant tumor (usually sarcomas) - 1%.

This one is not a good story: this is a 3-year-old with the rapid onset and growth of a very hard nodular lesion that was violacious. A biopsy confirmed our worst fears… a lymphosarcoma.

And that is the end of this tale…MayFlower had a successful surgical removal and lived happily ever after… as far as I know.