Perinatal salivary gland tumours (embryomas)

Pediatric sialoblastoma: Evaluation and management

OBJECTIVES

Sialoblastoma is a rare congenital salivary gland tumor of epithelial origin. The objectives of this study are to review the literature regarding clinical presentation of sialoblastoma, evaluate the effectiveness of various treatment methods, and present guidelines for evaluation and management in the pediatric population.

DATA SOURCES

Case presentation and literature review.

REVIEW METHODS

A comprehensive search was conducted to identify cases of pediatric sialoblastoma in the English-language literature. The presentation, evaluation, and management of reported cases were analyzed. We also report an invasive and recurrent case in a pediatric patient to highlight the aggressive nature of these lesions.

RESULTS

Sixty-two cases of pediatric sialoblastoma were reviewed. The age at initial presentation ranged from before birth to 15 years. The parotid gland was the most common location (n = 47). Surgical excision was the primary treatment in all patients. Nine patients developed metastatic disease of the lung, lymph nodes, or bone. Almost a third of patients had recurrence and over two thirds of patients were tumor-free for at least 1 year following their last treatment intervention.

CONCLUSION

Prompt and complete surgical excision should be recommended to prevent local and systemic recurrence of pediatric sialoblastoma. Chemotherapy has also shown promise in several cases, and clinical genomics may shed light on more therapy options. Patients should be closely followed for at least 12 months following diagnosis, or longer depending on the histopathological staging of the tumor.

Sialoblastoma of the parotid gland in a 13-year-old girl with multiple recurrences and long-term follow-up

BACKGROUND

Sialoblastoma is an extremely rare congenital salivary gland tumor of epithelial origin. It is usually localized in the parotid or submandibular gland and presents primarily at birth or in early childhood.

METHODS

We report a case of a 13-year-old girl with a sialoblastoma of the parotid gland presenting as an asymptomatic painless mass.

RESULTS

The patient showed multiple recurrences and, based on the histopathological finding of facial nerve infiltration, was treated surgically with total parotidectomy and facial nerve reconstruction.

CONCLUSION

Because of the rare occurrence of sialoblastoma, there is no evidence-based treatment of choice. The treatment should be individualized, taking into consideration the patient's age, the high locoregional recurrence rate, the local aggressive characteristics, and the potential metastatic activity of this rare tumor. A close follow-up of the patient is strongly recommended.

Sialoblastoma: A literature review from 1966-2011

Sialoblastoma is a rare congenital tumour of the salivary glands arising mainly from the parotid gland. It is usually diagnosed at birth or shortly thereafter with a significant variability in histological appearance and clinical course. In extensive search of PubMed indexed journals, we got 46 cases of "sialobalstoma/embryoma/congenital basal adenoma", with one case was of German literature and three additional cases of adult sialobalstoma. This article has extensively reviewed the clinical, histopathological and immunohistochemical features, Magnetic resonance imaging (MRI) and Computerized Tomography (CT) findings, treatment and prognosis.

Surgical excision of sialoblastoma in the parotid gland in newborn

OBJECTIVES

To evaluate outcome of surgical excision of sialoblastoma in the parotid gland in newborn.

PATIENTS AND METHODS

This was a retrospective review of 3 pediatric patients with sialoblastoma in the parotid gland that underwent surgical resections. All patients are newborn boys. The lesions ranged from 5 cm × 5 cm to 8 cm × 5 cm in size. The tumor was resected en bloc, and the facial nerve was preserved.

RESULTS

None surgical complications occurred. The mean follow-up was 34 months; none patients had recurrent lesions.

CONCLUSION

Surgical dissection of sialoblastoma in the parotid gland in the newborn is most efficient and safe.

Sialoblastoma- long-term follow-up and remission for a rare salivary malignancy

Sialoblastoma is a rare salivary neoplasm which presents either congenitally or during early infancy. It was originally considered a benign neoplasm, however a number of reported cases have documented locoregional recurrence and distant metastases. Currently, there is no consensus on the appropriate treatment for this neoplasm. We report on long term follow-up of a patient with metastatic sialoblastoma, and a brief discussion of the possible treatment modalities currently being considered.

