Mysterious lumps

Paediatric dermatology

Dr. Emmanuelle Bourrat

Saint-Louis Hospital

The clinical case
Now it's your turn!
Co-prescription and advice

Clinical case presentation

A newborn female had had large cranial swellings in the frontal and occipital regions since the age of 10 days. These swellings were fluctuating.
The vaginal delivery did not require any instrumental maneuvers. She did not seem to be in any pain during flare-ups, spontaneously, or on palpation.

The swellings could reach several centimeters in diameter, were firm, fixed to the deep plane, covered by skin of normal color and temperature, non-pulsatile, and without bruit.

Several radiologic investigations were performed during a flare-up: ultrasound showed a vascularized subcutaneous mass and CT confirmed a 4 cm occipital soft-tissue swelling sparing the bony calvaria. MRI with low T1 signal, high T2 signal and strong post-gadolinium enhancement was suggestive of a deep hemangioma, but because the consistency and fluctuating course were not typical of an infantile hemangioma, an ultrasound-guided biopsy was then performed.

Your turn

What is your diagnosis?

Select 1 answer(s) from the following choices:

Myofibromatosis

Infantile hemangioma

Chloromas

Meningocele

Wrong answer!

Good answer!

Diagnosis selected

The histological appearance of benign myofibroblast proliferation allows a diagnosis of multifocal subcutaneous infantile myofibromatosis of the scalp. Radiological examination ruled out any visceral involvement and the condition slowly regressed spontaneously over several months, except for a calcified occipital area that persisted in the form of a fixed nodule.

Infantile myofibromatosis is a fibrovascular proliferation that most often occurs in the skin but can also be subcutaneous, osseous or visceral. Lesions are sometimes congenital, often appearing early (before age 2), but sometimes later. They may be solitary or multiple, sporadic or familial (and in this case related to germline PDGFRB mutations). Spontaneous prognosis is favorable except in visceral forms, which are often multifocal and aggressive.

Myofibroma should therefore be systematically considered in all cases of tumors in young children and confirmed by histology.

Explanation of incorrect answers

Infantile intramuscular hemangioma was one of the radiologists’ hypotheses, but the fluctuating nature of the lesion was highly atypical.
Chloroma is an extramedullary deposit of myeloid blasts, commonly found in the skin and frequently affecting the cranial vault. It occurs in the context of acute myeloid leukemia, which was not the case in this patient.
Cranial meningocele is a rare malformation of the central nervous system characterized by herniation of the meninges due to a permanent defect in the ossification of the calvaria. It contains cerebrospinal fluid but no brain tissue. Here, it was excluded by imaging.

Treatment

In its solitary cutaneous form, infantile myofibroma is often spontaneously reversible and does not require treatment in the absence of significant impact, as was the case in this patient.

Expert's message

The clinical and radiologic appearance of infantile myofibroma is sometimes pseudo-inflammatory, as in this case, and should not mislead the diagnosis toward a malignant tumor or vascular malformation.

References:

^{N. Delorme, M.-X. Doré, A. Croué, H. Maillard, J.-L. Verre.}^{Unusual presentation of plaque-type ulcerated infantile cutaneous myofibromatosis.}^{Ann Dermatol Venereol}^{2005;132:338–341.}