Pediatric parotideomasseteric pilomatrixoma in children

Abstract

Aims. To review definitive histological diagnoses of patients with great salivary gland tumors with focus on the relatively high incidence of pediatric pilomatrixomas. The authors focus on clinical investigation, imaging methods and fine needle aspiration cytology of pilomatrixomas. Methods. We treated 12 children with great salivary gland masses aged from 6 months to 18 years from 1995 to 2010. The records of these patients were reviewed to determine sex, age, clinical presentation, and histological findings. Results. Among children having true neoplasms, there was a prevalence of carcinomas (6 out of 9), with low-grade mucoepidermoid and acinic cell carcinomas (two each) as the dominating histopathological diagnosis. There was one adenoid cystic carcinoma and one curious undifferentiated carcinoma in a 6 month old baby. Among all 6 benign lesions, accounting for a half of the total, pilomatrixoma was the most common (2 out of 6) diagnosis, representing 17% (2 out of 12) of all salivary gland lumps and 66% (2 out of 3) of all true benign neoplasms. Conclusions. Pilomatrixoma should be included in the differential diagnosis of pediatric parotideomasseteric lumps. Clinical investigation reveals adherence to the skin but not to the underlying tissue. Clinical assessment and ultrasound guided fine needle aspiration cytology in typical findings strongly support the diagnosis. Cytopathologists must be aware of the preliminary diagnosis of a pilomatrixoma to use proper fixation of the smears. In doubts, frozen biopsy must be sent before parotidectomy is performed.

A lesson learnt: retrospection in a case of pilomatricoma mimicking as parotid neoplasm

“…Thus, FNAC might have more basophilic cells in the lesion in early stages while keratinocytes might predominate in later stages, so that the lesion can be misrepresented as malignant in both stages. 4 The problem is complicated by the fact that the parotid region is one of the most common topographic areas with involvement of head and neck pilomatricomas, 1 , 5 - 7 which also increase the dilemma of clinicians and pathologists because pilomatricoma is seldom considered as a differential diagnosis for a mass lesion involving this region. In fact, some reports on FNAC from such lesions had suggested parotid neoplasm, 5 or even metastatic malignant deposits.…”

“… 4 The problem is complicated by the fact that the parotid region is one of the most common topographic areas with involvement of head and neck pilomatricomas, 1 , 5 - 7 which also increase the dilemma of clinicians and pathologists because pilomatricoma is seldom considered as a differential diagnosis for a mass lesion involving this region. In fact, some reports on FNAC from such lesions had suggested parotid neoplasm, 5 or even metastatic malignant deposits. 6 Because surgeons relying greatly on cytology in clinically suspected parotid tumors, such approach have resulted in more aggressive surgical treatment.…”

“… 6 Because surgeons relying greatly on cytology in clinically suspected parotid tumors, such approach have resulted in more aggressive surgical treatment. 5 , 6 , 8 …”

“…Portanto, a CAAF pode ter mais células basófilas em lesão em estágio recente enquanto os queratinócitos podem ser predominantes em estágios mais tardios, sendo interpretada, erroneamente, como tumor maligno em ambos os estágios. 4 O problema é complicado ainda mais em razão da parótida ser uma das áreas topográficas mais comuns com envolvimento do pilomatricoma na região de cabeça e pescoço, 1 , 5 - 7 que também aumenta o dilema dos clínicos e patologistas já que o pilomatricoma é raramente considerado no diagnóstico diferencial para massa envolvendo essa região. Na verdade, há relatos de que a CAAF dessas lesões sugeriu neoplasia da parótida, 5 ou mesmo lesões malignas metastáticas.…”

“… 4 O problema é complicado ainda mais em razão da parótida ser uma das áreas topográficas mais comuns com envolvimento do pilomatricoma na região de cabeça e pescoço, 1 , 5 - 7 que também aumenta o dilema dos clínicos e patologistas já que o pilomatricoma é raramente considerado no diagnóstico diferencial para massa envolvendo essa região. Na verdade, há relatos de que a CAAF dessas lesões sugeriu neoplasia da parótida, 5 ou mesmo lesões malignas metastáticas. 6 Em razão dos cirurgiões se basearem amplamente na citologia em casos de suspeita clínica de tumores na parótida, tal abordagem tem resultado em tratamentos cirúrgicos mais agressivos.…”