Congenital minor salivary gland sialoblastoma: a case report and review of the literature

Sialoblastoma is the most common epithelial tumor of the salivary gland. We report a case of congenital sialoblastoma arising in a minor salivary gland of the buccal mucosa of a male infant. After radiologic evaluation, an incisional biopsy was performed and then the mass was excised en bloc. Histologic features were both favorable and unfavorable. However, there was no recurrence for 5 months. In spite of a reported histologic grading system, the clinical course of isolated sialoblastoma is considered unpredictable. More published case reports of this rare tumor may enable histologic and clinical correlation in order to accurately predict prognosis.

Management of sialoblastoma with surgery and brachytherapy

Sialoblastoma is a rare congenital or perinatal salivary gland tumor with significant variability in histological appearance and biological behavior. We reported one case of sialoblastoma occurring in the parotid gland of an 18-month-old female. The tumor was excised with negative margins, and the sacrificed facial nerve was reconstructed with great auricular nerve graft. The tumor recurred 6 months after operation and was treated with (125)I seed implant brachytherapy. No recurrence was found after 21 months of follow-up.

How to manage an unresectable or recurrent sialoblastoma

Only 2-5% of all salivary gland tumors occur in children. Sialoblastoma is an extremely rare salivary gland tumor diagnosed at birth or shortly thereafter with significant variability in histological range and clinical course, so that it may be difficult to predict the most appropriate therapy. In cases where surgical removal is not curative or technically feasible, chemotherapy may be attempted. We report herein a patient with progression of a huge partially resected sialoblastoma who was successfully treated with chemotherapy. Systemic chemotherapy with vincristine, actinomycin D, and cyclophosphamide (VAC) seems to be an effective adjuvant or neoadjuvant treatment option for unresectable or recurrent sialoblastoma.

Sialoblastoma in adults: distinction from adenoid cystic carcinoma

Essentially, sialoblastoma is a disease of infancy with the oldest case presenting at 4 years of age. About one third of pediatric sialoblastoma cases will have a cribriform growth pattern. No adult cases have been reported with a specific diagnosis of sialoblastoma. If even focal cribriforming were present, such cases have undoubtedly been diagnosed as adenoid cystic carcinoma. Such was the circumstance in the 3 adult tumors presented in this report. Each case, however, has the primitive histopathology with discrete nests of basaloid tumor cells, associated bilayered ductal structures and the fibromyxoid stroma characteristic for sialoblastoma with its resemblance to fetal salivary gland or salivary gland with arrested development. One key example has 28-year follow-up. Sialoblastoma, whether in a child or adult with or without a cribriform growth pattern, appears to have a more favorable prognosis than adenoid cystic carcinoma. Aspects of the histological differential diagnosis of these 2 tumors are discussed.

Sialoblastoma

Sialoblastoma should be considered in the diagnosis of a perinatal neck swelling that appears to be contiguous with the submandibular salivary gland. These are exceedingly rare perinatal salivary tumors of epithelial origin with variable biologic behavior including the potential for local and systemic recurrence. We report the case of a 3-month-old boy who presented with a submandibular swelling of insidious onset that was initially thought to be a lymph node enlargement.

An eyelid sialoblastoma-like tumor with a sarcomatoid myoepithelial component

Nonround cell tumors are rare in children and often difficult to diagnose. This article describes an 18-month-old child who presented with a mass on the outer aspect of the left eyelid. This mass was incompletely excised. Histologically, the tumor had nests of basaloid and relatively round cells with immature acinar or ductular structures similar to those seen in a conventional sialoblastoma, but these nests were embedded in a malignant spindle cell stroma. This stroma on immunohistochemistry was marked with S-100 and cytokeratin, which, in combination with the pertinent ultrastructural evidence, indicated a myoepithelial differentiation. Overall histologic features suggested a tumor similar to a sialoblastoma with sarcomatoid transformation of the myoepithelial component, hitherto not described in literature. This tumor probably arose from the palpebral lobe of the lacrimal gland. Postsurgery, the patient received chemotherapy (6 cycles of ifosfamide, vincristine, and doxorubicin hydrochloride [Adriamycin]) and local radiotherapy in view of residual disease. Three months after completion of the treatment (1 year after surgery), the patient is well, without any local disease. Awareness of this unusual histology of sialoblastoma will help in avoiding misdiagnosis and also refine treatment-related issues on this rare tumor.

