Rare Case of Pleomorphic Adenoma: A Case Report - IJMD

case reportRare Case of Pleomorphic Adenoma: A Case ReportSrinivasan H*, Loganathan Selvaraj**AbstractPleomorphic adenoma is a benign tumor originating from the mature salivary tissue. Ectopic pleomorphic adenoma is definedas an unusual presentation of pleomorphic adenoma in other sites except the major salivary gland and the minor salivary gland.Ectopic pleomorphic adenoma has been found in the soft tissue of the neck, in the skin of the external auditory canal, in thesubcutaneous layer of the nose, and in the lymph node of the mediastinum. Ectopic pleomorphic adenoma could appear dueto the metastasis, the neoplastic degeneration of the ectopic salivary tissue or the implantation after the surgery of a salivarygland tumor. We present a case of pleomorphic adenoma found in the superficial subcutaneous layer above the superficialmusculoaponeurotic system (SMAS) of the anterior border of masseter muscle over the body of the mandible area. The patienthad no history of trauma or surgery of the salivary tumor and no specific physical finding. No case of the ectopic salivarytissue or ectopic pleomorphic adenoma in the superficial subcutaneous layer of the anterior border of masseter muscle overthe body of the mandible area has been reported. This case could be a rare presentation of the ectopic pleomorphic adenomafrom the ectopic salivary tissue arising from the division of the parotid gland in early embryonic period.Key words: Pleomorphic adenoma, SMAS, salivary glandPleomorphic adenomas account for 40-70% ofminor salivary gland tumors. They may arisein unusual locations along the cheek, alongthe Stenson’s duct and in accessory parotid tissue,which is separated from the body of the gland, 4 in theparapharyngeal space arising either de novo or fromthe deep lobe of the parotid gland and extendingthrough the stylomandibular tunnel into theparapharyngeal space. 5 It may also develop in salivarygland inclusions within the lymph nodes in the neck. 4This is the first report in the English languageliterature of a pleomorphic adenoma presenting inthe superficial subcutaneous layer above the superficialmusculoaponeurotic system (SMAS) of the anteriorborder of masseter muscle over the body of themandible area. 2 A brief description of the surgicaltechnique is presented.*Reader**Senior LecturerDept. of Oral SurgeryPriyadarshini Dental College and Hospital, ChennaiAddress for correspondenceDr Loganathan SelvarajSenior Lecturer, Dept. of Oral SurgeryPriyadarshini Dental College and Hospital, ChennaiE-mail: drloganathans@gmail.comCase ReportA 33-year-old Asian-Indian female patient presentedwith swelling on the left side of the mandibleregion, first noted approximately one month prior topresentation. She also experienced occasional pain inthe region for the past two weeks. The patient’s pastmedical history was noncontributory.Extraoral examination revealed a mild facial asymmetryin the region of the left body of the mandible (Fig. 1).The skin over the region was not fixed to any underlyingstructures and was freely movable in all planes. Therewas no evidence of locoregional lymphadenopathy.Her mouth opening was within the normal range(30 mm).Intraoral examination revealed no abnormalities. Onpalpation, the swelling was tender. The overlying skinwas free of any surface change, ulceration, purulentdischarge or sinus tract. The swelling measured 40 mmin circumference.Radiological finding (Fig. 2) showed no destructionor erosion of adjacent mandible. Based on the clinicaland radiologic findings, the provisional diagnosis givenby the clinicians was lipoma or fibroma or vascularlesion. A 10 ml syringe with a wide bore needle was236 Indian Journal of Multidisciplinary Dentistry, Vol. 1, Issue 4, May-June 2011

Case ReportFigure 1 . Extraoral picture showing mild facial asymmetryon the left mandibular region.Figure 4. Picture showing the tumor dissected out.Figure 2. Radiological finding showing no destruction orerosion of adjacent mandible.Figure 5. Histopathological picture showing an encapsulatedlesion comprising of duct like spaces with eosinophiliccoagulum (10×, H&E stain)Figure 3. Picture showing the modified excision of thelesion.used to aspirate the contents of the swelling to assessif the swelling was a vascular lesion. The aspirationwas found to be negative.An excisional biopsy was performed through an extraoralincision under local infiltration anesthesia. Bluntdissection and excision of the lobulated mass was done(Figs. 3 and 4). The total tumor mass was dissectedout and wound was closed in layers. The excised tumormass fixed in formalin was sent for histopathologicalevaluation. On gross examination, the tumor massconsisted of eight pieces of tissue which measured5-20 mm 2 in size, with a whitish, faintly lobulatedand focally glistening cut surface. Histopathologyrevealed an encapsulated lesion comprising of ductlike spaces with an eosinophilic coagulum, surroundedby spindle-shaped and plasmacytoid cells in a dense,hyalinized connective tissue stroma. An area resemblingchondroid tissue was also evident. The histopathologicalfeatures were suggestive of pleomorphic adenoma.(Figs. 5 and 6). The patient is on a regular follow-upand is disease free till date.Indian Journal of Multidisciplinary Dentistry, Vol. 1, Issue 4, May-June 2011237

