Somatic mosaicism of p(CTG)n expansion in a case of myotonic dystrophy with parotid tumor

Myotonic dystrophy (MD) is an autosomal dominant systemic disorder with an unstable expansion of the CTG triplet repeat in the 3'-untranslated region of the gene encoding myotonine protein kinase (DMPK) which maps to chromosome 19q13.3. Somatic mosaicism of CTG repeats in MD has been reported; and it has been observed that CTG repeats in tumor tissues associated with MD are more expanded than the other tissues. It is not rare that parotid tumors are found in patients with MD. We performed Southern blot analysis for tissues from the parotid tumor, the normal parotid gland, the skeletal muscles, and the leukocyte from a 60-year-old patient with MD. CTG repeat was most expanded in the parotid tumor, and the normal parotid gland had longer expansion of CTG repeat than the skeletal muscles. The leukocyte had the shortest expansion of CTG repeat. The expansion of CTG repeat in the parotid tumor may be related to active cell division and may underlie the occurrence of tumors in MD.     

Video-assisted thoracoscopic surgery for spontaneous hemopneumothorax

PURPOSE: This study examined the usefulness of magnetic resonance imaging (MRI) in assessing whether parotid tumors were located in the superficial or deep lobe. PATIENTS AND METHODS: Eight patients with parotid gland tumors underwent MRI using a spin echo pulse sequence. T1- and T2-weighted images were obtained. To assess tumor localization in the parotid gland, two anatomic landmarks were used: 1) a line connecting the lateral surface of posterior belly of digastric muscle and lateral surface of the cortical bone of ascending ramus (facial nerve [FN] line) and 2) the relationship to the retromandibular vein (RV). Results of all MRI examinations were compared with the surgical findings. RESULTS: Seven of eight cases were correctly diagnosed using the FN line criterion. Five of eight cases were correctly diagnosed using the RV criterion. CONCLUSION: MRI is an excellent modality to show tumor localization in the parotid gland.     

Identification of marker chromosomes and translocations in man using a computerized diagnostic database and fluorescent in situ hybridization

BACKGROUND: Many species of bats have two sets of submandibular glands, principal and accessory. The accessory gland may resemble the principal one but more often shows wide morphological divergence. The free-tailed bat, Tadarida thersites, is very unusual in that it has two sets of parotid glands rather than binary submandibular glands. We studied the ultrastructure of the principal parotid gland to establish a baseline for comparison with the accessory parotid. METHODS: Two specimens of adult free-tailed bats, one male and one female, were live-trapped in western Kenya. Parotid glands were fixed for electron microscopy using a protocol expressly designed for field fixation and then embedded by conventional means. RESULTS: Histologically, the principal parotid is a typical serous gland. The secretory granules of the endpiece cells have an unusual substructure in that they contain variable numbers of lucent halos and one or several spherules. Intercalated duct cells contain a significant number of dense, serous-like granules. Striated ducts have the usual basal configuration of mitochondria and folded plasma membranes, but the supranuclear cytoplasm contains many small, dense granules, so that these ducts resemble the granular convoluted tubules found in the submandibular glands of many families of rodents. The apices of the duct cells have a peculiar contour--the luminal surfaces obliquely invaginate into the apical cytoplasm, so that in thin section the luminal membranes appear to be underlaid by a layer of vacuoles. CONCLUSION: Although the principal parotid gland of the free-tailed bat shows some distinctive, species-specific ultrastructural features, it basically is similar to the parotid gland in two other molossid bats, Tadarida brasiliensis and Molossus molossus. The distinctive features in the principal parotid gland of T. thersites might relate to its feeding on hard-bodied insects and perhaps to the production of lysozyme.     

A severe form of Sjogren's syndrome

Sjogren's syndrome is an autoimmune disease characterized by exocrine gland destruction and manifested by parotid, submandibular and lacrimal gland infection. We report a case with recurrent severe parotid gland infections. The sialographic and CT findings are presented.     

