Salivary gland heterotopia or choristoma consists of the presence of salivary gland tissue outside the major and minor salivary glands. It is a rare disease, usually congenital, secondary to the persistence and abnormal development of vestigial structures1,2.

A 53-year-old woman with no past history of interest reported the appearance in childhood of a nodular lesion in the right lower anterior cervical region that had been growing slowly and gradually. The lesion occasionally exuded a clear, odorless liquid, frequently in association with eating. The examination revealed a soft nodule measuring 9 mm in diameter, with overlying light-brown skin, located on the right sternoclavicular joint. It was associated with a small central orifice with no active draining on pressing (Fig. 1A and B). Ultrasound revealed a well-defined nonencapsulated hypoechoic subcutaneous lesion with no clear fistular tracts and with no vascularization in the Doppler study (Fig. 2). The lesion was excised and the histopathology study revealed aggregates of salivary gland tissue made up of mucous and serous glands, accompanied by a discrete ductal excretory component, located in the subcutaneous cell tissue (Fig. 3A,B). It presented isolated foci of lymphocytic inflammatory infiltrate. These findings led to a diagnosis of salivary gland heterotopia. The patient remained asymptomatic during follow-up, with no signs of recurrence.

Figure 1.

Right supraclavicular nodular lesion.

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Figure 2.

Ultrasound study with well-defined nonencapsulated, hypoechoic subcutaneous lesion.

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Figure 3.

In subcutaneous cellular tissue, aggregates of salivary gland tissue made up of mucous and serous glands.

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Salivary gland heterotopia is a rare disease, associated with abnormal development of the branchial apparatus, and only small series or isolated cases have been reported in the literature. The pathogenesis is unknown but the most widely accepted hypothesis suggests that it is due to defective closure of the precervical sinus within the branchial apparatus. It usually manifests at birth or in early childhood as a nodular, cystic, or fistulized lesion that is asymptomatic except for the occasional secretion of a fluid similar to saliva, predominantly located on the lower anterior part of the sternocleidomastoid muscle, with a predilection for the right side1,2. Other reported locations are the mandibular region, the middle ear, the sella turcica, the parathyroid glands, the mediastinum, and the rectum3–8. Although rare, bilateral presentation is also possible2. Histology shows mucous and/or serous salivary gland structures, often with an associated ductal component (dilated, collapsed, or absent) and chronic periductal inflammation. Its association with other congenital anomalies is very rare2.

Surgical treatment is indicated for diagnostic purposes and to prevent inflammatory processes and potential neoplastic degeneration. In fact, in the largest series available in the literature, with 24 cases of salivary gland heterotopia, associated malignant tumors were found in 6 cases (3 mucoepidermoid tumors, 2 acinar cell carcinomas, and 1 adenocarcinoma)9. While malignancy in a heterotopic area must be considered in cases of salivary gland carcinoma outside the salivary glands, metastatic dissemination should also be ruled out2,9,10. While no data exist in the literature, ultrasound may be particularly useful in the differential diagnosis with other more common diseases and in preoperative planning. Based on our case and the literature, in the event of a nodular lesion in a typical location, with secretion and with ultrasound showing no characteristics of a cystic lesion, we must include salivary gland heterotopia in the differential diagnosis.