Computed normal values for peak acid output based on age, sex and body weight

Current management of Helicobacter pylori infections in the elderly

Helicobacter pylori infection is a chronic gastric gram-negative infection that increases with age worldwide. However, the percentage age of H. pylori-positive elderly patients who are tested and treated for their infection remains very low. It is now demonstrated that H. pylori infection induces a whole cascade of events leading to gastric pathologies, such as peptic ulcer diseases, gastric precancerous lesions and gastric cancer. Recent data also demonstrated that H. pylori chronic infection can play a role in gastric aging, appetite regulation and extradigestive diseases, such as Alzheimer's disease, in the elderly. The diagnosis of H. pylori infection remains difficult to realize in the very old population, and the urea breath test obtains the best performance in this population. 1-week proton pump inhibitor-based triple therapy regimens are highly effective and well tolerated in elderly patients, and antibiotic resistance remains very low. Low compliance is the main factor related to treatment failure in this population.

Gastric emptying, diabetes, and aging

Gastric emptying is mildly slowed in healthy aging, although generally remains within the normal range for young people. The significance of this is unclear, but may potentially influence the absorption of certain drugs, especially when a rapid effect is desired. Type 2 diabetes is common in the elderly, but there is little data regarding its natural history, prognosis, and management. This article focuses on the interactions between gastric emptying and diabetes, how each is influenced by the process of aging, and the implications for patient management.

Infection à Helicobacter pylori chez la personne âgée

PURPOSES

Helicobacter pylori (H. pylori) infection is a chronic gastric Gram-negative infection that increases with age. Acquired in childhood, H. pylori infection may induce a whole cascade of events leading to gastric pathologies such as peptic ulcer diseases, gastric precancerous lesions, and gastric lymphomas (MALT). The characteristics of the diagnosis and the treatment of this infection in geriatrics are thus particularly important to take into account.

MAIN POINTS

1) The incidence of gastric and duodenal ulcers and their bleeding complications is increasing in old-aged populations. Clinical signs such as anorexia and malnutrition are proven to be excellent indications for endoscopic explorations in the elderly. NSAID-use and H. pylori infection were shown to be independent and unrelated risk factors for peptic ulcer and gastroduodenal bleeding in elderly subjects; 2) H. pylori infection diagnosis is difficult to realize in the very old population, and the urea breath test is the test which obtain the best performances in this population.

PERSPECTIVES

Recent work showed the part played by H. pylori chronic infection in gastric aging and in appetite regulation in the elderly. Research tasks should be continued in this field in order to better understand the part played by this chronic infection in gastric aging and in other pathologies (i.e. neurological or cardiovascular diseases) in this population.

Influence of age and gender on gastric acid secretion as estimated by integrated acidity in patients referred for 24-hour ambulatory pH monitoring

OBJECTIVES

Earlier studies have suggested that gastric acid secretion declines with age. Integrated acidity (IA) calculated from ambulatory 24-h pH studies provides an estimation of gastric acid secretion that is less cumbersome than nasogastric aspiration. The aim of this study was to calculate IA as a function of age and gender.

METHODS

In a retrospective study, 753 ambulatory 24-h pH studies from 1994 to 2001 were analyzed. Subjects were classified according to nine age groups: <35 yr (n = 124), 35-39 yr (n = 90), 40-44 yr (n = 92), 45-49 yr (n = 111), 50-54 yr (n = 96), 55-59 yr (n = 61), 60-64 yr (n = 59), 65-69 yr (n = 42), and > or =70 yr (n = 64). Basal integrated acidity (BIA) was defined as IA between 12 midnight and 8 AM when no meals were consumed. Daytime and nocturnal IA/h was measured from 8 AM to 8 PM and from 8 PM to 8 AM. Postprandial IA (PIA) was measured for 2 h after the largest meal peak in each patient.

