Significance of Asymptomatic Tonsil Asymmetry

Abstract

OBJECTIVE: Asymmetry of tonsils that arouses suspicion for malignancy is one of the indications for tonsillectomy. The purpose of this study was to evaluate the incidence of occult malignancy in patients with asymptomatic unilateral tonsillar enlargement.

STUDY DESIGN AND SETTING: A prospective controlled trial was carried out in two institutions, Beyoglu Research and Training Hospital and Karaelmas University Hospital, during a 6-year period. Of patients selected for tonsillectomy, patients with unilateral tonsillar enlargement were identified and were included in this study. Patients who had risk factors that were significant for malignancy were excluded. After excision, two tonsil specimens were measured before sending for histology. Matched controls with symmetric tonsils underwent the same procedures. Preoperative diagnosis of tonsil asymmetry with the postoperative histologic diagnosis were correlated for the incidence of malignancy.

RESULTS: Of the 792 patients undergoing tonsillectomy, 53 patients (6.69%) with asymmetry of tonsils and who had no other risk factors for malignancy underwent tonsillectomy. The size difference of the tonsils ranged from 0 to 19 mm. In the control group of 51 patients with symmetric tonsils, the size difference ranged from 0 to 8 mm. The analysis showed statistically significant difference in the degree of asymmetry between the two groups (^P < .001). Most of the specimens contained reactive lymphoid hyperplasia in both groups (58.49% and 54.9%, respectively). No malignancies or unusual pathological findings were encountered on histologic examination in either group.

CONCLUSION AND SIGNIFICANCE: Tonsil asymmetry may only be apparent in patients with an otherwise normal physical examination, secondary to benign hyperplasia or anatomical factors. Therefore, the presence of tonsil asymmetry without factors such as suspicious appearance, significant systemic signs and symptoms, progressive enlargement of the tonsil, concomitant neck adenopathies, and history of malignancy or immunocompromise, may not indicate malignancy, as a sole clinical feature.

Squamous cell carcinomas of tonsils comprising approximately 85% of the malignant tonsillar neoplasms may present with unilateral enlargement or ulceration of mucosa. They may look identical in appearance to lymphomas and can only be distinguished by pathologic examination. Lymphoma is the second most common malignancy of tonsils and usually presents with a submucosal mass in an asymmetrical enlargement of one tonsil. 1 In fact, in patients without cervical adenopathy and other signs of malignancy, it is difficult to determine the presence of tonsil malignancy depending on the size.

The main indications of tonsillectomy are recurrent infection, peritonsillar abscess, obstructive sleep apnea, and suspicion of malignancy. When a tonsil is thought to be site of a neoplasm, biopsy, either by incisional or tonsillectomy approach, is essential. But is it logical to perform a tonsillectomy when a patient is found to have a unilaterally enlarged tonsil with an otherwise normal physical examination? The purpose of this study was to evaluate the incidence of occult malignancy in patients with asymmetrical tonsils with an otherwise normal physical examination.

PATIENTS AND METHODS

The study comprised 53 patients (22 female and 31 male patients, 5 to 34 years of age, mean age, 16.4 years) with tonsillar asymmetry, scheduled for tonsillectomy. The control group comprised 51 patients (20 female and 31 male patients, from 4 to 35 years of age, with a mean age of 17.8 years) with diagnosed hypertrophy of tonsils without asymmetry. Any patient with known risk factors significant for malignancy, such as presence of neck adenopathies, systemic signs and symptoms, fever, night sweats, dysphagia, weight loss), suspicious appearance of the tonsil, history of malignancy or immunocompromise was excluded from study. Suspicious appearance was defined as mass, ulceration or areas of abnormal pigmentation. On examination, details of tonsil size were noted using the classification of Brodsky: 4+ if the tonsils occupied greater than 75% of the airway, 3+ if they occupied 50% to 75%, 2+ if they occupied 25% to 50% of the airway, and 1 + if they occupied less than 25% of the airway. Any noted difference (at least 1+) between the right and left sides was considered a case of asymmetric tonsils. Tonsillectomy was performed using the dissection and snare technique. The surgeon recorded the size of the two excised tonsil specimens taking the maximal diameter. All of the specimens were subjected to microscopic histologic evaluation. Data were recorded in a Microsoft Excel database. The study group and the control group tonsil measurements (degree of asymmetry = size difference between the two tonsils) were compared by using two-tailed paired Student's t test. Results were considered to be significant at a level of P < .05.

RESULTS

Of the 792 patients undergoing tonsillectomy during the 6-year period, 53 patients with asymmetry of tonsils and who had no other risk factors for malignancy were identified and underwent tonsillectomy. The indications for tonsillectomy in this group were chronic tonsillitis in 25 patients (47.16%), tonsil hypertrophy with obstruction (sleep disorders, snoring) in 9 patients (16.98%), and recurrent tonsil infection with hypertrophy in 19 patients (35.84%). Thirty-one of the specimens (58.49%) contained reactive lymphoid hyperplasia on microscopic examination. Other pathologic findings were lymphoid hyperplasia with fibrosis in 8 cases (15%) and chronic tonsillitis in 14 cases (26.4%).

