Ectopic goiter masquerading as submandibular gland swelling: a case report and review of the literature

Ectopic thyroid glands generally occur in the midline as a result of abnormal median migration, and their presence lateral to the midline is rare. A 12-year-old boy had a swelling in the left submandibular region that imaging techniques showed to be an ectopic thyroid gland, although no thyroid tissue was seen in the normal location. Only eight cases of lateral aberrant thyroid tissue have been reported. The importance of being aware of the possibility of ectopic thyroid tissue as a submandibular region swelling has an important bearing on disease management. A pertinent review of the literature and its management is included.     

Assessment of age-related morphological and functional changes of selected structures of the head and neck by computed tomography, magnetic resonance imaging, and positron emission tomography

The head and neck is a complex anatomical region that can be evaluated using many imaging modalities. It is important to discern normal structures from ones that are affected by disease and to study how these structures change in their morphological and functional properties with aging. Therefore, using magnetic resonance imaging (MRI), we retrospectively evaluated volumes of the parotid glands, submandibular glands, thyroid gland, tongue, soft palate, and lingual tonsils in 64 subjects ages 13 to 81 years. Volume, attenuation (HU), and metabolic activity (maximum SUV) of the parotid, submandibular, and thyroid glands were assessed retrospectively using positron emission tomography/computed tomography (PET/CT) imaging in 35 subjects ages 10 to 76 years. Metabolic activity (maximum SUV) of the parotid, submandibular, and sublingual glands; tongue; adenoids; and tonsils (lingual and palatine) were evaluated retrospectively using PET imaging in 15 subjects ages 6 to 20 years. Metabolic volumetric products of the parotid, submandibular, and thyroid gland were calculated and analyzed with increasing age in subjects who underwent PET/CT imaging. Structures that exhibited statistically significant changes (P < 0.05) with increasing age included the submandibular glands, thyroid gland, soft palate, and adenoids. The CT volume of the submandibular glands increased with age, and the attenuation decreased with age with statistical significance. The thyroid gland volume, as measured using MRI, showed a statistically significant decrease with aging. The volume of the soft palate and lingual tonsils, as measured by MRI, exhibited a statistically significant decrease in volume with aging. The maximum SUV of the adenoids demonstrated a statistically significant decrease with aging. In conclusion, CT, MRI, and PET may be used to quantitatively and qualitatively assess structures of the head and neck and are useful in the assessment of structural and functional changes of these structures with aging.     

Double thyroid ectopia (with incidental papillary thyroid microcarcinoma) (2010: 8b)

We present the case of a 45-year-old man with a long-standing history of a slow-growing left submandibular mass. Imaging was diagnostic as it disclosed an absent orthotopic thyroid gland and heterogeneous masses, with both solid and cystic components, as well as calcifications in the left sublingual/submandibular space and in the left paramedian aspect of the tongue base, consistent with double thyroid ectopia, originating from central and lateral thyroid anlages, respectively. Pathology confirmed an ectopic thyroid goiter in the left submandibular space with an incidental papillary microcarcinoma. Scintigraphy also demonstrated ectopic thyroid tissue in the left tongue base.     

Normal values of [99mTc]pertechnetate uptake and excretion fraction by major salivary glands