RESULTS

Gender distribution was similar between groups (chi(2) = 6.42, 3 df, p = 0.093). Mean gastric pH was similar between genders (2.96 +/- 1.36 women; 3.01 +/- 1.42 men; p = 0.71). Women and men had similar BIA (361.1 +/- 384.1 vs 434.6 +/- 436.6 mmol/L/h, p = 0.10), daytime IA (33.5 +/- 33.0 vs 34.1 +/- 33.7 mmol/L, p = 0.90) and nocturnal IA (43.3 +/- 42.1 vs 48.0 +/- 46.6 mmol/L, p = 0.42), and PIA (38.2 +/- 58.7 vs 36.0 +/- 58.5 mmol/L/h, p = 0.47). Mean gastric pH, daytime and nocturnal IA, BIA, and PIA did not differ between age groups (p > 0.1). None of the parameters studied had a linear association with age (mean gastric pH, r = 0.106; BIA, r = -0.124; daytime IA, r = -0.046; nocturnal IA, r = -0.104; PIA, r = -0.117).

CONCLUSIONS

Based on this study, we conclude that IA is unaffected by gender or age.

Effect of age and Helicobacter pylori infection on gastric acid secretion

BACKGROUND

Whether gastric acid secretion decreases with age is still controversial. With the discovery of Helicobacter pylori, the association of this bacterium with gastric acid secretion has also been discussed. The aim of this study was to investigate the relationship between gastric acid secretion, age and H. pylori infection.

METHODS

The presence of H. pylori infection, the grade of fundic atrophic gastritis (FAG), and gastric acid secretion were investigated in 280 subjects without localized lesions in the upper gastrointestinal tract. Helicobacter pylori infection was confirmed by Giemsa and immunohistochemical staining, and FAG of biopsy specimens was graded on a scale of 0-4.

RESULTS

Both basal and maximal acid output decreased with age in H. pylori-positive subjects, while they did not change with age in H. pylori-negative subjects. Gastric acid secretion decreased with the progression of FAG. An age-correlated decrease in gastric acid secretion in H. pylori-positive subjects depended on an increasing prevalence of FAG with age.

CONCLUSIONS

In the population studied, advancing age had no influence on gastric acid secretion in H. pylori-negative subjects. Gastric acid secretion decreases with age in H. pylori-positive subjects because of the increasing prevalence of FAG with age.

Mechanisms of drug-induced diarrhoea in the elderly

In the rapidly increasing elderly population, diarrhoea as a result of drug therapy is an important consideration. The elderly consume a disproportionately large number of drugs for multiple acute and chronic diseases. Drugs can compromise both immune and nonimmune responses. Aging decreases the quality and proportion of T cells which in turn reduces the production of secretory IgA, the primary immune response of the gut. Acid production in the stomach decreases with increasing age and this compromise its vital 'self-sterilising' function, thus increasing the risk of diarrhoea due to viral, bacterial and protozoal pathogens. Other nonimmune defence mechanisms include the motility of the small intestine and the host-protective commensal bacteria of the colon. Drug induced hypomotility may result in bacterial overgrowth, deconjugation of bile salts and diarrhoea. Less commonly, diarrhoea may occur due to hypermotility because of a cholinergic-like syndrome. In the colon the host-protective commensal bacteria provide a powerful defence against pathogens. Disruption of this commensal population by antibiotic therapy may result in Clostridium difficile supra-infection which causes diarrhoea through toxin production. This is especially important in the elderly patient on chemotherapy for malignancy and those with multiple diseases. The organism responds to vancomycin, metronidazole and bacitracin. Metronidazole is the suggested drug of choice, with vancomycin reserved for relapses. Drugs also cause diarrhoea by interfering with normal physiological processes. Drugs impair fluid absorption by activating adenylate cyclase within the small intestinal enterocyte which increases the level of cyclic AMP. This causes active secretion of Cl- and HCO3-, passive efflux of Na+, K+ and water and inhibition of Na+ and Cl- into the enterocyte. Examples of these drugs (secretagogues) are bisacodyl, misoprostol and chenodeoxycholic acid (used to dissolve cholesterol gallstones). Drugs may also affect a second mechanism that regulates water and electrolyte transport, the Na+, K+ exchange pump. The energy for this pump is provided by the ATPase mediated breakdown of ATP. ATPase may be inhibited by digoxin, auranofin, colchicine and olsalazine. A number of drugs cause osmotic diarrhoea including antacids containing magnesium trisilicate or hydroxide. Lactulose is being used increasingly in compensated liver disease to increase protein tolerance and prevent hepatic encephalopathy. Sorbitol, an osmotic laxative agent also used in some liquid pharmaceutical preparations, induces diarrhoea by virtue of its osmotic potential. Another mechanism by which drugs cause diarrhoea is by mucosal damage of the small and large bowel. In the small intestine mucosal damage causes diarrhoea and fat malabsorption, as may occur with neomycin and colchicine. In the colon, for example, gold salts and penicillamine cause colitis of varying severity. Though the causes of diarrhoea are diverse, a drug-associated aetiology should always be considered and actively sought and addressed to prevent the complications of dehydration, electrolyte imbalance and undernutrition.