Irradiation-induced damage to the salivary glands: the role of redox-active iron and copper

The mechanism of irradiation-induced hypofunction of the salivary glands is a process that is not fully understood. Here we examine the hypothesis that intracellular and redox-active ions of iron and copper, which are associated with the secretion granules, play a catalytic role in the irradiation-induced damage. Rats were subjected to head and neck irradiation (15 Gy X rays) and allowed to recover for 2 months. The function of the parotid and submandibular glands was then determined by pilocarpine-stimulated salivary secretion. A 45% decrease in the function of both glands was obtained when compared to nonirradiated controls. Treatment prior to irradiation (90 min) with cyclocytidine (200 mg/kg) led to a massive degranulation of the parotid gland and yielded nearly complete protection from radiation-induced damage. In contrast, pilocarpine stimulation prior to irradiation led to a marginal degranulation of the parotid gland and yielded only 13% protection. Neither agent caused degranulation of the submandibular gland mucous cells or yielded functional protection of this gland. Treatment with both agents yielded a marked increase in iron, copper and manganese levels in the parotid gland saliva. An analogous marked increase in the redox activity of iron and copper ions was recorded for the parotid saliva stimulated by pilocarpine and cyclocytidine. Pilocarpine-stimulated submandibular gland saliva contained metal levels similar to those of the parotid gland saliva. However, no redox activity and no increase in metal mobilization could be demonstrated in the submandibular gland saliva stimulated by both agents. The correlation between the patterns of gland degranulation, mobilization of redoxactive metals and the protection of gland function, for both parotid and submandibular glands, focuses attention on the catalytic roles played by transition metal ions in promoting free radical reactions, which likely participate in the process of injury to the tissue.     

Mucoepidermoid carcinoma of the parotid gland: a rare presentation in a young child

Although mucoepidermoid carcinoma (MEC) is the most common malignant salivary gland neoplasm in childhood and adolescence, it is rarely found in children under the age of 10. A 6-year-old girl had an asymptomatic neck mass for 5 months. Clinical examination findings showed a 1.5-cm smooth and firm but mobile nontender mass located in the upper left anterior cervical triangle, clinically separate from the parotid gland. Ultrasound examination findings showed a vascular mass, with a cystic component, possibly within the tail of the parotid gland. An excisional biopsy was performed and frozen section showed a low-grade MEC. A left superficial parotidectomy was then performed. Final histopathologic examination showed one positive resection margin. Subsequently, reexcision of the surgical site and an upper modified neck dissection was undertaken. This unusual presentation of MEC as a neck mass in one of the youngest reported patients illustrates that the anatomic region for parotid tumors is large. Possibly some of these tumors may arise from heterotopic or accessory parotid tissue.     

Direct activation of K(Ca) channel in airway smooth muscle by nitric oxide: involvement of a nitrothiosylation mechanism?

The rat parotid gland produces a number of well-characterized secretory proteins. Relatively little is known, however, about the onset of their synthesis and cellular localization during gland development. Secretory protein expression was studied in parotid glands of fetal and postnatal rats using light and electron microscopic immunocytochemistry and Northern blotting. Amylase, parotid secretory protein (PSP), common salivary protein-1 (CSP-1), and SMGB were first detected by immunofluorescence in parotid glands of 18 day fetuses. By 5 days after birth, light and electron microscopic immunolabeling localized all of these proteins to the secretory granules of developing acinar cells. Labeling of acinar cells for DNAse I, however, was not observed until 18 days after birth. Between 9 and 25 days, CSP-1 and SMGB reactivity of acinar cells declined, but increased in intercalated duct cells. After 25 days, CSP-1 and SMGB were found only in intercalated ducts, and amylase, PSP, and DNAse I were restricted to acinar cells. Levels of CSP-1 and SMGB mRNA were relatively constant through 21 postnatal days, but declined significantly after that. Amylase and PSP mRNA increased rapidly and continuously from five days after birth to the adult stage. In contrast, DNAse I mRNA was not detectable until 18 days after birth. The immunocytochemical and molecular analyses define three basic patterns of protein expression in the rat parotid gland: proteins whose synthesis is initiated early in development and is maintained in the acinar cells, such as amylase and PSP; proteins that are initially synthesized by immature acinar cells but are restricted to intercalated ducts in the adult gland, such as CSP-1 and SMGB; and proteins that are synthesized only by mature acinar cells and first appear during the third postnatal week, such as DNAse I. The parotid gland exhibits four distinct developmental stages: prenatal, from initiation of the gland rudiment until birth; neonatal, from 1 day up to about 9 days postnatal; transitional, from 9 days to 25 days of age; and adult, from 25 days on. Although differences exist in timing and in the specific proteins expressed, these developmental stages are similar to those seen in the rat submandibular gland. Additionally, the results support the suggestion that intercalated ducts may differentiate from the neonatal acini.     