The assessment of the functional status of the salivary glands has been used in the scintigraphic evaluation of xerostomia. Several quantitative methods derived from standard dynamic scintigraphy have been suggested. However, the indices proposed are quite variable and unlikely to be useful in clinical practice.The objectives of this study were to obtain reference values of major salivary glands uptake and excretion fraction in healthy subjects and to obtain normal ratios of Tc-pertechnetate uptake by the major salivary glands in comparison to the thyroid gland uptake. The standardization of these values has the purpose of making this evaluation faster and more objective.Fifty volunteers without clinical evidence of xerostomia or thyroid disease underwent static salivary glands scintigraphy with Tc-pertechnetate. Static images were obtained at 20 minutes and then at 3 minutes after oral stimulation with lemon juice. Percent uptake, excretion fraction and salivary gland to thyroid ratio rates were calculated for the parotid and the submandibular glands.The mean of the uptake values at 20 minutes for the right and left parotid glands were respectively 0.31% and 0.26%, and for the submandibular glands 0.15%. The excretion fraction of the tracer after the lemon juice stimulation was 70% for the parotids glands, 50% for the right and 49% for the left submandibular glands. The mean+/-SD salivary gland to thyroid count ratio was 0.79+/-0.45 for the right parotid, 0.78+/-0.5 for the left parotid, 0.67+/-0.33 and 0.66+/-0.34 for the right and left submandibular glands, respectively.Salivary glands scintigraphy with uptake and excretion fraction calculation is an easy to perform, non-invasive and objective method to investigate salivary glands function. These findings help the nuclear physician to interpret salivary gland scintigraphy more objectively, even in patients with thyroid gland dysfunction in whom Tc-pertechnetate thyroid uptake may be abnormal.     

Scintigraphic visualization of glossal thyroid tissue during the follow-up of thyroid cancer patients

PURPOSE: Nests of thyroid tissue in the tongue are described in about 10% of necropsies. This ectopic thyroid tissue usually lies dormant, but may manifest itself during times of increased stimulation. The aim of our study was to assess the frequency of lingual thyroid visualization on I-131 diagnostic whole-body scan during the follow-up of thyroid cancer patients. MATERIAL AND METHODS: We reviewed the files of 548 consecutive patients who underwent a diagnostic whole-body scan with 200 MBq of I-131 between January 2000 and December 2005, as part of the follow-up for a differentiated thyroid cancer. Every patient had been previously treated with a total thyroidectomy and had received 3.7 GBq (100 mCi) of I-131 for remnant ablation. RESULTS: A focus of uptake located between the 2 submandibular salivary glands, suggestive of ectopic thyroid tissue in the tongue or in the upper part of the thyroglossal duct, was found in 5 of the 548 patients (0.9%). In only one of these patients was the uptake visible at the time of postsurgery thyroid remnant ablation scan. Thyroglobulin (Tg) levels were positive under stimulation in 3 of the 5 patients, and another patient had undetectable Tg, but positive anti-Tg antibodies. Radiologic imaging (MRI and/or ultrasound) was performed in 3 patients and confirmed the presence of a mass suggestive of ectopic thyroid tissue in two. Invasive lingual biopsy was not performed to verify the benign nature. CONCLUSION: When examining whole-body scans (therapeutic or diagnostic) in a patient with persistent Tg detection after thyroid ablation, one should carefully search for any uptake between the submandibular glands that may be suggestive of ectopic tissue.     

Rosai Dorfman disease of the parotid and submandibular glands: salivary gland scintigraphy and oral findings in two siblings

Rosai-Dorfman disease (RDD) is an unusual clinical entity characterized by benign pseudolymphomatous proliferation with significant histiocytic infiltration. In the present paper, extranodal RDD of the major salivary glands causing salivary hypofunction and the results of salivary gland scintigraphy and ultrasound are presented in two siblings. Case 1: a 10-year-old boy with bilateral painless masses around the parotid and submandibular glands was referred. Ultrasound examination showed bilateral, well-defined, hypoechoic solid mass lesions within both parotid glands with minimal normal parenchyma in the upper poles. Both submandibular glands were markedly hypoechoic and heterogeneous. Mass lesions within the parotid glands appeared as cold lesions with regular contours on scintigraphy. Dynamic images showed normal uptake and normal response to secretion in the upper poles of the parotid glands, corresponding with ultrasonographically normal parenchyma. Both submandibular glands showed markedly diminished uptake and secretion. Case 2: a 9-year-old boy presented with mass lesions around the submandibular glands. Ultrasound examination showed normal parotid glands and markedly hypoechoic and heterogeneous submandibular glands. Salivary gland scintigraphy showed normal uptake and secretion of parotid glands with markedly diminished uptake and secretion in both submandibular glands. There were severe carious lesions in both patients due to salivary hypofunction. Treatments of the two patients' teeth were performed. Major salivary gland involvement of RDD is important for dentists as it may cause xerostomia and can mimic dental abscess. Functional evaluation of salivary glands with scintigraphy, besides radiological and pathological techniques, will help to explain whether salivary glands are affected or not and improve the diagnostic effectiveness.     