Effect of age, Helicobacter pylori infection, and gastritis with atrophy on serum gastrin and gastric acid secretion in healthy men

Gastric acid secretion has been considered to decline with increasing age but this view is being re-evaluated as the importance of Helicobacter pylori infection emerges. This study aimed to determine the effect of age, H pylori, and gastritis with atrophy on the serum gastrin concentration, gastric secretory volumes, and acid output in healthy, asymptomatic men. Young men (mean (SD) age 22.9 (0.6) years; n = 22) were compared with old men (72.9 (1.2) years; n = 28) in respect of basal serum gastrin and basal, sham fed, pentagastrin stimulated maximal and peak acid secretion. Antral, corpus, and fundal biopsy specimens were taken for histology and H pylori status (histology, culture, and rapid urease test). H pylori associated gastritis was present in three of 22 young (13.6%) and 16 of 28 old (57.1%) men. Gastritis with atrophy was present in 11 old subjects, 10 of whom were H pylori positive. These subjects had higher mean (SD) serum gastrin concentrations than old subjects without atrophy and young subjects (61.8 (9.2); 40.0 (2.9); 36.8 (2.3) pmol/l respectively; p < 0.001). H pylori infected subjects had higher gastrin values than uninfected subjects, overall (55.3 (5.9); 36.0 (1.8) pmol/l; p < 0.001) and in subjects without atrophy (45.3 (4.2); 36.0 (1.8) pmol/l; p < 0.03). In subjects without H pylori infection, gastrin values did not differ with age (old 37.1 (1.7); young 35.4 (2.1) pmol/l). The maximal gastric secretory volume was lower in old subjects with atrophy. Acid output (mmol/h) in subjects with atrophy was lower than in subjects with no atrophy (basal: 3.0(1.1); 5.1(0.7); p=NS; sham led: 5.4 (1.4); 9.3 (0.8); p<0.02; maximal: 18.9 (4.0); 31.4(1.8); p<0.002; peak: 25.1(5.3); 43.4(2.7); p<0.003). However, acid secretion in old subjects without atrophy was not different to that in young subjects, irrespective of H pylori status. These results did not differ when acid output was expressed as mmol/h/kg lean body mass or mmol/h/kg fat free body weight. Using multiple linear regression analysis, gastritis with atrophy was the only factor that had an independent negative effect on acid secretion. In healthy men without atrophy, gastric acid secretion is preserved with ageing and is independent of H pylori status. Atrophy, which is closely related to H pylori infection, is associated with a decline in acid secretion. Increased basal serum gastrin is related to both atrophy and H pylori infection but not to ageing per se.

Influence of the method of digestive tract reconstruction on gallstone development after total gastrectomy for gastric cancer

The aim of this study was to evaluate whether total gastrectomy performed for gastric cancer leads to an increased risk of cholelithiasis and whether the method of reconstruction of the digestive tract influences that risk. A total of 102 patients who had undergone total gastrectomy for gastric cancer between 1980 and 1990 were studied. The preoperative prevalence of cholelithiasis was 4% in men and 12% in women. Eighty-seven patients (85%) without gallstones before surgery were reexamined after gastrectomy. The postoperative prevalence of cholelithiasis in this group was 36% in men and 19% in women. Before surgery, the difference between the expected frequency of cholelithiasis (calculated on the basis of the data of a community survey) and the observed frequency was not statistically significant (p > 0.05) either in men or women. After surgery, the observed frequency of gallstones was significantly higher than the expected frequency in men (p < 0.0001) but not in women (p = 0.06). The risk of cholelithiasis was significantly higher in patients with Roux-en-Y reconstruction (n = 55) than in those with jejunal interposition (n = 32) (log-rank test, p = 0.03), and that risk was independent of age, sex, and body mass index.

