Volume 5, Issue 3 , Pages 124-125, September 2010
Stridor in a newborn caused by infantile myofibromatosis—A case review
Article Outline
Abstract
Infantile myofibromatosis is a common fibrous tumor of infancy, however still considered a rarity. A newborn boy was examined due to inspiratory stridor and subcostal retractions since birth. Several subcutaneous nodules were present on the trunk and legs. Transnasal fiberoptic laryngoscopy and trachea-laryngoscopy showed discrete edema of the anterior part of the vocal cords but no other apparent abnormality. MRI raised suspicion of a laryngeal tumor. Through an external laryngofissure a lesion extending from the right hemilarynx was exposed and excised in fractions. Pathological examination showed infantile myofibromatosis.
Stridor in newborns is frequently caused by congenital laryngeal anomalies, i.e. laryngomalacia but a neoplastic process should be considered as a differential diagnosis.
Keywords: Infantile myofibromatosis, Larynx, Stridor
1. Introduction
The etiology of stridor in infants can be divided into the following subgroups: (1) congenital, (2) inflammatory, (3) neoplasia and (4) iatrogenic. Among the more frequent reported are laryngomalacia, vocal cord paralysis and gastro-esophageal reflux [1], [2]. Neoplasias are usually represented by papillomas and cysts, but occasionally other tumors are encountered giving rise to diagnostic challenges.
Infantile myofibromatosis (IM) is a common benign fibrous tumors found in infants [3]. In spite of this it is considered a rarity among most clinicians. IM is characterized by subcutaneous nodules located on the head, neck and trunk and occurs in three forms: (1) solitary (2) multicentric and (3) generalized [4]. The disease is usually congenital and sporadic though both recessive and dominant inheritance has been described [5]. The disease is considered benign and the prognosis is excellent as the lesions most often involutes spontaneously. The generalized form, however, includes visceral involvement producing significant morbidity and mortality, especially with affection of the cardio-pulmonary system. In the following we describe a case of multicentric IM in a newborn with an unusual location.
2. Case
A boy delivered by acute caesarean section in week 38 due to lack of progression during labor. The birth weight and length was 2850
g and 50cm, respectively. Inspiratory stridor was noted immediately and the condition was aggravated with increasing activity of the child. The boy had subcostal retractions but no cyanosis or hoarseness. His dietary intake was insufficient and he failed to thrive. The stridorous respiration was apparently not depending on the body position. Three subcutaneous nodules and one intramuscular measuring from 0.5 to 3cm in diameter were present on his trunk and left leg. Echocardiography and chest X-ray were normal. Ultrasound showed solid tumors well circumscribed with capsular structure and rich vascularization. Complete blood count, urine-HVMA and VMA were within normal limits. Transnasal fiberoptic laryngoscopy in the out-patient clinic was without visible abnormality in the larynx and upper trachea. Laryngo-tracheo-bronchoscopy and nasal endoscopy in general anesthesia were also without any pathological findings apart from a discrete edema of the anterior part of the vocal cords. MRI demonstrated the above mentioned lesions and no sign of visceral involvement in the abdominal and thoracic regions. However, suspicion of a tumor measuring 5mm in close proximity to the right hemilarynx was raised (Picture 1). Incisional biopsy from the medial aspect of the left knee was undertaken in order to obtain a diagnosis (Picture 2).
Picture 1.
MRI showing a tumor in the right part of the larynx.
Picture 2.
Subcutaneous nodule located on the medial aspect of the left knee.
The histological examination demonstrated a tumor comprised of two cell populations: (1) Fascicles of located peripheral myoid spindle cell components and (2) classic central cellular components of primitive cells with haemangiopericytoma-like blood vessels (Picture 3). Proliferation index was 1–5%. Immunohistochemically, positive reactions for vimentin and smooth muscle actin were found. Negative reactions were observed with regards to desmin, S-100, CD34, CD31, FLI-1, myogenin, neurofilament, CD56, CD99, ALK-1, D2-40, EMA, KL-1, GFAP, betacatinin, bcl-2, and melan-A. There was no evidence of malignancy. The diagnosis was established as infantile myofibromatosis.
Picture 3.
(A) HE ×200: Classic central cellular component. Primitive cells with haemangiopericytoma-like blood vessels. (B) HE ×200: Classic more peripheral myoid spindle cell component.
An external surgical approach through laryngofissure was then performed. The exploration using microscopy showed a tumor situated between the medial part of the right thyroid cartilage and the false vocal cord. The tumor was excised in fractions avoiding tracheotomy. The boy was kept intubated for a week where after extubation was performed without any complications. Pathological examination confirmed the diagnosis infantile myofibromatosis.
The breathing difficulties resolved following the neck surgery and until now show no sign of recurrence. The boy continues treatment at the pediatric oto-rhino-laryngology department and will be followed-up in 1 year with MRI and laryngo-tracheoscopy.
3. Discussion
To our knowledge, only few cases of IM located in the larynx have been described previously [6], [7]. The differential diagnoses of IM are several i.e. neurofibromatosis, lipofibromatosis and the malignant infantile fibrosarcoma and rhabdomyosarcoma. The distinction is made microscopically with the aid of immunohistochemistry as described above. If an infant presents with solitary or multiple subcutaneous nodules IM should always be considered. Most cases have an excellent prognosis with a pronounced spontaneous regression. However, approximately 15–20% are generalized with a very poor survival rate. Evaluation with thorough whole body imaging as well as follow-up is advocated due to a tendency of local recurrence
In the case described the transnasal fiberoptic larynscopy and laryngo-tracheoscopy were without pathology apart from a discrete edema. However, this must have been sufficient to cause airway obstruction in the child especially during increased activity, i.e. crying and breastfeeding, as the symptoms completely resolved following surgery.
Stridor in a newborn is usually due to congenital laryngeal anomalies most often laryngomalacia. Nevertheless, neoplastic processes should be kept in mind as differential diagnose.
References
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- . Fibromatosis and fibrosarcoma of the larynx and pharynx in an infant. Archives Otolaryngol. – Head Neck Surgery. 1985;111:478–480
PII: S1871-4048(09)00039-2
doi:10.1016/j.pedex.2009.07.001
© 2009 Elsevier Ireland Ltd. All rights reserved.
Volume 5, Issue 3 , Pages 124-125, September 2010