Indium-111 leukocyte accumulation in submandibular gland saliva as a cause for false-positive gut uptake in children

Unexplained false-positive accumulation of In-111 leukocyte in the gastrointestinal tract has been reported previously. In a pediatric population, uptake in the submandibular gland was noted in 19 of 42 children. This is believed to be a normal finding in children that is not seen in adults. In some of these 19 children, unexplained gastrointestinal activity was also noted. Saliva from a patient with false-positive gastrointestinal uptake and positive submandibular activity was positive for In-111. One suggested cause of unexplained gut activity may be secondary to swallowed activity in the saliva from the normal submandibular activity in children.     

Semi-quantitative assessment of salivary gland function in patients with differentiated thyroid carcinoma after radioiodine-131 treatment

Sialadenitis and xerostomia are well-known side effects of high-dose radioactive iodine ((131)Iota) treatment in patients with differentiated thyroid carcinoma (DTC). This study was undertaken to determine salivary gland function semi-quantitatively in patients with DTC given (131)I for the treatment of the thyroid remnant and/or metastases. Thirty-six patients, 11 males and 25 females, mean age 53.5 years, range 22-73 years, were studied. Scintigraphy of the salivary glands was performed with (99m)Tc-pertechnetate and the salivary excretion fraction (SEF) of the parotid and the submandibular glands was calculated as a measure of their function. Measurements were performed before (131)I treatment as a baseline study, and three weeks and three months later. The patients were clinically evaluated by a standardized subjective questionnaire. Results were as follows: Mean SEF at three weeks and three months after (131)I treatment was reduced as compared to baseline measurements. The total mean baseline measurements, those of three weeks and those of three months later were: 54.9%, 47.2% and 46% respectively; P<0.05 for both measurements (Table 1). The SEF decrease of the parotid glands was greater than that of the submandibular glands (P<0.05 as compared for both salivary glands before and three weeks and three months after (131)I treatment). This confirmed the higher radiosensitivity of the parotid glands as compared to the submandibular glands. In 12 patients (33%) there was no significant decrease of SEF in the salivary glands after (131)I treatment. The relation between the decrease of SEF after three weeks and after three months and the dose of (131)I administered, was for the right and left submandibular glands significant (P=0.016 and P=0.002), while for the parotid glands it was insignificant (P=0.22 and P=0.27 respectively) (Table 4). Reduction of SEF in the parotid glands three months after (131)I treatment was greater than after three weeks. This difference, as regards the submandibular glands, was not significant. Our results show that high dose (131)I treatment in DTC patients induces a significant effect on salivary gland function, which is dose-related in the submandibular glands, and more prominent in the parotid glands.     

Computed tomography of the submandibular salivary glands

Computed tomography offers a convenient method for the evaluation of the submandibular salivary glands and their surroundings. Normal measurements were established based on 38 normal subjects. The visualization of the ductal system in the gland and the relationship of the gland to the platysma muscle were recorded. The CT scans of 12 patients with a tongue base carcinoma and 4 patients with a verified obstruction of the submandibular duct were also reviewed to establish how the glands are affected by extrinsic lesions. The normal glands measured 28 x 18 mm (+/- 5 mm) in the axial plane. Two patients with unilateral hypoplasia of the gland were found in the normal group. Visualization of the intraglandular duct is not a specific finding since it was observed in more than 25 per cent of the normal group. Displacement and bulging of the platysma muscle by the submandibular gland can be a sign of glandular enlargement. It was also seen in 9 out of 12 patients with carcinoma of the base of the tongue.     