Effect of age on gastric acid secretion and serum gastrin concentrations in healthy men and women

The effects of age on basal, meal-stimulated, and human gastrin-17-stimulated gastric acid secretion rates and serum pepsinogen concentrations were evaluated in 41 healthy men and women. Older subjects (ages 44-71 years; mean, 57 years) had higher mean basal, meal-stimulated, and gastrin-17-stimulated acid secretory rates and basal serum pepsinogen I and II concentrations than younger subjects (ages 23-42 years; mean, 33 years). Age-related differences in acid secretion were especially prominent in men, and age-related differences in serum pepsinogen I and II concentrations were more prominent in women. Higher gastric acid secretion rates in older subjects could not be explained by body size (height, weight, body surface area, or fat-free body mass) or by the higher incidence of infection with Helicobacter pylori. Using a multivariate linear regression model, age had an independent positive effect on acid secretion, and H. pylori infection had an independent negative effect. It was concluded that aging is associated with an increase in gastric acid secretion in humans, especially in men, while infection with H. pylori is associated with lower acid secretion rates.

Zollinger-Ellison syndrome. Relation to Helicobacter pylori-associated chronic gastritis and gastric acid secretion

Since Helicobacter pylori infects the gastric mucosa in most patients with chronic duodenal ulcer, infection with this organism has been implicated in the pathogenesis of this common disease. We postulated that if H. pylori is pathogenic in the usual type of duodenal ulcer, it should be less common when duodenal ulcer has another, specific etiology, such as Zollinger-Ellison syndrome. Gastric mucosa was compared from 18 patients with proven Zollinger-Ellison syndrome (17 of whom had had duodenal ulcer disease) and 18 controls with chronic duodenal ulcer without such a diagnosis. All subjects, who were matched for age and sex, had undergone elective gastric resections. Gastric tissues were stained by hematoxylin-eosin and Giemsa and were reviewed by an experienced pathologist who was unaware of the diagnosis. The frequency of H. pylori in patients with Zollinger-Ellison syndrome (8/18) was lower than in controls with duodenal ulcer (16/18; P less than 0.02). Moreover, chronic antral gastritis scores were higher in patients with duodenal ulcer (P less than 0.01). In Zollinger-Ellison syndrome, peak acid output was lower in patients positive (median 22 meq/30 min) compared to those negative for H. pylori (median 32 meq/30 min; P less than 0.02) but serum gastrin was correspondingly lower in patients positive for H. pylori (P less than 0.05). H. pylori infection appears to be more frequent when duodenal ulceration is not associated with another etiology, such as acid hypersecretion in Zollinger-Ellison syndrome. H. pylori infection in Zollinger-Ellison syndrome may also be associated with decreased gastric acid secretion.

Nutritional requirements of the aged

The age of the population continues to increase. At the turn of the century, 4% (about 3.1 million people) were 65 years of age or older. Today the percentage has increased to 12%, or 27.4 million people, and the prediction for the 21st century may increase to 17 to 20%. It should be noted that the number of individuals 85 years of age and older, as well as those over the age of 100, is increasing rapidly. The nutritional problems of the elderly are related to physiological decline, to low economic status and limited food consumption, and to a multitude of disease processes and the therapeutic regimens prescribed to cure or treat those illnesses. Examined as a group, the elderly at first appear to be less uniform in their health status than younger members of the population. However, only 10% of the elderly population contributes to the disproportionate (30%) expenditure of health care services. A majority of the elderly are normal, healthy individuals. Yet, with each decade of life the percentage of the elderly population needing additional care increases. The national nutritional surveys (National Food Consumption Survey and the National Health and Nutrition Examination Surveys, I and II) used entirely different methodologies, but reported very similar findings. The mean intake of this population was actually quite good, revealing low intakes of calcium and iron in the elderly female population. However, the standard deviation of the intake data strongly suggests a major portion of the population is at nutritional risk. For more than 30% of the population, nutrient intakes below two thirds of the recommended dietary allowances (RDA) occurred for calories, calcium, and vitamin A, while for more than 20% of the population, iron and vitamin C were at risk. Although the data evaluating the effects of age on the nutritional requirements of the elderly are limited, careful interpretation of the existing assessment and intervention efforts can provide some basic guidelines. Generalities about calorie intake must be avoided, and emphasis must be placed on calorie needs. Enhanced activity should be encouraged. Protein intake for the majority of elderly exceeds the RDA, but with increased age a greater amount of high quality protein is needed to maintain nitrogen balance. The group at greatest risk is the poor elderly who may not be able to afford enough high quality protein. Increased consumption of complex carbohydrates serves several functions including decreased caloric density and enhanced nutrient intake. Decreasing total dietary fat decreases caloric intake and indirectly decreases dietary cholesterol.(ABSTRACT TRUNCATED AT 400 WORDS)

