martedì 27 maggio 2008
Bilateral parotid hemangiomas
Figure 1 and Figure 2: Contrast enhanced axial CT images demonstrate bilateral, lobulated, enhancing masses in the expected region of the parotid glands. No cystic areas are seen within the masses. No normal parotid tissue is seen. Prominent enhancing vessels can be seen adjacent to these masses.
Diagnosis: Bilateral parotid hemangiomas
Hemangioma is not only the most common tumor of the parotid glands in childhood, it is also the most common tumor of infancy. The incidence of hemangioma in neonates is 1-2%. 90% of salivary gland hemangiomas occur in the parotid gland, with the remaining 10% occurring in the submandibular gland. 60% of infantile hemangiomas occur in the head and neck, and can involve virtually any space. They can be seen in association with PHACES syndrome.
On noncontrast CT imaging, parotid hemangiomas appear as lobulated, intermediate density masses without calcifications. During the proliferative phase, parotid hemangiomas typically enhance diffusely, with prominent vessels in and adjacent to the mass. As they spontaneously involute, they decrease in size and undergo fatty replacement.
The differential for these lesions includes venous and arteriovenous malformations (typically contain phleboliths), plexiform neurofibroma (look for other stigmata of neurofibromatosis), and sarcoma (tends to occur in older children and are more likely to be invasive and destructive).
In one study of 100 children with parotid hemangiomas, the female-to-male ratio was 4.5:1. Forty-five percent had a cutaneous vascular mark noted at birth. Thirty percent of the patients were asymptomatic and the lesions spontaneously involuted over time. The remaining 70% received therapy for symptomatic lesions. For most, treatment was performed to limit the size of the hemangioma and control ulceration. In the remaining patients, the indication for treatment was related to respiratory distress (26%), potential visual impairment (13%), congestive heart failure (4%), and obstruction of the auditory canal (3%).
Many hemangiomas will involute spontaneously, and watchful waiting is recommended in these cases. Symptomatic lesions or lesions causing significant cosmetic deformity can be treated. About 10-20% of hemangiomas present with indications for prompt therapy, such as expansion, destruction, obstruction, or life-threatening complications. Possible treatment options include corticosteroid or interferon injections, surgical excision, laser ablation, and embolization.