Tuberculosis of the parotid gland

The presentation of tuberculosis as an isolated parotid lump is rare. In this paper, six cases with tuberculous parotitis are reported which were evaluated as a benign parotid neoplasm in 216 specimens pre-operatively. All but one of them had no previous history of tuberculosis and all had a parotid lump as a sole symptom for at least one year. The diagnosis of tuberculosis was made, after superficial parotidectomy, by histopathology. Parenchymal involvement and intraparotid lymph node involvement with tuberculosis were seen in five and three patients, respectively. Two of the patients had lymph node involvement outside the parotid area. One of six patients had a coincidental Warthin tumour. A surgical approach is not only therapeutic but also diagnostic when other diagnostic tools fail.     

Tumors of the parotid gland

Tumors of the parotid are the most frequently encountered salivary gland tumors. Knowledge of the histology and anatomy of the salivary gland is important when considering the histiogenesis of salivary gland tumors, requiring close cooperation between the pathologist and the surgeon. Most tumors are benign epithelial formations. Pleomorphous adenomas predominate. Superficial lobectomy is adequate treatment. When the tumor involves a deep lobe, total parotidectomy is indicated. Treatment of malignant tumors depends on the histology, its TNM stage and other factors. Total parotidectomy with lymphadectomy and radiotherapy are needed in case of high grade malignancy. In children, vascular neoplasias are the most frequent, followed by malignant tumors. Their histological features and treatment are the same as for adults.     

Epithelial-myoepithelial carcinoma of the parotid gland

We sought to determine if patients with cystic fibrosis and sputum cultures positive for Mycobacterium avium complex (MAC) have delayed-type hypersensitivity to an M. avium sensitin. Seventeen (33%) of 51 selected patients had MAC isolated from at least one sputum culture. Skin tests with purified protein derivative and M. avium sensitin demonstrated that five (10%) of 51 patients were anergic, and anergy was correlated with use of systemic steroids. Sixteen (35%) of 46 nonanergic patients had M. avium-dominant skin test reactions. Twelve (75%) of these 16 patients with cultures positive for MAC had M. avium-dominant skin tests; the specificity of skin testing was 87%. These data suggest that most patients with cystic fibrosis and sputum cultures positive for MAC have infection rather than colonization with MAC. Skin testing with M. avium sensitin is a sensitive and specific method for screening these infections.     

A megalith of the parotid salivary gland

We present a rare case of a giant intra-parotid calculus in a 64-year-old man with recurrent parotitis. The literature is also reviewed.     

The ultrastructure of the sheep parotid gland

The sheep parotid is a compound tubular gland; its ultrastructure reflects the function of this gland to secrete large amounts of fluid with very little protein. The cells of the secretory tubules possess extensively folded lateral plasma membranes and a fairly large number of mitochondria. Rapid equilibration of water across the epithelium is assured by the close proximity over large areas of intercellular spaces and the wide secretion canaliculi. Numerous long microvilli extend into the latter. Although secretion granules may be quite numerous, there is evidence that many of these granules are not discharged but undergo degradation by lysosomal enzymes. The intercalated ducts are often dilated but excessive distension is probably prevented by bundles of microfilaments in their epithelial cells.     

Selective incorporation of architectural proteins into terminally differentiated molluscan gill cilia

Incubation of excised gills from the bay scallop Aequipecten irradians with 3H-leucine demonstrates that many ciliary structural proteins can attain a degree of labeling approaching that previously reported for sea urchin or surf clam embryos undergoing ciliary turnover or regeneration. This labeling is not a consequence of any predominant incorporation into new cilia at the meristematic growth tips of the gill since tissue regions of varying maturity incorporate label into the same proteins at similar levels, with the most mature region having the highest incorporation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and fluorographic analysis of isolated cilia, separated into detergent-soluble membrane/matrix and detergent-insoluble 9+2 axoneme fractions, reveals that 1) tubulin in the membrane/matrix fraction is labeled whereas tubulin in the axoneme is not; 2) no labeled dynein heavy chains are seen in either fraction; 3) the most heavily labeled axonemal components do not appear to any significant extent in the membrane/matrix fraction; and 4) after thermal depolymerization of the microtubules, nearly all labeled proteins reside in the in-soluble ninefold ciliary remnant, the most prominent being tektin A, an integral component of outer doublet microtubules. Further fractionation of the remnant with sarkosyl-urea to produce tektin filaments demonstrates two solubility classes of tekin A, only the more soluble of which is labeled. Very similar selective architectural protein labeling patterns have been reported for steady-state cilia of sea urchin embryos, and this may indicate a widespread turnover or exchange mechanism characteristic of cilia heretofore considered static.     