Neuroblastoma of parotid gland: report of a case and immunohistochemical characteristics

A case of a parotid mass in a 2-year-old boy, postoperatively diagnosed as neuroblastoma, a rare tumour not previously reported in the parotid gland is presented. The neoplasm developed within the parotid gland as a painless mass without regional lymphadenopathy. Histopathologically, the tumour showed primitive nerve cells-neuroblasts-with round or oval dark basophilic nuclei and scanty cytoplasm. The cells were arranged in circular rosettes around an eosinophilic mass consisting of very fine filaments originating in the tumour cells or papillary configuration and sometimes scattered in the poorly developed stroma. Immunohistochemical evaluation of the tumour showed a positive immunoreactivity for vimentin, alpha and beta subunits of S-100 protein, neurone-specific enolase (NSE), substance P, met-enkephalin and chromogranin but cytokeratins, desmin, actin, myosin, glial fibrillary acidic protein (GFAP) and calcitonin gene related peptide (CGRP) were negative. The histopathological and immunohistochemical findings conclude a diagnosis of neuroblastoma of the parotid gland.     

Elevated serum levels of cyclo (His-Pro), an endogenous inhibitor of pituitary prolactin secretion, in systemic lupus erythematosus patients

We sought to determine whether an increased frequency of the HLA-DR11 (formerly DR5) phenotype is found in human immunodeficiency virus (HIV)-infected children with parotid gland enlargement. In HIV-infected adults, parotid gland enlargement may be part of the diffuse infiltrative CD8 lymphocytosis syndrome. An increased frequency of expression of HLA-DR11 has been described in association with diffuse infiltrative CD8 lymphocytosis syndrome. We conducted a case-control study with 26 HIV-infected children, 13 of whom had parotid gland enlargement and 13 of whom did not but who were matched for age, race, and sex with those with parotid gland enlargement. Clinical and laboratory parameters (including HLA-DR11 phenotype) were compared between the two groups. HIV-positive children with parotid gland enlargement showed an increased frequency of HLA-DR11, similar to their adult counterparts with diffuse infiltrative CD8 lymphocytosis syndrome. The HLA-DR11 phenotype may be associated with the development of parotid gland enlargement in HIV-infected children and may be a marker for a more benign outcome of HIV infection.     

Effect of variation in dietary NaCl intake on total and fractional renal blood flow in the normal and mercury-intoxicated rat

The influence of parasympathetic and sympathetic nerves on the parotid gland of the rat was investigated. It was found that both divisions of the autonomic nerves evoke secretion and probably also motor effects in this gland. Secretion elicited on sympathetic stimulation was mediated both via alpha- and beta-adrenoceptors, while motor effects were mediated via alpha-adrenoceptors. On stimulation of the autonomic nerves a lower duct pressure was reached in the parotid than in the submaxillary gland, and on sympathetic nerve stimulation the flow of saliva always started later from the parotid than the submaxillary gland. These findings are discussed in the view of the different arrangement of the myoepithelial cells in the 2 glands.     

