Cytodiagnosis of pleomorphic adenoma in ectopic salivary gland in neck: a case report

¹Department of Pathology, Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha, Maharashtra 442004, India

^&Corresponding author
Kaustubh Kharche, Department of Pathology, Jawaharlal Nehru Medical College, Sawangi (Meghe), Wardha, Maharashtra 442004, India

Introduction    

The ectopic salivary glands are known to be located in the upper anterior triangle of the neck and mostly recognized accidentally on surgical examination [1,2]. These ectopic salivary tissues usually present as nodular swellings at many other locations as could be predicted by its embryological development. Many times, these nodules of ectopic salivary tissue confuse as lymph nodes, the thyroglossal cysts and branchial cysts on palpations. Histopathologically such tissue is either diagnosed as choristoma or ectopic salivary lobules or gland [1-3].

The tumors within these ectopic salivary are very rare. The literature search showed that ectopic salivary harboring benign or malignant neoplastic lesions are rarely reported. The presently reported case is a unique surgical pathology where in a nodular swelling in the upper neck region was diagnosed as the ectopic salivary gland harboring the lesion of pleomorphic adenoma upon the fine needle aspiration cytology (FNAC) and histopathology of surgically excised specimen. Diagnosis of pleomorphic adenoma in ectopic salivary tissue on FNAC are rare in literature [3-6]. We present a case of pleomorphic adenoma in ectopic salivary gland in neck diagnosed on cytology.

Patient and observation     

Patient information: an 18-year-old female reported to out patient´s department of surgery of university attached Acharya Vinoba Bhave rural hospital with complaints of swelling in upper right of neck in anterior triangle.

Clinical findings: the swelling was painless but was progressive. The patient noticed the swelling two years back which has progressed to the present size of 2.5 x 1.5 cm. The swelling was painless and showed restricted mobility (Figure 1). It was globular in shape and non-translucent. The bilateral neck examination revealed no such swellings or lymph nodes. The swelling was unassociated with fever or any other systemic manifestation. Her intraoral examination was normal.

Differential diagnosis: the clinical diagnosis of isolated lymphadenopathy was entertained and the patient was advised to undergo the ultrasonographic examination (USG) of the swelling. She was also subjected to complete blood counts. The clinicians advised the fine needle aspiration cytology (FNAC) of the swelling.

Diagnostic assessment

Radiological and hematological investigations: meanwhile patient underwent the sonography of the swelling which revealed a well-defined heterogeneously hypoechoic lesion with minimal vascularity within. Bilateral submandibular glands appeared normal on sonography. The thyroid gland was reported to be normal in size, shape, echotexture and separate from swelling. No lymphadenopathy was reported. The complete blood count revealed normal hematological parameters.

Cytology and diagnosis: the FNAC was carried out by standard methodology. The aspirated material was made to smears. It was fixed and processed for Papanicolaou and Giemsa staining. The microscopy of the stained preparation showed cellular smears. Smears showed multiple sheets, pseudo papillae and whorl of columnar to cuboidal epithelial cells placed in cohesion with spindle nuclear cells. Few cell sheets showed honeycombing. Nuclei showed moderate anisonucleosis, also showed intercellular fibrils and myxoid material along with pseudo plasmacytes and bare nuclei. Cytomorphological features were suggestive of cellular pleomorphic adenoma of ectopic salivary gland. No cytologically malignant cells were seen. The diagnosis of ectopic pleomorphic adenoma in heterotopic salivary gland tissue was offered (Figure 2, Figure 3). The histopathological assessment of the excised tissue was performed.

Informed consent: informed oral consent was obtained from the patient before conducting all the investigations of radiology as well as cytology and for further use of patient information for research purposes.

Discussion     

The locations of ectopic salivary tissue depend on the developmental embryology of the salivary gland. The hyperplasia within it appears like nodular tumors. The ectopic salivary confuses clinically with the primary tumor of the native tissue within that anatomical area or the lymph nodes. Ectopic salivary tissue undergoing the neoplastic change is rare. The clinicians often refer them as ectopic adenoma.

These tumorous nodules undergo the excision for its treatment. However, modern day practice of pre operative diagnosis of tumorous lesions by FNAC offers the surprise diagnosis such of pleomorphic adenoma within ectopic salivary. The reports of cytodiagnosis of pleomorphic adenoma in ectopic salivary by FNAC are rare [3-5]. The cytomorphology of pleomorphic adenoma within ectopic shows similar cytomorphological characters as that of pleomorphic adenoma within normal salivary glands of parotid or submandibular salivary glands. The diagnostic feature of pleomorphic adenoma on fine needle aspirates are presence of cuboidal epithelial cells in cohesion placed in the monolayered cell sheets and papillaroid structure. The myoepithelial cells are seen within these sheets of cells. The cell sheets show honeycombing. It is associated with fibromyxoid and chondromyxoid stromal fragments along with bare nuclei. Many times, the cuboidal cells appear like pseudo plasmacytes and oncocytic changes in the cytoplasm. The present case had all these cytomorphological features which are also been reported by other authors [1,3-6].

The implications of the diagnosis of ectopic salivary tissue and pleomorphic adenoma within ectopic salivary tissue holds the importance for surgical management of such tumorous lesions. The preoperative diagnosis offers precise surgical management as has been offered in the present case. The unilateral slowly growing firm masses typically in areas where ectopic of salivary in upper neck can exist should evoke the clinical suspicion of ectopic salivary tissue and lesions within it [1]. The present case is unique for reasons of its locations of ectopic salivary harbouring the lesion of pleomorphic adenoma.

Conclusion     

The FNAC of pleomorphic adenoma within ectopic salivary tissue is a rare diagnosis. This case report will enrich the literature over it and the values of FNAC for preoperative diagnosis in exclusion of such unique instances.

Competing interests     

The authors declare no competing interests.

Authors' contributions     

Three authors contributed for the overall workup of this case. Patient management: Kaustubh Kharche. Data collection, manuscript drafting and Manuscript revision: Kaustubh Kharche, Arvind Bhake, Ankita Gyanchandani. All the authors have read and agreed to the final manuscript.

Figures     

Figure 1: ectopic salivary; the swelling of size 2.5 x 1.5 cm located in right anterior triangle (encircled area)

Figure 2: pleomorphic adenoma; pseudo papillaroid sheets of cuboidal epithelial cells with myoepithelial cells and hyaline material; (fine needle aspiration cytology (FNAC), papanicolaou (PAP), 40x)

Figure 3: pleomorphic adenoma; fragment show admixed tissue of cuboidal benign sheet of epithelial cell in close proximation to fibromyxoid material; (fine needle aspiration cytology (FNAC), Giemsa, 40x)

References