Clinical Pathologic Conference Cases presented at the Annual Meeting of the American Academy of Oral and Maxillofacial Pathology, June22-27, 2012

Fig. 2. Anterior view demonstrating slight weakness of the facial nerve involving the right upper lip. CLINICAL PATHOLOGIC CONFERENCE CASE 1: A WOMAN WITH A LUMP IN HER CHEEK PR Morgan, B Accurso, King’s College London Dental Institute, London, UK, and St. John Clinical Pathology Laboratories, Grosse Pointe Woods, Michigan, USA Clinical Presentation: A 30-year-old woman presented with a painless lump in her right cheek. She reported that it had been present for 3-4 months and had noticed gradual enlargement. She was otherwise healthy and her medical history was noncontributory. On examination, the lump measured 3 cm in diameter and had a slightly multinodular architecture (Figure 1). The overlying skin was slightly erythematous. Head and neck examination demonstrated no palpable cervical or submandibular lymph nodes; however, mild ipsilateral facial nerve weakness was noted (Figure 2). A fine needle aspiration biopsy (FNAB) revealed atypical squamous cells. Differential Diagnosis: Given the location, a salivary gland neoplasm, specifically a pleomorphic adenoma, was initially considered. Pleomorphic adenomas are the most common of the salivary gland neoplasms, occur slightly more frequently in women than men, and tend to be multinodular or lobulated. They can have squamous features, and the atypical squamous cells noted on the FNAB and nerve weakness would be supportive of a carcinoma ex-pleomorphic adenoma. However, this particular location was also thought to be somewhat too far anterior for any type of salivary gland neoplasm. Cutaneous neoplasms, although rare in the head and neck, should also be considered. Dermatofibrosarcoma protuberans is a rare cutaneous neoplasm, of which about 15% of cases occur in the head and neck region. It is also known to occur at nearly any age, have a multinodular architecture, and have slight erythema of the overlying skin. However, the majority of tumors exhibit slow but persistent growth over several years, in contrast to the history of this lesion. Soft tissues lesions such as nodular fasciitis and solitary fibrous tumor, although not common, are well known to occur at head and neck sites. Nodular fasciitis is a benign pseudotumor that can occur anywhere in the body, but will occur approximately 20% of the time in the head and neck region. It is also more commonly located in the head and neck region in young adults. Because of its rapid growth rate, it is often mistaken for a malignant process. Additionally, atypical epithelial or squamoid features on FNAB have been reported in nodular fasciitis. Unlike this case, the majority of reported cases of head and neck nodular fasciitis occur on the scalp and not the cheek or buccal mucosa. Solitary fibrous tumor is a benign neoplasm that, in a recent review of 142 head and neck examples, was shown to occur most often in the buccal mucosa. It is primarily a tumor of adults, affects both sexes equally, and presents as a painless enlarging mass. Interestingly, in a case series of 21 oral cavity solitary fibrous tumors, a striking predilection (81%) for the right side was reported.