MR of the submandibular gland: normal and pathologic states.

PURPOSETo evaluate the MR appearance of normal and pathologic states of the submandibular gland.METHODSMR images of 22 healthy subjects and 21 patients with histopathologically confirmed disorders of the submandibular gland (five pleomorphic adenomas, two hemangiomas, two malignant lymphomas, one adenoid cystic carcinoma, one squamous cell carcinoma, and 10 cases of sialadenitis) were reviewed.RESULTSAll normal submandibular glands showed higher signal intensity than surrounding muscle but lower intensity than fat on T1-weighted and T2-weighted images. Postcontrast images showed moderate enhancement of the gland. All the tumors had lower signal intensity than the normal submandibular gland on T1-weighted images and had intermediate to high (n = 8) or high (n = 3) signal intensity relative to the normal submandibular gland on T2-weighted images. Six of seven benign tumors were well defined, and three of four malignant tumors were poorly defined. In all cases of sialadenitis, the submandibular gland showed diffusely different signal intensities from the normal gland on both T1-weighted and T2-weighted images. Eight cases of chronic sialadenitis showed lower T2-weighted signal intensities than the normal gland, and this can be explained histopathologically by marked fibrosis and cellular infiltration.CONCLUSIONSMR imaging can show the presence, extent, margins, and signal intensity changes of pathologic conditions of the submandibular gland.     

Ultrasound findings of iodide mumps

Iodide mumps, swelling of salivary glands after contrast medium injection, is a rare adverse reaction. We present a case in a 73-year-old man with advanced gastric cancer. About 10 min after a CT scan performed with intravenous injection of 140 ml of the low osmolality contrast agent Ioxaglate (Hexabrix 320, Guerbet, France), he complained of progressive swelling of the submandibular area. Ultrasound showed diffuse swelling and internal low echoic thick septa in the submandibular glands bilaterally. Approximately 1 h afterwards, the swelling of his submandibular glands started to regress and returned to normal within a day.     

Amifostine is a Potent Radioprotector of Salivary Glands in Radioiodine Therapy

BACKGROUND AND PURPOSE: Salivary gland impairment following high-dose radioiodine treatment is well recognized. Since differentiated thyroid cancer has a good prognosis, reduction of long-term side effects is important. This study investigates the radioprotective effects of amifostine in salivary glands of rabbits receiving high-dose radioiodine therapy so as to obtain deeper insight in changes on the cellular and ultrastructural level. MATERIAL AND METHODS: A total of 20 rabbits were investigated. High-dose radioiodine therapy applying 1 GBq (131)I was performed in 16 animals. Eight of these 16 animals received 200 mg/m(2) body surface amifostine prior to high-dose radioiodine therapy. Four additional rabbits served as controls, two receiving amifostine, the other two no treatment at all. Subsequently, salivary glands (submandibular and parotid glands, respectively) of all animals were examined by light and transmission electron microscopy. RESULTS: Parenchymal damage of both parotid and submandibular glands, specially acinar structures comprising cell organelles and nuclei, of animals pretreated with amifostine was much less pronounced than in animals without amifostine pretreatment. CONCLUSION: The results indicate that parenchymal damage in salivary glands induced by high-dose radioiodine therapy can significantly be reduced by amifostine. Therefore, amifostine therapy may increase quality of life in patients with differentiated thyroid cancer after radioiodine treatment.     

Prediction of absorbed dose to normal organs in thyroid cancer patients treated with 131I by use of 124I PET and 3-dimensional internal dosimetry software.