The case of myoepithelioma of the parotid gland

STUDY OBJECTIVE: To determine whether the environment of a moving ambulance affects the ability of our-of-hospital care providers to auscultate breath sounds. METHODS: Out-of-hospital care providers assessed breath sounds with a previously described breath-sounds model in a quiet environment (control) and in a moving ambulance. The setting was a nonurban emergency medical services system and an interhospital transport agency based at a 600-plus-bed tertiary care center. The participants were physicians, transport nurses, and advanced life support EMS providers routinely involved in the emergency out-of-hospital treatment and transportation of the ill and injured. The accuracy with which participants identified the presence or absence of breath sounds in the two environments was compared with the use of the chi 2 test, with the alpha-value set at .05. RESULTS: The accuracy of breath-sounds assessment in the control environment was 96% (251 of 260); the sensitivity was 96% and the specificity 97%. The accuracy of breath-sounds assessment in the experimental environment was 54% (140 of 260); the sensitivity was .09% and the specificity 98%. Participants were significantly less likely to hear breath sounds in the moving ambulance than in the quiet room (P < .001). CONCLUSION: Assessment of breath sounds is hampered by the environment of a moving ambulance.     

In vivo incorporation of ribosomal proteins into HeLa cell ribosomal particles

Using high salt-washed ribosomal subunits from HeLa cells we detect three ribosomal proteins from the small subunit and five ribosomal proteins from the large subunit that enter ribosomal particles in the absence of ribosome formation (actinomycin D-treated cells); in untreated cells, they enter the ribosomal particles quickly, while the rest of the ribosomal proteins are incorporated gradually. At least two of the large subunit actinomycin D-resistant ribosomal proteins seem to be absent in the 55 S nucleolar ribosomal precursor.     

Polymorphous low-grade adenocarcinoma of the parotid salivary gland

Polymorphous low-grade adenocarcinoma is an unusual tumor that has been described as occurring in the minor salivary glands, particularly of the palate. To our knowledge, there is only one previous report that has documented the occurrence of this type of lesion in the major salivary glands. We describe an elderly patient with polymorphous low-grade adenocarcinoma arising in the parotid gland that was originally diagnosed as carcinoma ex pleomorphic adenoma.     

Surgical pathology of parotid gland tumors

The records of 27 patients operated for parotid tumors were reviewed retrospectively. Pleomorphic adenoma was the most frequent tumor (37.1%) and required subtotal parotidectomy in all cases. Twenty percent presented permanent facial paralysis of the marginal mandibular branch. No recurrence has been observed in five years of follow-up. Warthin's tumor, found in 11.1% of patients, was removed by either superficial or subtotal parotidectomy. Parotidean cysts were observed in 7.4% and were excised by superficial parotidectomy. The malignant tumors included squamous cell carcinoma (22.2%), adenoid cystic carcinoma (14.8%), melanoma (3.7%), and renal-cell metastasis (3.7%). All were treated by total parotidectomy with conservation of the facial nerve in 67%. Twenty-five percent had postoperative facial paralysis and 33% developed Frey's syndrome. Thirty-three percent died in the next 5 years from locoregional metastases.     

Study of malignant lymphoma in the parotid gland region

Malignant lymphomas arising in the salivary glands are very uncommon. The vast majority of these lesions are classified as extranodal non-Hodgkin's lymphoma. Clinical presentation, management, histopathology, and outcome in 11 cases of non-Hodgkin's lymphomas of the parotid gland region were reviewed. The ages of the patients ranged from 25 to 80 years (average 56.0 years) and the male to female ratio was 5:6. Presenting symptoms were painless masses (10 cases) and a painful mass (1 case) in the parotid gland region. None of the patients had facial nerve paralysis. It seems to be difficult to diagnose malignant lymphomas of the salivary glands preoperatively, because an open biopsy of the salivary glands is generally contraindicated. We failed to diagnose malignant lymphoma in the parotid gland preoperatively. The clinical stages were stage I in 5 cases, stage II in 5 cases, and stage III in 1 case. There was no patient with stage IV. Three of the stage I tumors were diagnosed as MALT (mucosa-associated lymphoid tissue) lymphomas. Eight of the tumors were treated surgically and an open biopsy of the parotid gland tumor was performed in 1 case and open biopsy of a neck lymph node in 2 cases for the purpose of diagnosis. After the diagnosis, these cases were followed up with or without radiotherapy and chemotherapy. Follow-up ranged from 6 to 109 months. The 5-year-survival rate was 60%. The outcome for this group was found to be as good as that reported by others.     

