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Pleomorphic Adenoma of the Infratemporal Fossa:Case Report and Literature Review

Lowell E. Gurey, MD; Christopher D. Brook, BS; Steven M. Parnes, MDDivision of Otolaryngology- Head & Neck Surgery

Department of SurgeryAlbany Medical Center; Albany, NY

INTRODUCTION DISCUSSIONRESULTS

Figure 3. Anatomy of the infratemporal fossa. Reproduced from the 20th U.S. edition of Gray’s Anatomy of the Human Body. Public Domain.

ABSTRACTObjectives: To describe an unusual location for a common benign salivary gland neoplasm. Study Design: Case report and literature review. Methods: We describe an unusual lesion found in the infratemporal fossa on computed tomography of the facial skeleton, including the clinical presentation, workup, and surgical approach. A complete PubMed search of atypical presentations of pleomorphic adenoma was performed. The literature was also reviewed for all neoplasms involving the infratemporal fossa, pterygomaxillary fissure, and pterygopalatine fossa. Results: Pleomorphic adenoma has been reported to arise in such diverse locations as the nasal septum, main stem bronchus, trachea, lacrimal gland and external auditory canal. One case has been reported to occur in pterygopalatine fossa. No cases of pleomorphic adenoma involving the infratemporal fossa have been reported. There are, however, a number of other neoplasms that can arise, or more frequently, directly invade, this region. Malignancies can often have an insidious presentation that is initially referred to other disease entities. Conclusions: Though rare, there are a variety of neoplasms that can involve the infratemporal fossa. Patients with malignancies of this region usually present late in their disease course with invasion into surrounding structures. Diagnosis and approach to this region is difficult considering its concealed location.

Pleomorphic adenoma, or benign mixed tumor, is derived from the distal portions of the salivary ducts, including the intercalated ducts and acini. It is composed of a diverse population of cells demonstrating epithelial differentiation such as ductal structures with associated non-ductal elements. It also often contains cells of mesenchymal differentiation with areas of myxoid, hyaline, chondroid and osseous tissue (Fig 4).

It is most common neoplasm of the salivary glands and accounts for 40-70% of all neoplasms of the parotid, submandibular, and minor salivary glands; pleomorphic adenoma of the sublingual glands is rare. It has been reported to occur in any of the minor salivary glands which can appear throughout the upper and lower respiratory tract.

Embryologically, salivary glands are derived from outpouchings of the buccopharyngeal epithelium. The outermost strands of the glandular epithelium invade the connective tissue of the capsule. These may be responsible for ectopic salivary tissue.

Pleomorphic adenoma has been reported to appear in as diverse locations as the main stem bronchus, trachea, nasal septum, lacrimal gland, and the pterygopalatine fossa. It has also been reported to metastasize after multiple local recurrences, acting similar to a low-grade malignancy.

Complete surgical excision is the treatment of choice and should involve an adequate margin of uninvolved tissue.

Tumors of the infratemporal fossa present a surgical and diagnostic challenge because of the complexity of the local anatomy and the often occult nature of tumors harbored there. Tumors of the infratemporal fossa can be described as primary, secondary or metastatic. Adenoid cystic carcinoma, adenocarcinoma, and squamous cell carcinoma have been shown to be the most common malignant tumors of the infratemporal fossa with nasopharyngeal fibroma frequently found in benign lesions. We report the first documented pleomorphic adenoma of the infratemporal fossa.

The infratemporal fossa is usually involved by tumors extending from the surrounding areas such as the paranasal sinuses, middle cranial fossa, nasopharynx, parotid, and the external auditory canal. Primary tumors of the infratemporal fossa are seen less frequently and metastasis to this area is extremely rare.

Due to it’s concealed location, tumors often present late. Clinical signs and symptoms are insidious and are frequently attributed to other structures or disease.

In addition, surgical planning is confounded by the close proximity to intracranial structures, the orbit, sinuses, and the nasopharynx.

A 42 year-old incarcerated male presented to our emergency department after being struck in the face with a ball during prison softball league. The patient suffered a minimally displaced fracture of the inferior medial aspect of his left orbit and was incidentally noted to have a homogenous density present in the left infratemporal fossa on computed tomography (Fig. 1).