Maintenance treatment with ranitidine compared with fundoplication in gastro-oesophageal reflux disease

The study comprises 31 patients with gastro-oesophageal reflux disease who received 8 weeks' treatment with ranitidine. Sixteen of the patients received in addition maintenance treatment with ranitidine (150 mg twice daily) for another 6 months, and fundoplication was performed on 15 patients. There was a significant improvement in endoscopic and histologic findings, a decrease in gastric acid secretion, and a reduction of symptoms during short-term treatment with ranitidine. No further improvement was seen in any of the factors after half a year of ranitidine. After surgery the total reflux time during 24 h decreased to practically zero, all patients had normal endoscopic findings and negative acid perfusion tests, and reflux symptoms had disappeared completely. Anti-reflux surgery was superior to treatment with ranitidine. Reflux oesophagitis is therefore not improved any further by a half year's treatment with ranitidine beyond what is achieved with short-term therapy.

Oesophagitis, signs of reflux, and gastric acid secretion in patients with symptoms of gastro-oesophageal reflux disease

In a study comprising 100 patients referred to a surgical clinic with symptoms suggestive of gastro-oesophageal reflux disease the value of different diagnostic procedures was investigated. Positive acid perfusion and 24-h pH tests were the commonest findings. Forty-nine per cent showed a normal oesophageal mucosa or diffuse oesophagitis at endoscopy. The severity of heartburn and regurgitation did not differ between patients with normal oesophageal mucosa and oesophagitis of various severities. The severity of macroscopic oesophagitis was significantly correlated to the total reflux time, the presence of reflux or a hiatal hernia at radiology, an open cardia or reflux at endoscopy, pressure transmission or reflux and low lower oesophageal sphincter pressure at manometry. Gastric hypersecretion was found in 66% of the patients. Gastric acid secretion was not correlated to the severity of oesophagitis or to the findings at 24-h pH test. In patients with severe oesophagitis the sensitivity for radiologic, manometric, and endoscopic signs of incompetence of the gastro-oesophageal junction was 94%.

Gastric secretion and reflux pattern in reflux oesophagitis before and during ranitidine treatment

Ranitidine (150 mg X 2) and placebo were given to 42 patients with reflux oesophagitis for 8 weeks by the double-blind crossover technique. Gastric secretion tests and 24-h pH monitoring at two different oesophageal levels were performed before and during the treatment periods. Gastric hypersecretion was present in 76%. Ninety-seven per cent had reflux for more than 1% of 24 h, and 67% for more than 4.2%. Ranitidine reduced basal and stimulated gastric acid output and secretion rates (p less than 0.001), total reflux time to the lower level (p less than 0.05), and number of reflux episodes to the upper and lower levels of the oesophagus in the supine position. Basal, maximal, and peak acid output, gastric secretion rates, number of reflux episodes, and total reflux time at the upper oesophageal level in the supine position were significantly more reduced in symptomatic responders than in non-responders. No correlation was found between ranitidine-induced reduction of gastric secretion and length of oesophageal reflux time.

High serum gastrin levels in thyrotoxic patients

High gastrin levels were found in twenty-one out of fifty-six consecutive patients (38%) with thyrotoxicosis. Following return to euthyroidism gastrin levels generally fell, but twelve patients (21%) remained hypergastrinaemic. Six of these patients (11%) had achlorhydria indicating atrophic gastritis of the antrum sparing type. No correlation between gastrin and triiodothyronine values was found. It is suggested that gastrin levels should be measured in thyrotoxic patients after treatment, and further control instituted in patients with raised gastrin levels. The relationship between gastric function, gastrin release and thyroid function seems complex. The interactions may involve both a direct effect of thyroid hormone on gastric acid production, adrenergic influences on gastrin release and linked phenomena with development of thyroid and gastric auto-immune diseases.