Distribution of radioactivity in the body and rate of incorporation of radioactivity into the tissue proteins of monogastric animals following intravenous injection of tracer amino acids

The studies were carried out with pigs and rats. The radioactive animo acids (14C leucine and 3H lysine) were administered to the pigs by way of a catheter tube into the jugular vein. Subsequently, the time pattern of the distribution of the specific amino acid radioactivity was followed in the TCE soluble and Tce precipitable fractions of the blood plasma (TCE= trichloro-acetic acid). The radioactive labelling in rats was carried out by injecting 14C leucine into the portal vein. The animals were killed after incorporation periods from 2 to 60 mins, and the levels of specific radioactivity were estimated in the TCE soluble and TCE precipitable fractions of the blood plasma, in the liver and in the skeletal muscles. The experimental results clearly indicated that the specific radioactivity of the tracer amino acids and the rate of incorporation of radioactivity into tissue proteins were greatly influenced by the size of the free amino acid pool within the range of distribution of the tracer. An estimation of the magnitude of the pool of free amino acids within the distribution range of the tracer can be obtained from the curve pattern for the decline of specific radioactivity of the corresponding free amino acid in the blood plasma. This pool exhibits a high rate of turnover. In all studies made to evaluate in vivo processes of protein synthesis by use of radioactive tracer amino acids it will be particularly important that consideration should be given to the specific radioactivity of the amino acid in the precursor pool for protein synthesis.     

In vitro incorporation of GPI-anchored proteins into human erythrocytes and their fate in the membrane

In many different cells, glycosylphosphatidylinositol (GPI)-anchored molecules are clustered in membrane microdomains that resist extraction by detergents at 4 degrees C. In this report, we identified the presence of such domains in human erythrocytes and examined the ability of exogenously-added GPI-anchored molecules to colocalize with the endogenous GPI-anchored proteins in these detergent-insoluble complexes. We found that the addition to human erythrocytes of three purified GPI-anchored proteins having different GPI lipid moieties resulted in their efficient and correct incorporation into the membrane. The extent of membrane insertion was dependent on the intactness of the GPI lipid moiety. However, unlike the endogenous GPI-anchored proteins, the in vitro incorporated GPI molecules were not resistant to membrane extraction by Triton X-100 at 4 degrees C. In addition, in contrast to the endogenous GPI-anchored proteins, they were not preferentially released from erythrocytes during vesiculation induced by calcium loading of the cells. These results suggest that in vitro incorporated GPI-linked molecules are excluded from pre-existing GPI-enriched membrane areas in human erythrocytes and that these microdomains may represent the sites of membrane vesicle formation.     

Ultrasonographic diagnosis of the parotid gland tumors--experience with 310 patients

The diagnostic value of ultrasonography of parotid gland tumors is to determine if the tumor is benign or malignant. In the period from 1984 to 1995, ultrasound examinations were performed on 310 patients with a space-occupying lesion of the parotid gland, using real time 3.75 MHz, 5 MHz and 7.5 MHz transducers. From a histological standpoint, there were 246 benign tumors, namely 144 pleomorphic adenomas, 35 adenolymphomas, 23 other adenomas, 14 cysts, 9 neurinomas, 3 lymphomas, 9 hemangiomas, 3 lymphangiomas and 6 lymph nodes. Another 64 were malignant tumors, namely, 7 mucoepidermoid carcinomas, 7 acinic cell carcinomas, 7 adenoid cystic carcinomas, 15 adenocarcinomas, 7 squamous cell carcinomas, 4 undifferentiated carcinomas, 10 carcinomas in pleomorphic adenoma, 3 malignant lymphomas, 2 metastatic carcinomas and 2 other carcinomas. According to our criteria for ultrasonographic diagnosis of the parotid gland tumors, the benign or malignant pattern was determined by the following findings; shape, boundary echo, internal echo and posterior echo. But in some cases we could not differentiate the two echogram patterns, and we call them the intermediate pattern. The total accuracy rate of the diagnosis of the 310 patients was 79.0%. (The intermediated pattern was found in 39 patients and these cases were considered to be misinterpreted.) In 268 primary parotid gland tumors (210 benign and 58 malignant tumors) excluding recurrent cases, lymph nodes, hemangiomas and so on, the sensitivity was 62.1%, the specificity was 91.4% and the total accuracy rate was 85.1%. The accuracy of sonography in determining whether a tumor was benign or malignant was affected by the tumor size; tumors smaller than 2 cm in diameter showed a tendency to be diagnosed as benign and tumors larger than 6 cm in diameter as malignant. In the 268 cases, the importance of the pattern of the boundary echo and the internal echo in differentiating benign and malignant tumors was examined retrospectively. In the 210 primary benign tumors, the benignity of the tumors was assessed correctly in 84.3% by the boundary echo and 85.7% by the internal echo. In the 58 primary malignant tumors, the malignancy was assessed correctly in 58.6% by the boundary echo and 43.1% by the internal echo. Strong echos, which are the signs of a malignant pattern, were seen in 14.8% of the benign tumors, and in 51.7% of the malignant tumors. It can be concluded that ultrasonography is very reliable for the examination of parotid gland tumors.