Case ReportFigure 6. Histopathological picture showing an arearesembling chondroid tissue (10×, H&E stain).DiscussionPleomorphic adenoma is a benign tumor originatingfrom the mature salivary tissue. Ectopic pleomorphicadenoma is defined as an unusual presentation ofpleomorphic adenoma in other sites except the majorsalivary gland and the minor salivary gland. Ectopicpleomorphic adenoma was found in the soft tissue ofthe neck, in the skin of the external auditory canal,in the subcutaneous layer of the nose, and in thelymph node of the mediastinum. Ectopic pleomorphicadenoma could appear due to metastasis, the neoplasticdegeneration of the ectopic salivary tissue, or theimplantation after the surgery of a salivary glandtumor. We discussed the previous cases of ectopicsalivary tissues and ectopic pleomorphic adenomas.This case could be a rare presentation of the ectopicpleomorphic adenoma from the ectopic salivary tissuearising from the division of the parotid gland in earlyembryonic period. 1 If a vascular tumor is suspected,an magnetic resonance imaging (MRI) angiography orconventional arteriography should be performed. If thepossibility of a vascular lesion is ruled out, a histologicstudy could be performed. 6 The histopathology of ourcase proved to be pleomorphic adenoma. Though, thereis an anatomic relationship between the deep lobe ofthe parotid gland and the mandible, the probability ofdeep lobe tumors spreading to the infratemporal fossaseems to be rare. 2 All these findings indicate that thetumor has arisen from an ectopic minor salivary glandwithin the subcutaneous layer. The most commonsite of a PA of the minor salivary glands is the palatefollowed by lip, buccal mucosa and floor of the mouth,tongue, tonsil, pharynx, retromolar area and nasalcavity. 6,7 Pleomorphic adenoma in the parapharyngealspace can arise either de novo or may arise in thedeep lobe of the parotid gland and extend throughthe stylomandibular tunnel into the parapharyngealspace. Tumors in the parapharyngeal space are rare andconstitute less than 0.5% of head and neck neoplasms.Of these, PA is the commonest benign tumor (40%). 8The elective treatment of a pleomorphic adenomais surgery. There are numerous surgical approaches,indicating the difficulty of access, accentuated bythe communications with the neighboring regions.The prognosis of a pleomorphic adenoma isgood. The patient is remaining disease free aftersurgical excision and is on a regular follow-up.ConclusionIn summary, we are reporting the first case ofpleomorphic adenoma presenting in the superficialsubcutaneous layer above the SMAS of the anteriorborder of masseter muscle over the body of themandible area.References1.2.3.4.5.6.7.8.Tsukuno M, Nakamura A, Takai S, Kurihara K.Subcutaneous pleomorphic adenomas in two differentareas of the face. Scand J Plast Reconst Surg Hand Surg2002;36(2):109-11.Chung JH, Burm JS, Oh SJ. An ectopic pleomorphicadenoma in the superficial subcutaneous layer of thepreauricular area. J Korean Soc Plast ReconstrSurg32002;29(2):115-7.Shafer WG, Hine MK, Levy BM. Spread of oralinfection. In: a Textbook of Oral Pathology. 4th editionWB Saunders Co. 1997:513.Ellis GL, Auclaire PL, Gnepp DR. SurgicalPathology of Salivary Gland. WB Saunders Co:Philadelphia 1991:166.Rodriguez-Ciurana J, Rodado C, Saez M, Bassas C.Giant parotid pleomorphic adenoma involving theparapharyngeal space: report of a case. J Oral MaxillofacSurg 2000;58(10):1184-7.Eveson JW, Cawson RA. Tumour of the minor(oropharyngeal) salivary glands: a demographic study of336 cases. J Oral Pathol 1985;14(6):500-9.Cohen MA. Pleomorphic adenoma of the cheek. IntJ Oral Maxillofac Surg 1986;15(6):777-9.Batsakis JG, Sneige N. Pathology consultation:parapharyngeal and retropharyngeal space diseases. AnnOtol Rhinol Laryngol 1989;98(4 Pt 1):320-1.238Indian Journal of Multidisciplinary Dentistry, Vol. 1, Issue 4, May-June 2011