Pedunculated cribriform adenocarcinoma of the base of the tongue.

Abstract

A handful of cases of cribriform adenocarcinoma of the tongue have been reported in the literature, but in none of these cases was the tumor pedunculated. By the time these patients sought treatment, most of the tumors had metastasized to the cervical lymph nodes. We report the case of a 65-year-old woman who had a large, pedunculated, cribriform adenocarcinoma that had arisen from the base of the tongue. This case was also unusual because the tumor had not metastasized. The patient was treated with surgery and radiotherapy. To the best of our knowledge, cribriform pedunculated adenocarcinoma of the base of the tongue has not been previously reported.

Introduction

Cribriform adenocarcinoma of the tongue is a rare malignant tumor that originates in the tongue base. Most of these tumors are locally aggressive, and by the time patients seek treatment, most of the tumors have metastasized to the cervical lymph nodes. In this article, we report a case of cribriform adenocarcinoma of the base of the tongue that was unusual in that the mass was pedunculated and it had not metastasized. To our knowledge, a pedunculated tumor in such a case has heretofore not been reported.

Case report

A 65-year-old woman came to our institution with a 15-day history of dysphagia, breathing difficulty, and a "hot-potato voice." The onset of the dysphagia had been gradual, and she was able to take only a semisolid diet. Examination of her oral cavity and oropharynx revealed the presence of a smooth, globular, pedunculated, 6 x 6cm mass that had arisen from the base of the tongue toward the right side (figure 1). The mass moved up and down when the patient gagged. The surface of the mass contained a whitish slough of necrotic tissue in two places. The mass was firm in consistency and did not bleed when touched. On indirect laryngoscopy, the mass blocked the view of the laryngeal inlet. The remainder of the ENT examination was normal. There were no palpable neck nodes.

[FIGURE 1 OMITTED]

Because the patient had been experiencing a choking sensation and because the mass was pedunculated, we decided to take an excision biopsy with the patient under general anesthesia via oral endotracheal intubation. The patient was placed in Rose's tonsillectomy position, and a Boyle Davis mouth gag and Draffin bipod stand were employed. The pedicle of the tumor was attached to the base of the tongue between the median and lateral epiglottic folds (figure 2). A thread was passed around the globular mass toward the pedicle, the pedicle was ligated, and the tumor was excised (figure 3).

[FIGURE 2-3 OMITTED]

The mass was sent for histopathologic examination, and the patient's postoperative period was uneventful. According to the histopathologist, the outer surface of the mass was covered with ulcerated mucosa, and the cut surface had lobulated, gray-white appearance. Microscopically, ulcerated squamous epithelium was seen, as were underlying lobules of tumor tissue that were arranged predominantly in microcystic cribriform, tubular, and solid patterns (figure 4). In the solid areas, the peripheral cells were characterized by a palisading arrangement. The cribriform spaces and tubular lumina were focally filled with mucin. Focally, a distinct papillary pattern with a fibrovascular cote was seen. Cytologically, the tumor was made up of one cell type; characteristically, a single layer of columnar cells with clear-to-pink cytoplasm and overlapping single, pale, vesicular nuclei with a ground-glass appearance was seen. Nucleoli were inconspicuous, mitotic figures were infrequent, and there was no spindle-cell differentiation.

[FIGURE 4 OMITTED]

Periodic acid-Schiff and alcian blue (pH: 2.5) stains showed strongly positive mucin staining in the microcystic and tubular lumina, and they highlighted the fine cribriform spaces in the solid areas. Based on these histopathologic findings, the tumor was diagnosed as a cribriform adenocarcinoma. Three weeks postoperatively, the patient underwent a full course of radiotherapy (total dose: 60 Gy). At the 18-month follow-up, she was symptom-free.

Discussion

Squamons cell carcinoma is the most common malignant tumor of the base of the tongue. Minor salivary gland neoplasms account for 1% of all tongue base tumors, and most are benign. The most common malignant tumor of the minor salivary glands is adenocarcinoma.

Clinicopathologic features. As we continue to learn more about adenocarcinomas of the salivary glands, a number of entities with some common clinicopathologic features are being identified. Among them are polymorphous low-grade adenocarcinomas, lobular carcinomas, terminal duct carcinomas, and low-grade papillary adenocarcinomas. (1)

Polymorphous low-grade adenocarcinoma of the salivary gland was first recognized as a distinct entity in 1983. (2) Prior to then, this disease had been mistakenly classified as lobular carcinoma or terminal duct carcinoma because of its microscopic resemblance to lobular carcinoma of the breast or a presumed origin in the terminal salivary duct, respectively. In 1984, Evans and Batsakis proposed the term polymorphous low-grade adenocarcinoma. (3) Since then, this term has been widely used in the literature, and it was eventually adopted by the World Health Organization in its revised classification of salivary gland neoplasms. (2)

