Учебники / Textbook and Color Atlas of Salivary Gland Pathology - DIAGNOSIS AND MANAGEMENT Carlson 2008

Figure 10.11l. The exposed palatal bone is covered with immature granulation tissue at 1 month postoperatively.

Figure 10.11m. Immature granulation tissue underwent maturation by 3 months postoperatively as seen in this image.

Figure 10.11n. At 1 year postoperatively, the patient’s defect has demarcated well.

Figure 10.11o. A defi nitive obturator has been fabricated. Reprinted with permission from Carlson ER. 1995. Salivary gland pathology—clinical perspectives and differential diagnosis. In: The Comprehensive Management of Salivary Gland Pathology, Oral and Maxillofacial Surgery Clinics of North America 7. Philadelphia: W.B. Saunders, pp. 361–386.

neurovascular bundle should be sampled for frozen sections superiorly. Since perineural spread is not characteristic of this tumor, it is unlikely to find tumor tracking along the nerve, in contradistinction to adenoid cystic carcinoma, where tumor may be found surrounding this nerve at foramen rotundum. An immediate surgical obturator is fabricated preoperatively for insertion at the time of

Figure 10.12a. A biopsy-proven polymorphous low-grade adenocarcinoma of the palate in a 53-year-old woman that had been present for several years, according to the patient.

ablative surgery so as to permit the patient to begin taking a diet on the day of surgery. If the bone is eroded by the tumor, a traditional maxillectomy is necessary, also resulting in a full thickness sacrifice of the soft palate (Figure 10.12). An immediate surgical obturator must also be fabricated preoperatively for insertion at the time of surgery when a maxillectomy is planned for this diagnosis.

Figure 10.12c. A maxillectomy was performed, observing 1 cm linear margins in bone and soft tissue.

Figure 10.12e. The histopathology confirmed the involvement of the maxillary bone by the tumor.

Figure 10.12f. The large ablative defect.

Figure 10.12g. The large ablative defect was addressed with an immediate obturator.

Figure 10.12h. At 1 year postoperatively, the patient showed no signs of recurrent disease.

The surgical treatment of polymorphous lowgrade adenocarcinoma of the upper lip or buccal mucosa is similar to that of a mucoepidermoid carcinoma of these regions. The basic approach involves a mucosal-sacrificing wide local excision with attention to submucosal anatomic barriers being included on the specimen so as to ensure tumor-free margins (Figure 10.13).

The use of radiation therapy has been assessed in the management of polymorphous low-grade adenocarcinoma. In a clinicopathologic study of 164 cases of this malignancy, 17 patients underwent incisional, excisional, or wide local excision followed by radiation therapy (Castle, Thompson, and Frommelt et al. 1999). Adjuvant radiation therapy did not affect survival. Their study showed that patients who were treated with radiation therapy were more likely to have evidence of disease at last follow-up when compared with patients who did not have radiation therapy. Furthermore, there was no statistically significant difference in the overall patient outcome based on the type of initial treatment given or for any additional treatment rendered, whether it was additional surgery, radiation therapy, or chemotherapy. Based on this report and others (Crean et al. 1996), the treatment for polymorphous low-grade adenocarcinoma of minor salivary glands remains surgi-

cal. It has been estimated that approximately 80% of patients survive their disease without evidence of tumor at periods from between several months to 25 years after removal (Wenig and Gnepp 1991). One case has been reported where death occurred as a result of this neoplasm with direct extension to vital structures of the head (Aberle, Abrams, and Bowe et al. 1985). In addition, while rare, metastasis to cervical lymph nodes (Kumar, Stivaros, and Barrett et al. 2004) and to distant organs (Hannen, Bulten, and Festen et al. 2000) has been reported from polymorphous low-grade adenocarcinomas originating in the palate. These reports indicate that cervical lymph node involvement should be suspected in patients with papillary cystic change in the tumor, and that periodic chest X-ray examination should be performed postoperatively when this variant of tumor is diagnosed.

Figure 10.13e. The specimen was able to be delivered without tumor spillage.

Figure 10.13f. The defect was reconstructed with a split thickness skin graft and a sialodochoplasty of Stenson’s duct.

Figure 10.13g. Acceptable healing is noted without tumor recurrence at 6 months postoperatively. Reprinted with permission from Carlson ER. 1995. Salivary gland pathol- ogy—clinical perspectives and differential diagnosis. In: The Comprehensive Management of Salivary Gland Pathology, Oral and Maxillofacial Surgery Clinics of North America 7. Philadelphia: W.B. Saunders, pp. 361–386.