The objective of this work was to determine normal organ (131)I dosimetry in patients undergoing radioiodide therapy for thyroid cancer by use of serial scanning with (124)I PET. METHODS: A total of 26 patients who had papillary and follicular metastatic thyroid cancer and who were already enrolled in a Memorial Sloan-Kettering Cancer Center (131)I thyroid cancer protocol were selected for this study. Imaging before (131)I therapy consisted of multiple, whole-body (124)I PET studies over a period of 2-8 d, an (18)F-FDG PET scan and, for some, a diagnostic CT scan. With a set of in-house-developed software tools (3-dimensional internal dosimetry [3D-ID] and Multiple Image Analysis Utility [MIAU]), the following procedures were performed: all PET emission and transmission and CT image sets were aligned; half-life-corrected tomographic images of (131)I activity were integrated voxel by voxel to produce cumulated (131)I activity images; and the latter images were, in turn, convolved with a (131)I electron-photon point kernel to produce images of (131)I dose distribution. Cumulated activity values and calculated residence times obtained from our patient-specific dosimetry software (3D-ID) were used as inputs to OLINDA, and volume difference-adjusted comparisons were made between the mean dose estimates. RESULTS: With 3D-ID, dose volume histograms and mean doses were calculated for 14 organs, and results were expressed in Gy/GBq. The highest mean dose, 0.26 Gy/GBq, was seen in the right submandibular gland, whereas the lowest mean dose, 0.029 Gy/GBq, was seen in the brain. CONCLUSION: This is the first comprehensive study of normal organ dosimetry in patients by use of a quantitative tomographic imaging modality.     

颌下腺混合瘤的CT表现

目的：总结分析颌下腺混合瘤的CT表现。方法：回顾性分析13例经手术病理证实的颌下腺混合瘤的CT表现,所有病例均行轴面平扫和增强扫描,并与病理结果进行对比分析。结果：所有病例均为单侧单发病灶。平扫7例密度低于正常腺体,4例呈等密度,2例密度不均匀,病灶与正常腺体分界不清,13例患侧腺体均增大,肿瘤均未突出腺体包膜,与周围组织的脂肪间隙仍存在;增强扫描病灶强化程度均低于正常腺体,表现为轻至中度强化,3例病灶内出现大小不等圆形低密度影。病灶直径1.4-3.2 cm。结论：颌下腺混合瘤CT表现具有良性肿瘤的特点,结合临床病史,CT可做出正确诊断。     

High Prevalence of Thyroid Disease and Role of Salivary Gland Scintigraphy in Patients with Xerostomia

Purpose

Although Sjögren’s syndrome (SS) is the most common disease causing xerostomia, autoimmune thyroid diseases can also affect the salivary glands. The aim of our study was to estimate the prevalence of thyroid diseases (TD) in subjects with symptoms of xerostomia and evaluate the efficacy of salivary gland scintigraphy (SGS) in the detection of TD in patients with SS and without SS.

Methods

We retrospectively reviewed the SGS findings of 173 subjects (men:women, 29:144) with symptoms of xerostomia. Ejection fractions (EF) in the parotid and submandibular glands were calculated. Thyroid disease was diagnosed on the basis of the results of the visual assessment of tracer uptake in the thyroid gland on SGS images as well as serological thyroid function tests.

Results

Based on the American-European Criteria, 94 patients were diagnosed with SS. Hashimoto’s thyroiditis was diagnosed in 63 patients, subacute thyroiditis in 23, subclinical hypothyroidism in five, and Graves’ disease in one. There were significant differences in the EF values of the parotid and submandibular glands between patients with TD and those with undetermined diagnoses.

Conclusions

More than half of patients with xerostomia exhibited TD. Thyroid assessment by SGS is feasible, and SGS appears to be useful for the patients with xerostomia caused by TD. SGS may be the first imaging modality capable of evaluating both salivary gland function and thyroid gland status in patients with xerostomia. This strategy would make the requirement for additional workup for thyroid disease.

     

Age-dependent decrease in the computed tomographic numbers of parotid and submandibular salivary glands

The computed tomographic (CT) numbers of 182 normal parotid glands were measured in patients ranging in age from 1 to 81 years, and of 172 normal submandibular glands with an age range of 1-85 years. The mean CT number (+/- s.d.) of the parotid and the submandibular glands was -10 +/- 24 Hounsfield units (HU) and 41 +/- is HU respectively. Sex and intra-individual differences in the CT numbers were small, but significant linear decreases were found with age in both glands. The mean annual decrease was 0.5 HU.     