The spectrum of growth patterns in polymorphous lowgrade adenocarcinoma includes solid nests and trabeculae, tubules, papillae, cysts, cribriform or pseudoadenoid cystic formations, strands, and fascicles. Combinations and transitions among these patterns are common. (3) The neoplastic cells in polymorphous low-grade adenocarcinoma grow in a combination of two or more of these five basic architectural patterns: (1) tubules and ductlike structures, (2) cords and trabeculae, (3) solid nests, (4) cribriform pattern with pseudoluminal spaces, and (5) papillae. Most cases involve three patterns: tubules and duct-like structures, cords and trabeculae, and solid nests. Perez-Ordonez et al reported that cribriform areas were present in only 35 % of the cases they studied and that they were always seen in combination with at least one of the more common patterns. (4)

Michal et al proposed the term cribriform adenocarcinoma of the tongue to describe a distinctive type of adenocarcinoma that has usually metastasized to the cervical lymph nodes by the time patients seek treatment. (2) They also hypothesized that this tumor might arise from the thyroglossal duct analage. In their series, a major portion of these lesions featured a solid and microcystic growth pattern. The most striking cytologic feature was that the tumor nuclei were pale-staining, they had a ground-glass quality, and they appeared to overlap and resemble both solid and follicular variants of papillary thyroid carcinoma. On immunohistochemistry, these tumors expressed cytokeratin and S100 protein and focal actin, suggesting that there was a myoepithelial differentiation with negative thyroglobulin. (2)

Histopathologically, the tumor in our patient exhibited features of cribriform adenocarcinoma of the tongue. However, we found no evidence of myoepithelial differentiation. The differential diagnoses that we considered included polymorphous low-grade adenocarcinoma, primary or metastatic papillary thyroid carcinoma, and adenoid cystic carcinoma. We excluded polymorphous lowgrade adenocarcinoma based on the lack of a wider range of architectural pattern and the presence of ground-glass nuclei. We ruled out papillary thyroid carcinoma on the basis of the polypoid nature of the tumor, the strong mucin positivity, the absence of deeply eosinophilic colloid, and the presence of a normal thyroid. Adenoid cystic carcinoma was discounted because the characteristic collagen deposition was not seen. Also, in adenoid cystic carcinoma, the cells are basaloid and contain dark, hyperchromatic, and angulated nuclei.

Clinical manifestations. Cribriform adenocarcinoma of the tongue base usually appears as a poorly circumscribed, nonpedunculated mass. Patients generally relate a history of dysphagia or odynophagia. The interesting features of out case were that the tumor was globular with a pedicle arising from the base of the tongue and that there was no cervical node metastasis. Histopathologically, however, it was identified as a cribriform adenocarcinoma.

Grewal et al described the basis for such a pedicle formation. (5) They wrote that pedicle formation can be the result of the laxity of the tissues at the base of the tongue; the constant movement of the tumor during swallowing, breathing, and coughing; the weight of the tumor; and a patient's failure to seek treatment until respiratory distress develops. The presence of a pedicle usually causes a reduction of the blood supply to the tumor as a result of torsion or kinking; this was seen in our patient, who had a whitish slough of necrotic tissue in two places. Because our patient's pedicle was located between the median and lateral epiglottic folds, we believe that her tumor might have actually arisen from the thyroglossal duct analage.

Management. Local excision with postoperative radiotherapy was very effective in our case. A simple method of passing the thread around the tumor and ligating the pedicle resulted in a bloodless operation. Our decision to prescribe radiation was based on the experience of Armstrong et al, who recommended it on the basis of their experience with tumors of the major salivary glands. (6)

References

(1.) Dardick I, van Nostrand AW. Polymorphous low-grade adenocarcinoma: A case report with ultrastructural findings. Oral Surg Oral Med Oral Pathol 1988;66:459-65.

(2.) Michal M, Skalova A, Simpson RH, et al. Cribriform adenocarcinoma of the tongue: A hitherto unrecognized type of adenocarcinoma characteristically occurring in the tongue. Histopathology 1999;35:495-501.

(3.) Evans HL, Batsakis JG. Polymorphous low-grade adenocarcinoma of minor salivary glands. A study of 14 cases of a distinctive neoplasm. Cancer 1984;53:935-42.

(4.) Perez-Ordonez B, Linkov I, Huvos AG. Polymorphous low-grade adenocarcinoma of minor salivary glands: A study of 17 cases with emphasis on cell differentiation. Histopathology 1998;32: 521-9.

(5.) Grewal DS, Pusalkar AG, Phatak AM. Pedunculated pleomorphic adenoma of the tongue base manifesting with dyspnoea. A case report. J Laryngol Otol 1984;98:425-7.

(6.) Armstrong JG, Harrison LB, Spiro RH, et al. Malignant tumors of major salivary gland origin: A matched-pair analysis of the role of combined surgery and postoperative radiotherapy. Arch Otolaryngol Head Neck Surg 1990;116:290-3.

From the Department of Otolaryngology-Head and Neck Surgery, Kasturba Medical College, Mangalore, India.

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