METHODS AND MATERIALS

1. Cantrell RW, Kaplan MJ, Atuk NO, Winn HR, Jahrsdoerfer RA. Catecholamine-secreting infratemporal fossa paraganglioma. Ann Otol Rhinol Laryngol. 1984 Nov-Dec;93(6 Pt 1):583-8.

2. Cook HF, Miller R, Yamada R. Giant cell tumor of the infratemporal fossa: report of case. J Oral Maxillofac Surg. 1986 Aug;44(8):651-6.

3. Cummings Otolaryngology - Head & Neck Surgery. 4th ed. Mosby, 2004. 3698-9.

4. Doubleday LC, Jing BS, Wallace S. Computed tomography of the infratemporal fossa. Radiology. 1981 Mar;138(3):619-24.

5. Fitchett J, Luckraz H, Gibbs A, O'Keefe P. A rare case of primary pleomorphic adenoma in main bronchus. Ann Thorac Surg. 2008 Sep;86(3):1025-6.

6. Haque F, Babu SPH, Ahamed S, et al. Pleomorphic adenoma of the nasal septum. Ind J Radiol Imag. 2005 15:3:311-3.

7. Manucha V, Ioffe OB. Metastasizing pleomorphic adenoma of the salivary gland. Arch Pathol Lab Med. 2008 Sep;132(9):1445-7.

8. Shapshay SM, McCann CF, Ucmakli A et al. Diagnosis of infratemporal fossa tumors using percutaneous core needle biopsy. Head Neck Surg. 1979 Sep-Oct;2(1):35-41.

9. Tiwari R, Quak J, Egeler S, et al. Tumors of the infratemporal fossa. Skull Base Surg. 2000;10(1):1-9.

10. Eugene N. Myers Operative Otolaryngology - Head & Neck Surgery. 2nd ed. Elsevier, 2009. Chapter 8.

11. Atlas of Head & Neck Pathology. Bruce M. Wenig. 2nd ed. Elsevier. 2008. 584-91.

CONCLUSIONS

REFERENCES

Lowell E. GureyAlbany Medical CenterEmail: lowell.gurey@gmail.comPhone: (518) 262-5578

Christopher D. BrookAlbany Medical CollegeEmail: cdbrook@gmail.com

CONTACT

Figure 1. Axial & coronal images. A homogenous mass is present in the left infratemporal fossa. Bony remodeling of the posterior wall of the maxillary sinus is observed. No evidence of bony invasion.

Anterior antrostomy, also known as the Caldwell-Luc, was named after American and French surgeons who independently described the approach to the maxillary antrum thru the canine fossa more than a century ago. We performed a typical anterior antrostomy and continued our dissection thru the postero-lateral wall of the maxillary sinus in order to enter the infratemporal fossa (Fig. 2). The lesion was noted to be completely encapsulated and was easily identified. It was then dissected free from the surrounding adipose tissue and removed.

The infratemporal fossa is located posterolaterally to the maxilla and maxillary antrum (Fig. 3). It extends between the zygomatic arch and the squamous portion of the temporal bone. The posterolateral wall of the antrum forms the anterior wall of the fossa, which is limited, above, by the inferior orbital fissure and behind, by the pterygopalatine fossa. The lateral pterygoid plate forms the medial wall, while the undersurface of the greater wing of the sphenoid constitutes most of the roof. The squamous portion of the temporal bone contributes to the roof as well. The infratemporal crest divides the roof from the medial wall of the temporal fossa. Posterior borders of the fossa include the articular tubercle of the temporal bone, glenoid fossa and condyle, and styloid process. Posterioinferior lies the parapharyngeal space.

Figure 2. Intraoperative view of approach and tumor in infratemporal fossa after opening the posterior wall of the maxillary sinus.

Though rare, a variety of neoplasms can involve the infratemporal fossa. Patients with malignancies of this region usually present late in their disease course with invasion into surrounding structures. Diagnosis and approach to this region is difficult considering its concealed location.

Figure 4. Histology of pleomorphic adenoma demonstrating epithelial and mesenchymal cell components.