Correlation between quantitative salivary gland scintigraphy and salivary secretion rates in children and young adults treated for hematological, malignant and metabolic diseases

OBJECTIVES: To study the correlation between whole salivary secretion rates and different variables from the radionuclide time-activity curve and to determine a reliable region for background correction in salivary gland scintigraphy. METHODS: Salivary gland scintigraphy (SGS) was performed before bone marrow transplantation or more than 4 years later in 23 patients aged 13.5 (s.d. 4.9) years. Unstimulated and stimulated whole salivary secretion rates were measured before SGS. Six different methods for background correction were evaluated. RESULTS: The unstimulated secretion rate was significantly correlated (P < 0.05) with the percentage stimulated secretion (S) and reaccumulation-slope (RS) after stimulation. The stimulated secretion rate was significantly correlated with RS, S and down-slope (DS). The temporal region above the parotid glands and the area above the thyroid gland was used for subtraction of background radiation for the parotid and submandibular glands respectively showed a strong correlation between repeated measurements of the variables analysed. The mean maximum uptake was 0.73-1.34% of total dose injected. CONCLUSIONS: The salivary scintigraphic variables which correlated more strongly with salivary secretion rates were RS, S and DS. The temporal region above the parotid gland and the area above the thyroid gland can be used reliably for correction background radiation in the analysis of the time-activity curve in SGS of the parotid and submandibular glands respectively.     

Carcinosarcoma of the salivary gland on CT.

Three cases of carcinosarcoma of the salivary gland, two in the submandibular gland, and one in the parotid, were investigated with CT and exhibited a variety of findings. The density of the tumors was lower than that of normal submandibular tissue. A calcification was found in one case. One case showed extensive lymphadenopathy. The parotid lesion had low central density with an enhancing margin.     

正常人下颌下腺的多层螺旋CT影像解剖研究

目的 研究正常人下颌下腺的多层螺旋CT(MSCT)影像解剖,为临床判断有无异常提供依据.资料与方法 选择无颈部疾病和无下颌下腺疾病、无阻塞性睡眠呼吸暂停综合征(OSAS)的健康自愿者100名(男女各50名),对下颌下腺进行MSCT扫描,应用图像后处理工作站的多平面重组(MPR)软件测量下颌下腺轴位最大截面积及左右径的大小;冠状位最大截面积及上下径的大小;矢状位最大截面积及前后径的大小;测量左右两腺体间的最近距离(腺间距)、两侧下颌下腺后缘连线与颈椎前缘的距离(腺-椎间距)并检测腺体CT值,用SPSS l0.0统计分析软件包行统计学分析.结果 冠状位和矢状位最大截面积及最大径线男女间差异有统计学意义.腺-椎间距男女差异无统计学意义;腺间距男女差异有统计学意义.儿童上下径线和腺间距小于成人.CT值同体形者男性高于女性,儿童高于成人.结论 应用MSCT扫描和图像后处理技术测量下颌下腺各截面积及各径线长度简单、廉价、易行,是对头颈部影像学研究、测量的重要补充.     

Quantitative aspects of pertechnetate concentration in human parotid and submandibular salivary glands..

Quantitative uptakes of 99Tcm-pertechnetate by the salivary glands have been measured in 36 subjects and normal values established. While uptake over the parotid gland increased with time, parotid uptakes were higher at all time intervals than uptakes over the submandibular glands. The uptake over the submandibulars also increased with time. There was no significant difference between resting uptakes of right and left glands, a significant difference would therefore suggest the presence of pathology. Values over the parotid gland are greater under resting conditions than following stimulation, but no such difference was noted for submandibular glands. However, with stimulated glands it was also shown that there was no significant difference between the right and left parotid, or rignt and left submandibular uptakes. The clinical relevance of these findings is discussed.