Gastric acid secretion in uraemia and circulating levels of gastrin, somatostatin, and pancreatic polypeptide

Basal circulating levels of gastrin, somatostatin, and pancreatic polypeptide were measured in 30 chronic haemodialysis patients. Five patients had considerably raised serum gastrin (greater than 400 pmol/1) and also gastric achlorhydria while 75% of the patients who had normal (less than 55 pmol/1) or moderately increased (less than 400 pmol/1) serum gastrin had raised maximal acid outputs. Patients with serum gastrin greater than 400 pmol/1 had significantly lower plasma concentrations of somatostatin compared with both healthy individuals and uaremic patients with normal gastrin levels. Raised serum concentrations of pancreatic polypeptide were observed in the majority of the patients but no correlation was found between this peptide and gastric acid secretion or circulating levels of gastrin and somatostatin, respectively. Prolonged circulation time for gastrin and pancreatic polypeptide was demonstrated after food stimulation. Prolonged gastrin stimulation of the parietal cell mass may lead to work hypertrophy and gastric acid hypersecretion. Whether long-standing over-stimulation by gastrin also may induce atrophy of the cells remains to be studied.

Adenylate cyclase in human gastric mucosa: its activation by histamine in morphologically different biopsy specimens

In morphologically different biopsy specimens from fundic, antral and duodenal mucosa of 134 persons, basal and histamine stimulated adenylate cyclase activity was studied: Basal and stimulated adenylate cyclase activities were log-normally distributed. Only in the fundic but not in the antral and duodenal mucosa adenylate cyclase was sensitive to histamine. The mean basal activity in the fundic gastric mucosa was 148, in response to 10(-5) mol/l histamine 292 pmol cAMP/mg protein/20 min. In human fundic biopsy specimens histologically identified as normal gastric mucosa, the stimulatory effect of histamine on adenylate cyclase decreased with the individual's age. In bioptic material from patients suffering from histologically proven chronic gastritis the histamine effect decreased with the degree of atrophy. A similar loss of histamine sensitivity was found in gastric mucosal biopsies of antrectomized individuals operated at least 5 years before by the Billroth I or II method, whereas in the mucosa of patients with gastric or duodenal ulcer no loss occurred. In contrast, the most pronounced stimulatory action of histamine was found in this latter group. Since a histamine sensitive adenylate cyclase is localized only in the glandular area of the fundic mucosa and the histamine sensitivity depends on a morphological intact structure of the mucosa, it can be concluded, that the effects of histamine on adenylate cyclase and on hydrochloric acid acid secretion have to be considered as a mechanism linked together.

Interpretive reporting of laboratory data. Gastric analysis

The reporting of gastric analysis data requires clearly formatted and documented analytic results, accurately calculated secretory rates, appropriate normal values based on age, sex and weight of the patient, and interpretive review of the data based on well-documented personal experience or comprehensive studies reported in the medical literature. We report here a technique using inexpensive and flexible data processing equipment suitable to most community hospital laboratories.

Propantheline bromide in massive upper gastrointestinal haemorrhage

The effectiveness of the anticholinergic, propantheline bromide, administered parenterally in patients with upper gastro-intestinal bleeding has been investigated in a double-blind study. The basic material consisted of 99 patients. No differences were found between the group receiving propantheline bromide and the group receiving placebo in regard to clinical factors such as duration of intensive care, total hospital stay and surgical frequency. However, 21 patients under 50 years of age showed a significantly lower blood transfusion requirement with the use of propantheline bromide.

Gastric mucosal morphology and faecal blood loss during ethanol ingestion

The faecal blood loss of six alcoholic subjects with normal gastric mucosa, six with superficial gastritis, and six with atrophic gastritis was studied before and during ingestion of 40% v/v ethanol using (51)Cr-tagged red blood cells. No significant change in faecal blood loss was observed in the normal mucosa and superficial gastritis groups but all subjects with atrophic gastritis had significant increases of faecal blood loss during ethanol ingestion. These observations suggest that gastric mucosal morphology may be an important determinant of gastric mucosal bleeding during the ingestion of alcohol.

Salivary secretion in duodenal ulcer disease

Salivary response to stimulation with citric acid was higher in patients with duodenal ulcer disease than in patients with other diseases of the upper gastrointestinal tract. This increase was proportional to an increase of histamine-stimulated gastric acid secretion. In duodenal ulcer disease, the increase in parietal cell mass may therefore be associated with the growth of other exocrine organs such as the salivary glands.