18F-FDG PET/CT to differentiate malignant necrotic lymph node from benign cystic lesions in the neck

OBJECTIVE

Patients presenting with cystic lesions in the neck without obvious signs of malignancy constitute a diagnostic challenge since fine needle aspiration is often insufficient and a diagnosis may not be reached until surgical resection/biopsy is performed. The differential diagnosis of a cystic cervical mass comprises a variety of benign conditions, but malignancy must be ruled out. We examined the diagnostic performance of fluorine-18 fluorodeoxyglucose (¹⁸F-FDG) PET/CT to identify malignancy.

METHODS

We retrospectively included consecutive patients referred from the Department of ENT Head and Neck Surgery for ¹⁸F-FDG PET/CT-scans because of a solitary neck cyst. Scan results were compared to histopathology and follow-up.

RESULTS

The study comprised 58 patients. Twenty patients (34%) were diagnosed with cancer during follow-up. PET/CT suggested malignancy in 34 patients (19 true positive, 15 false positive) and showed no malignancy in 24 (23 true negative, 1 false negative). The sensitivity, specificity, accuracy, positive and negative predictive values were 95% (76-99%), 61% (45-74%), 72% (60-82%), 56% (39-71%), and 96% (80-99%), respectively (95% confidence intervals in brackets). The primary tumor was identified in 14 out of the 20 patients with confirmed cancer. Increased metabolism, as evaluated by PET, was the only imaging characteristic among several others, which associated independently with malignancy in the cystic neck lesions, odds ratio 1.27 (1.07-1.50), p = 0.006.

CONCLUSION

¹⁸F-FDG PET/CT could reliably rule out malignancy (NPV 96%), albeit with a high frequency of false positive scans, requiring further diagnostic work-up. Increased metabolism was the best imaging parameter to differentiate between malignant and benign lesions.

[Salivary stone in parotid gland with a cutaneous fistula]

Parotid fistulas are very rare and arise from various causes such as trauma, operative complications, infection, malignancy and stone. They may also be congenital. A rare case of cutaneous salivary fistula is presented. A 59-year-old man had a recurrent inflammatory parotid disease which disappeared after the expulsion of the calculus.

The Journal of Nutrition, Volume 106, 1976: Decreased absorption of calcium, magnesium, zinc and phosphorus by humans due to increased fiber and phosphorus consumption as wheat bread

During a 20 day period of high fiber consumption in the form of bread made partly from wheaten wholemeal, two men developed negative balances of calcium, magnesium, zinc and phosphorus due to increased fecal excretion of each element. The fecal losses correlated closely with fecal dry matter and phosphorus. Fecal dry matter, in turn, was directly proportional to fecal fiber excretion. Balances of nitrogen remained positive. Mineral elements were well-utilized by the same subjects during a 20 day period of white bread consumption.

Immunoperoxidase study in alpha-chain disease

Peroxidase-antiperoxidase technique was applied to search for the presence of alpha-chain protein in cells of the infiltrate from six cases of alpha-chain disease (one immunoblastic sarcoma and five plasmacytosis cases). Cases of poorly differentiated lymphocytic and Burkitt's type lymphomas, IgA myeloma, and tuberculous enteritis served as controls. Infiltrate cells from alpha-chain disease showed heavy and diffuse staining with anti-alpha-chain and not light-chain antisera. The myeloma reacted with both anti-alpha and anti-kappa antisera. Plasma cells from tuberculous enteritis showed variable staining with anti-heavy- and anti-light-chain antisera, while control lymphomas did not stain at all. We suggest that immunoenzyme histochemistry is a useful tool in demonstrating intracellular alpha-chain protein.

Primary upper small-intestinal lymphoma and alpha-chain disease. Report of 10 cases emphasizing pathological aspects

Ten cases of primary upper small-intestinal lymphoma associated with alpha-chain protein in serum were discovered in a prospective study of the sera of patients with immunoproliferative small-intestinal disease (IPSID). Patients were mostly young males presenting with abdominal pain, weight loss, and diarrhea and showing laboratory evidence of carbohydrate, fat, and vitamin B12 malabsorption and hypoalbuminemia. The more frequently encountered pathologic abnormality was a diffusely nodular jejunal mucosa produced by a plasmacytic infiltrate of variable cell maturity involving a varible depth of small bowel wall with or without involvement of the mesenteric or para-aortic-lymph node complex and, in one instance, the liver. A less frequent picture included circumferential ulcerative and constrictive transmural tumors of the upper small intestine produced by a malignant lymphoma with involvement of abdominal lymph nodes. Small-intestinal surface epithelial abnormalities, a dense mantle of mature plasma cells overlying the lymphoma, a pronounced follicular lymphoid hyperplasia adjacent to and at distances from the lymphoma were other features of note in our IPSID cases associated with alpha-chain protein.

T and B lymphocytes in alpha-chain disease

The patients studied were diagnosed as suffering from alpha-chain disease by their clinicopathological features, malabsorption findings, X-ray, and presence of abnormal alpha-chain protein in their serum. The objective of the study was to determine any possible defect of the immune system in such patients. The rosette technique and surface immunofluorescence were used to enumerate the circulating T and B lymphocytes in these patients. They were also skin-tested with tuberculin and given sensitizing doses of dinitrochlorobenzene. Their serum immunoglobulins were also quantitated. It was found that the proportion of circulating B lymphocytes was much higher than normal, whereas that of T lymphocytes was lower than normal. Furthermore, they could not be sensitized to DNCB and their skin test to tuberculin was negative. It was concluded that the disease was a B-cell disease of IgA type, associated with low level of cellular immunity.