Paediatric salivary gland epithelial neoplasms

Salivary gland epithelial neoplasms in children are rare. Clinicians of all disciplines need to have a high level of suspicion when a non-inflammatory single mass lesion presents in the parotid or submandibular glands. There is high likelihood of malignancy when such a mass presents. Surgery is the primary treatment of choice in the majority of cases, with the addition of adjuvant radiotherapy +/- chemotherapy when the diagnosis is a high-grade tumour and/or when the malignancy presents as a large mass or is associated with local tissue invasion. Minor salivary gland neoplasms also present, the oral cavity is most frequent, with pleomorphic adenoma and mucoepidermoid carcinoma being most common, other malignant neoplasms have been reported in other sites.

Pediatric salivary gland lesions

The salivary glands comprise three main pairs of glands (ie, the parotid, the submandibular, and the sublingual) and a number of minor glands found in the mucosa of the upper aerodigestive tract. Lesions may be inflammatory or obstructive in nature or may stem from granulomatous or neoplastic disease. As such, establishing a definitive diagnosis is often quite challenging. This article reviews widely used diagnostic approaches and briefly describes various salivary gland lesions within an etiologic framework.

Sialoblastoma

Tumours of the salivary gland are very uncommon in children. We present a case of sialoblastoma, a very rare congenital salivary-gland tumour, initially recognised on antenatal ultrasound. After histological diagnosis, a superficial parotidectomy was performed at 21 days of age with preservation of the facial nerve. There is no recurrence at2 years.

Sialoblastoma of the submandibular gland: report of a case and review of the literature

Sialoblastomas are rare perinatal epithelial salivary tumors, with only 22 reported cases in the literature. While they have been reported to occur predominantly in the parotid gland, we present one case of sialoblastoma of submandibular gland origin. The surgical management of this patient is discussed. Histopathologic examination, including immunochemical, ultrastructural and cytogenetic studies, was performed. Pertinent literature is reviewed.

Diagnostic and therapeutic approach to sialoblastoma: report of a case

The natural history of a rare parotid tumor, the sialoblastoma (embryoma) is reported. It is a blastematous neoplasm said to recapitulate the epithelial differentiation of a gland at various stages of development. The tumor grew in a period of 5 years (from shortly after birth until it was excised) to a firm asymptomatic mass measuring 5 cm in greatest diameter. With a diagnosis of adenoid cystic carcinoma (a common misdiagnosis), the patient was referred to the reporting institution, where the diagnosis was revised. Five months later, completion parotidectomy for presumed recurrence failed to demonstrate residual tumor. One year later, the patient appears to be free of disease. The authors propose that sialoblastomas should be regarded neither as benign nor malignant, but as one single disease with local infiltrative potential. Based on this concept, sialoblastomas can be treated with early conservative surgery alone, provided that free margins are obtained.

Sialoblastoma: clinicopathological/immunohistochemical study

Sialoblastoma is an extremely rare salivary tumor diagnosed at birth or shortly thereafter with significant variability in histologic range and clinical course, so that for an individual case it may be difficult to predict the most appropriate therapy. We detail the case of a toddler noted to have a firm 1-2-cm mass in the left cheek at 21 months. Parotidectomy was performed at 26 months, revealing a sialoblastoma; the resection margins were positive. During the next 10 months, the mass recurred or persisted, necessitating numerous procedures. The tumor was composed of basaloid cells with fine chromatin and other more mature cuboidal epithelial cells. Ductules and solid organoid nests with some tendency toward peripheral pallisading were also noted. There was no perineural invasion; necrosis initially was sparse but increased over time. The mitotic rate also increased from 6 to 7/10 high-power fields in the first resection to 20/10 high-power fields in the last resection. Nuclear pleomorphism increased with time. The MiB1 proliferative index revealed a dramatic increase in the number of labeled nuclei: from 3 cells/10 high-power fields in the first specimen to 94 cells/10 high-power fields for the last specimen. Cytokeratin accentuated the ductal structures. S-100 showed a diffuse staining pattern, with darker staining of the spindled myoepithelial cells. The Her-2-neu protein showed moderate cytoplasmic staining, whereas the p53 showed only occasional labeling of nuclei. This is the first case of sialoblastoma with evidence of increasing anaplasia based on increasing proliferative capacity. Therefore, the distinction between benign and malignant sialoblastomas may not be as well defined as previously thought. The patient's prognosis is likely to be determined by the tumor grade as well as the stage at presentation and the extent of resection.