Salivary duct carcinoma: a clinicopathologic study of three cases with a review of the literature

Three cases of salivary duct carcinoma are presented. They occurred in a 60 year old man, a 66 year old man and a 57 year old woman. All of the lesions were located in the parotid gland. The tumor size ranged from 3 to 5 cm across the largest diameter. Facial paralysis was observed in two cases. Histologically, intraductal and invasive adenocarcinoma showing papillary, cribriform, and solid patterns with comedolike necrosis was observed. Immunohistochemically, the tumor cells were positive for keratin and epithelial membrane antigen. No myoepithelial cells were demonstrated within the tumor by staining for S-100 protein, alpha-smooth muscle actin or muscle specific actin. Ultrastructurally, intracytoplasmic lumina with microvilli, a moderate number of mitochrondria, lysosomes, and tight junctions were found. Regional lymph node metastasis was observed in one case, and distant metastasis developed in two cases. All of the patients were treated with adjuvant postoperative irradiation. One patient died of disease at 11 months after the initial diagnosis, another was alive with disease at 8 months, and the third patient was alive without disease at 2 years and 3 months. Salivary duct carcinoma should be differentiated from low-grade salivary gland carcinomas using morphologic and clinical criteria because of its poor prognosis even with aggressive therapy.     

Haemangiopericytoma of the parotid salivary gland: report of a case with literature review

Haemangiopericytoma is a rare, soft tissue, tumour with unpredictable biological behaviour. A case of haemangiopericytoma of the parotid salivary gland is reported. The clinical, surgical and histological features are described.     

Lipoma of the superficial lobe of the parotid gland. A case report

We report the case of a patient with a lipoma of the superficial lobe of the right parotid gland. Lipomas of the parotid gland are very rare. They are said to constitute one to two percent of all parotid tumours. Only six cases were found in the recent literature. Preoperative diagnosis is difficult when the physical examination reveals a renitent, well-localized and painless mass. However, magnetic resonance imaging is now the imaging modality of choice to facilitate the diagnosis, but the diagnosis can only be confirmed by histological examination of the tumour. We discuss the value of superficial parotidectomy, while some authors suggest an enucleation of lipomas of the superficial lobe of parotid.     

In defense of a body mass index of 25 as the cut-off point for defining overweight

A dermoid cyst occurring within the parotid gland of a 37-year-old Chinese man is reported. The diagnostic difficulties, histopathological features and pathogenesis are considered.     

Myelodysplastic transformation in a case of essential thrombocythemia treated with pipobroman

A report of an 87-year-old Caucasian female with an extensive sebaceous carcinoma of the parotid gland is presented. The computed tomographic characteristics of this rare neoplasm are reported for the first time.     

Ophthalmic findings with partial trisomy (duplication) of the long arm of chromosome 7

BACKGROUND: The sensitivity of diagnostic imaging of processes in the parotid gland has been increased by improved spatial resolution, yet specificity remains unchanged. The purpose of this study was to determine whether the low-flow color duplex technique alters the specificity of B-mode ultrasonography. PATIENTS AND METHODS: Forty-one patients with tumors of the parotid gland were examined by color duplex echography as well as histologically. Twenty-eight of the 41 patients had benign tumors and 13 had malignant disease. In 17 of 41 patients, color duplex ultrasonography failed to detect any vascularization within the tumor. Histopathological examination showed that 3 of these 17 tumors were malignant and 14 of 17 were benign. Intranodal vascularization was detected in 24 cases. Ten of these patients were found to have malignant tumors of the parotid gland; 14 had benign parotid tumors. RESULTS: Our present findings show that marked intratumoral vascularization especially appears in malignant tumors. In contrast to lymph nodes, the location and texture of intranodal blood vessels do not provide information about the nature of the neoplasm. CONCLUSIONS: Low flow duplex ultrasonography does not increase the specificity of preoperative examination in tumors of the parotid gland.     