Alpha heavy-chain disease in southern Iran

A prospective study of 32 patients with primary upper small intestinal lymphoma in our region revealed 10 cases of alpha heavy-chain disease. Patients were mostly in the second and third decades of life and males predominated. Weight loss, diarrhea, and abdominal pain were the most common complaints and clubbing the most frequent physical findings. Laboratory tests revealed a malabsorption pattern on intestinal x-rays, and malabsorption of xylose, fat, and vitamin B12 was frequently noted. Dense plasmacytic infiltrate of the lamina propria of small bowel was the most frequent pathologic finding while true neoplasm of the lymphoid system (ie, immunoblastic sarcoma) was encountered in 20% of the cases.

Role of bacterial overgrowth in the malabsorption syndrome of primary small intestinal lymphoma in Iran

Malabsorption studies were performed on five Iranian patients with primary small intestinal lymphoma. The effect of oral tetracycline (1.0 g daily) was also studied in three of the above subjects. The results of breath tests (utilizing glycine-1-14C-cholic acid) were abnormal in all five subjects before the antibiotic treatment. Oral tetracycline had a striking effect towards normalizing the results of breath tests. Schilling tests (with intrinsic factor) improve in two patients and steatorrhea improved in all and there was significant weight gain. The antibiotic had no apparent effect on D-xylose or folate absorption tests. It is concluded that bacterial overgrowth in the small intestinal lumen is an important contributory factor to the malabsorption syndrome of this disease.

Effects of cellulose added to diets of low and high fiber content upon the metabolism of calcium, magnesium, zinc and phosphorus by man

Addition of 10 g of cellulose dispersed in 150 g of apple compote to the daily diet with a low fiber content for a 20-day period caused the fecal excretion of calcium and zinc of three men to increase significantly. Balances of both metals became negative and their concentrations in plasma decreased. Magnesium balances became negative in two subjects while phosphorus balance changed to negative in one. In a similar experiment in which the cellulose was added to a fiber-rich diet, fecal excretions of calcium and zinc increased significantly in each of two men and excretion of magnesium in one. Previously negative balances became more negative, and calcium and zinc concentrations decreased in plasma. The dependence of fecal dry weight upon fecal fiber content measured by the acid-detergent method was confirmed. However, increments of dry matter per g of fiber were less fecal fiber concentrations were high. Fecal calcium content correlated significantly with fecal fiber in two subjects, and fecal fiber and zinc in one. No correlations were demonstrated in the subject who apparently digested fiber most effectively. Our findings indicate that high intakes of fiber can explain to a considerable extent the impaired utilization of zinc, calcium, and magnesium among villagers in rural Iran.

Alpha-chain disease and its association with intestinal lymphoma

Twenty-seven intestinal lymphoma patients were studied. Abnormal alpha-chain immunoglobulin was detected in the sera of seven of these patients. The alpha-chain disease patients were from the rural areas of Southern Iran. They were of low socio-economic status and their age ranged from 15-44 years. Predominant clinical features were malabsorption, diarrhoea , abdominal pain, vomiting, and weight loss. Infiltration of mucosa of the small intestine with plasma cells and also distortion and flattening of the villi were common histopathologic characteristics of these patients. Involvement of mesenteric lymph nodes with infiltration of tumour cells was observed in a number of cases. Protein studies revealed no significant differences between the serum immunoglobulin levels of these patients and normal values. Immunoelectrophoresis using monospecific antiserum against H-chain of human IgA demonstrated the abnormal precipitin band of alpha-chain disease protein.

Decreased absorption of calcium, magnesium, zinc and phosphorus by humans due to increased fiber and phosphorus consumption as wheat bread

During a 20 day period of high fiber consumption in the form of bread made partly from wheaten wholemeal, two men developed negative balances of calcium, magnesium, zinc and phosphorus due to increased fecal excretion of each element. The fecal losses correlated closely with fecal dry matter and phosphorus. Fecal dry matter, in turn, was directly proportional to fecal fiber excretion. Balances of nitrogen remained positive. Mineral elements were well-utilized by the same subjects during a 20-day period of white bread consumption.

Primary upper small-intestinal lymphomal A report of 40 cases fron Iran

Primary upper small-intestinal lymphoma (PUSIL) has now been recognized as a distinct clinical entity with a distinct geographic distribution. Herewith are presented 40 cases of PUSIL seen at Pahlavi University Hospitals in Southern Iran. The investigation reveals the lymphoma to be predominantly a disease of those under 30 and males; the major complaints and physical findings point to an intraabdominal disease. An exception has been clubbing and osteoarthropathy. Special features of PUSIL include: (1) protein loss into the gastrointestinal tract leading to hypoalbuminemia and edema; (2) an antibiotic-responsive diarrhea and steatorrhea; and (3) an associated abnormal heavy-chain protein. The study further stresses the importance of peroral small-intestinal biopsy and the pathologic features of this condition.

Idiopathic enteropathy: an evaluation in rural Iran with an appraisal of nutrient loss

Idiopathic enteropathy in the rural population of Iran was investigated through evaluation of 100 randomly selected apparently normal subjects. The evaluation included quantitation of the nutrient loss, presence of malabsorption, and small intestinal morphological abnormalities. The results show that: 1) there was no significant loss of major nutrients, 2) severe malabsorption was not present, 3) an enteropathy of unknown etiology was found in nearly one-third of the subjects, and 4) abnormalities in morphology did not necessarily mean presence of malabsorption.