The congenital basal cell adenoma of salivary glands. Contribution to the differential diagnosis of congenital salivary gland tumours

Congenital epithelial tumours of the salivary glands are very rare. The Salivary Gland Registry maintained in the Department of Pathology. University of Hamburg, contains only three cases among a total of 6,646 salivary gland tumours from the years 1965-1994. The three cases were classified as congenital basal cell adenoma, two of the parotid gland and one of the submandibular gland. Histologically, the three adenomas were similar in structure to the adult counterpart of basal cell adenoma with solid, trabecular or tubular (duct-like) patterns. In some cystic spaces of the duct-like structures PAS- and Astra blue-positive substances were secreted. On immunocytochemistry, the luminal duct-like cells showed membranous expression of cytokeratins 3, 5, 6, 7, 13 and 19. In the isomorphic basaloid cells of the solid and trabecular cell nests few cells expressed cytokeratin. On the outside of the solid cell nests there were smaller elongated myoepithelial-like cells, which expressed cytokeratin 14 and vimentin. Cytokeratins 1, 2, 4 and 18 were not expressed. The pattern of expression reflects the different stages of maturity of the tumour cells and is related to the development of the salivary glands until the end of the 3rd embryonal month with an arrest of further cell differentiation. No acinic cells, invasive growth, recurrence or metastases were observed. The differential diagnosis includes other congenital salivary gland tumours, such as hybrid basal cell adenoma-adenoid cystic carcinoma, sialoblastoma or embryoma, carcinoma, hamartoma and teratoma.

Embryoma (sialoblastoma) of salivary glands

There are four clinicopathologic categories of the exclusively major salivary gland tumors that present in the perinatal period. The two with the smallest representation among the 20 cases reported to date are those with a hamartomalike appearance and those with benign adult equivalents--the pleomorphic and monomorphic adenomas. Five cases have been undifferentiated or basaloid salivary carcinomas. Embryomas (sialoblastomas) are the most numerous. These tumors manifest a histologic phenotype like that of the epithelial anlage of the salivary glands, albeit in an arrested state of differentiation.

Troublesome tumours 2: borderline tumours of salivary glands

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Epithelial salivary gland tumors of children and adolescents in southern Portugal. A clinicopathologic study of twenty-four cases

During a 30-year period 24 epithelial salivary gland tumors were diagnosed in children and adolescents less than 18 years of age. The cases were retrieved from a series of 759 consecutive cases of salivary gland tumors (3.2%) from the area corresponding to southern Portugal during the same period of time. The mean age of the patients was 13.4 years, and one case was congenital. There was a slight female predominance (male/female ratio 1:1.7). The parotid gland was affected in most cases (70.8%). Seventeen neoplasms were benign, and the remaining seven were malignant. As in the adult group, pleomorphic adenoma was the most frequent benign tumor (66.6%), with similar histologic findings and clinical course. Mucoepidermoid carcinoma was the prevalent malignant tumor (20.8%), had a high grade of differentiation, and had a favorable outcome. The histologic pattern of the congenital neoplasm was similar to that of adult epithelial-myoepithelial carcinoma.

Salivary gland tumors in children

Fewer than 5% of all primary salivary gland neoplasms occur in children, but if benign supporting tissue tumors are excluded, a higher proportion than in adults are malignant. The first decade of life, and particularly the first 2 years of life, has a preponderance of benign neoplasms. Commencing with the second decade, carcinomas rise in incidence and are most often mucoepidermoid and acinic cell carcinomas. The pleomorphic adenoma is the most common epithelial salivary tumor throughout childhood. The embryoma may be a uniquely childhood epithelial salivary gland tumor.