The control group consisted of 51 matched patients with no risk factors for malignancy, and who had symmetric tonsils. These patients underwent the same procedures as the patients with asymmetry of tonsils. The indications for surgery were chronic tonsillitis in 23 patients (45.09%), tonsil hypertrophy with obstruction in 10 patients (19.6%), and recurrent tonsil infection with hypertrophy in 18 patients (35.29%). There was no difference in size in 29 (56.8%) cases in this group. The specimens showed reactive lymphoid hyperplasia in 28 cases (54.9%), lymphoid hyperplasia with fibrosis in 12 cases (23.5%), and chronic tonsillitis in 11 cases (21.5%).

All cases except two in the asymmetric group had 25% degree (1+ according Brodsky classification) of asymmetry noted in the clinically assessed size on the physical examination. Two cases were determined to have more than 25% degree of asymmetry. The analysis showed statistically significant difference in the degree of asymmetry between the two groups (P < .001). The size difference of the tonsils ranged from 0 to 19 mm in the asymmetric group and from 0 to 8 mm in the symmetric group. On the measurement of the two tonsil specimens, in 21 cases (39.62%) of the asymmetric group there was no difference in size, whereas in 29 cases (56.8%) of the symmetric group the tonsils were similar in size.

No malignancies or unusual pathological findings were encountered in either group on histopathologic examination.

DISCUSSION

It is not unusual for the tonsils to be somewhat different in size. Even if the asymmetry of the tonsils has a harmless nature, a tumor growth is always considered when thinking of the differential diagnosis. Other than malignancy, chronic infections, such as tuberculosis, actinomycosis, repeated inflammation, lipid storage disease, benign tumors, and pathologies of the adjacent tissues may cause unilateral tonsil enlargement.

Some authors have suggested that all unilaterally enlarged tonsils should be considered for excision to exclude a malignancy without other suspicious features at presentation. 2 , 3 Conversely, other researchers have proposed waiting for observation when other suspicious clinical features are lacking because of the low incidence of malignancy in the case of unilaterally enlarged tonsils. 4 , 5

Spinou et al 6 noted that no lymphomas or carcinomas were identified in a series of 47 pediatric cases with unilateral tonsil enlargement. In 17% of their cases, clinically enlarged tonsil was actually the smaller of the two when measured and they noted no difference in size in 17 (40%) patients. Similarly, in a controlled study, Harley 5 reported no malignancy in 47 children who had some degree of tonsillar asymmetry. This author noted that there were no statistical differences in the size of the tonsils in the two groups (asymmetric and symmetric), when measured by volume. On the other hand, Harley concluded that the apparent asymmetry resulted from the depth of the tonsillar fossa.

As mentioned by many authors, unilateral tonsil enlargement is generally a result of the asymmetry of the anterior tonsillar pillars. Berkowitz and Mahadevan 4 found that in 52% of the children subjected to tonsillectomy for apparent unilateral tonsil enlargement, the tonsils were similar in size. They compared this group of children who had unilateral tonsil enlargement with an other group of children who were diagnosed to have lymphoma. They noted that 86% of the children with lymphoma had systemic symptoms or cervical adenopathy at presentation, whereas the other group showed no symptoms or adenopathies.

In the present study, on the measurement of the maximal diameter of tonsils there was no difference in size in 39.62% of the asymmetric group and in 56.8% of the symmetric group. This means that even in tonsils that clinically appeared symmetric, there often was some asymmetry. On the other hand, interestingly, tonsil asymmetry was apparent in 21 patients of the asymmetric group with tonsils that were, in fact, similar in size. This may be explained by the difference in the depth of the tonsillar fossa or by asymmetry of the anterior tonsillar pillars.

In the adult population, Reiter et al 7 reported two malignancies (6.5%), both unilateral diffuse large-cell lymphomas, in 31 patients who underwent tonsillectomy for tonsillar asymmetry or lymphoma workup. These authors noted that they excluded the tonsils with suspicious appearance (focal tonsillar mass or ulceration) from this group, but the data concerning the other clinical signs and symptoms suggestive of malignant disease were not available. This was found to be the case in the study of Dohar and Bonilla,⁸ who reviewed 2,012 pediatric patients and discovered only one case of lymphoma suspected before surgery on the basis of asymmetry between the two tonsils.

Importantly, other than significant asymmetry as a probable determining factor for malignancy, criteria mentioned as abnormal gross appearance, presence of neck adenopathies, suspicious systemic symptoms, and history of malignancy or immunocompromise were excluded in the study and control groups. Contrary to other studies, the analysis showed statistically significant difference in the degree of asymmetry between the two groups (P < .001). In this way, only the asymmetry could be exactly taken into consideration and, as a result, no malignancies were found in either group on histopathologic examination. On the other hand, this finding shows that preoperative clinical impressions correlate well with the microscopic examination of tonsil specimens.

The present study comprised adult and pediatric patients. The most common pathological diagnosis was lymphoid hyperplasia in both groups of the study. This may support the view that tonsil asymmetry is usually secondary to benign hyperplasia. Finally, an observation period may be appropriate before the decision for surgery.

CONCLUSION

Tonsillar asymmetry may be simply a result of anatomic conditions such as a difference in the depth of tonsillar fossa or asymmetry of the anterior tonsillar pillar. Chronic granulomatous infections, glycogen or lipid storage disorder, and benign tumors other than malignancy may be encountered in the case of rapid enlargement. In the absence of other suspicious features, asymmetric tonsils may not indicate a malignancy. A detailed investigation and an observation period may prevent unnecessary tonsillectomies.

I thank Cevdet Altinyazar, MD (Zonguldak Karaelmas University) for statistical analysis.

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