The use of the SMAS to close Mohs defects invading the parotid gland

BACKGROUND: Plastic surgery literature reports the use of the superficial musculoaponeurotic system (SMAS) in reconstruction after parotidectomies to prevent the complications of Frey's Syndrome and fistula formation. However, there is scant information in the dermatologic literature regarding the use of the SMAS when closing Mohs defects overlying the parotid gland. OBJECTIVE: Our purpose is to introduce to the dermatologic surgery literature the need for plication of the SMAS prior to closure of the overlying tissues when repairing surgical defects which invade the integrity of the parotid gland. METHODS: We describe a patient with a large basal cell carcinoma located in the right preauricular region. Using text and photographs, we detail our closure of this large defect which invaded the parotid gland. RESULTS: Closure of the SMAS over the parotid gland before suturing the overlying tissues provided our patient with an excellent functional and cosmetic result, without the formation of a fistula, sialocele, or Frey's Syndrome. CONCLUSION: We propose that the essential first step in the ideal closure of surgical wounds which penetrate the parotid gland involves the isolation and plication of the SMAS. This will create a barrier to the accumulation of parotid secretions which, in turn, may lead to the development of a sialocele and fistula formation. Such a barrier will also prevent the formation of Frey's Syndrome. Furthermore, plication of the SMAS serves to improve cosmesis by contributing soft tissue bulk to the wound and avoiding a concave deformity.     

Observations on two cases of apparent submandibular gland cysts in HIV positive patients: MR and CT findings

OBJECTIVE: To present two cases of probable lymphoepithelial cysts of the submandibular glands in patients who were human immunodeficiency virus (HIV) positive and who also had lymphoepithelial cysts of the parotid glands. MATERIALS AND METHODS: Computed tomography and MRI of two HIV positive patients with lymphoepithelial cysts of the parotid glands and cysts in the submandibular glands were correlated with the histories and the possible presence of other known causes of submandibular gland multiple cysts. RESULTS: Because of the present treatment philosophy regarding HIV positive patients with major salivary gland cysts, surgical resection of these glands was not performed. All other known causes of multiple submandibular gland cysts were excluded by either history or laboratory data. CONCLUSION: Computed tomography and MRI on two patients with known HIV infection and bilateral parotid lymphoepithelial cysts are presented. Both patients also had bilateral multiple submandibular gland cysts and no evidence of obstructive glandular disease, autoimmune disease, or other organ system cysts. These cases of presumed submandibular gland lymphoepithelial cysts are rare in the literature. They are presented in the hope that other radiologists will be stimulated to document the occurrence of this entity.     

Child psychiatric consultation service to community agencies: a collaborative approach involving three community agencies

A patient with malignant mixed tumor of the parotid gland with myoepithelial carcinomatous and papillary cyst adenocarcinomatous components is presented. Clinically the patient had a giant mass in the parotid location for 20 years, with a growth progression during the last 6 months. The undefined connection of two carcinomatous components of malignant mixed tumor is reviewed.     

The effect of local radiotherapy on kallikrein activity in saliva secreted by parotid gland in patients with head and neck cancers

The samples of parotid gland saliva, collected from control human subjects and those taken from patients with head and neck cancers were submitted to the assay of protein concentration and kininogenase and amidolytic kallikrein activities. No patients with parotid gland tumours were included. The effect of pilocarpine stimulation on these parameters was studied. It was found that the saliva secreted by parotid gland of the investigated patients contains less protein and lower kininogenase activity in comparison to control subjects. Pilocarpine administration resulted in an increase of protein concentration and a decrease of kallikrein activity both in control and investigated subjects. Radiotherapy did not evoke any significant changes in spontaneously secreted saliva. The radiotherapy resulted in a progressive decrease of protein concentration and kallikrein activity in saliva secreted by pilocarpine stimulated glands. The kallikrein activity per mg of protein contained in spontaneously secreted saliva increased significantly during radiotherapy but it distinctly decreased in the saliva of pilocarpine-treated patients. It allows to conclude that the parotid glands do not lose their ability to synthesize and secrete kallikrein during radiotherapy of head and neck cancers.