Acinic Cell Adenocarcinoma

Acinic cell adenocarcinoma is a very rare malignancy of the minor salivary glands. It has been estimated to represent approximately 2.5–3% of salivary gland tumors in general (Guimaraes et al. 1989; Spiro 1986) and about 4% of minor salivary gland tumors (Castellanos and Lally 1982). Indeed, acinic cell adenocarcinoma is not represented in many studies of minor salivary gland tumors (Chau and Radden 1986; Isacsson and Shear 1983; Jaber 2006), and other studies show only a very limited number of these cases (Lopes et al. 1999; Toida, Shimokawa, and Makita et al. 2005). The acinic cell adenocarcinoma behaves most similarly to the low-grade mucoepidermoid carcinoma (Ord 1994). In fact, like the low-grade mucoepidermoid carcinoma, the acinic cell adenocarcinoma was originally purported to be a benign neoplasm (Ellis and Auclair 1991a). For the first half of the twentieth century, these tumors were thought to be benign. In 1953, Buxton and his group were the first to ascribe a malignant character to many of these tumors (Buxton, Maxwell, and French 1953). These were identified as serous cell adenocarcinomas, after which time Foote and Frazell classified these

tumors as acinic cell adenocarcinomas (Foote and Frazell 1953).

The AFIP registry shows 886 acinic cell adenocarcinomas, of which 753 were located in the major salivary glands (85%), and 133 (15%) in the minor salivary glands. The most common site of minor salivary gland involvement was the buccal mucosa, accounting for 43 cases (32%), followed by the lip (38 cases, 29%). Tumors in the upper lip were three times more common than tumors in the lower lip. The palate was the only other significant anatomic site to be affected by this tumor, and accounted for 22 cases (17%). A female preponderance was noted, with a mean age of 44 years.

Surgery for acinic cell adenocarcinoma is performed in a similar fashion as that of low-grade mucoepidermoid carcinoma. Tumors of the buccal mucosa and upper lip are treated with mucosalsacrificing wide local excisions, including 1 cm linear margins, with attention to the necessary sacrifice of surrounding anatomic barriers (Figure 10.14). Tumors of the palate can be treated with bone-sparing, periosteally sacrificing wide local excisions with split thickness sacrifice of the soft palate. Computerized tomograms may be obtained preoperatively to confirm the lack of bone erosion. Recurrences and regional and distant metastases are rare when these malignancies are treated according to these recommendations. Five and 10year survival rates are generally quite favorable and reported as 82% and 68%, respectively (Hickman, Cawson, and Duffy 1984).

Epithelial-Myoepithelial Carcinoma

The epithelial-myoepithelial carcinoma of minor salivary gland origin has been categorized as an intermediate-grade malignancy according to the AFIP classification (Ellis and Auclair 1991b). Only 57 cases were identified in their series, with 50 cases diagnosed in the major salivary glands (88%), and 7 cases (12%) in the minor salivary glands (Corio 1991). Of the 7 cases in the minor salivary glands, 4 were located in the palate, 1 in the tongue, and 2 cases were not specified as to anatomic location. A mean age of 59 years was noted in these 57 cases. This tumor is known to be highly differentiated, yet it is malignant due to infiltrative and destructive growth patterns, the presence of necrosis, perineural involvement, and metastases (Corio et al. 1982). Corio et al. pre-

a

b

Figures 10.14a and 10.14b. An acinic cell adenocarcinoma of the right buccal mucosa in a 52-year-old patient. The histopathology of the biopsy shows a typical blue dot tumor (b).

Figure 10.14c. A mucosal-sacrifi cing wide local excision observing 1 cm linear margins is performed.

Figure 10.14d. Excision of the specimen occurred without tumor spillage.

Figure 10.14e. The defect was reconstructed with mucosal fl aps so as to not distort the appearance of the upper lip.

Figure 10.14f. Acceptable healing without tumor recurrence is noted at 1 year postoperatively.

sented 16 cases of this neoplasm and found 12 cases to involve the parotid gland, 3 cases in the submandibular gland, and 1 case in the buccal mucosa (Corio et al. 1982).

Standardized recommendations for surgery for the epithelial-myoepithelial carcinoma are difficult to make due to the rare nature of this malignancy. Nonetheless, evaluation of involved anatomic barriers with physical examination and

CT scans generally permits an effective approach to eradication of these malignancies in various minor salivary gland sites (Figure 10.15). In such circumstances, the surgeon respects well-estab- lished principles of linear and anatomic barrier margins when operating on salivary gland tumors, while also relying on past experience with other lowand intermediate-grade minor salivary gland malignancies. In so doing, tumor-free margins can

Figure 10.15i. Final histopathology showed destruction of bone by the cancer.

Figure 10.15j. The specimen radiograph demonstrated acceptable bone margins.

k

l

Figures 10.15k and 10.15l. The resultant ablative defect of the maxilla (k) was reconstructed with an immediate obturator device (l).