A multiplex RT-PCR assay for analysis of relative transcript levels of different members of multigene families: application to Arabidopsis calmodulin gene family

In systemic amyloidosis, widespread amyloid deposition interferes with organ function, frequently with fatal consequences. Diagnosis rests on demonstrating amyloid deposits in the tissues, traditionally with histology although scintigraphic imaging with radiolabeled serum amyloid P component (SAP) has lately been developed as a specific noninvasive alternative. We report a detailed analysis of the abnormal turnover of SAP in patients with systemic amyloidosis and an assessment of its clinical value. METHODS: Iodine-123-labeled human SAP (200 MBq) SAP was injected intravenously into 49 patients with histologically proven systemic AA- or AL- amyloidosis and in 7 control subjects. Plasma clearance and whole-body retention of labeled SAP were analyzed over 48 hr using plasma sampling, whole-body gamma camera imaging and measurement of radioactivity in the urine. The rate of SAP synthesis and interstitial exchange were determined, and the size of the amyloid compartment was compared with clinical estimates of whole-body amyloid load and patient survival. RESULTS: All plasma time-activity curves were biphasic. In comparison with control subjects, patients with amyloidosis showed significantly faster plasma disappearance [4-hr value: AA 48% +/- 18%, AL 45% +/- 15% versus 65% +/- 8% (p < 0.05)], higher total-body retention 48 hr p.i. [AA 74% +/- 14%, AL 73% +/- 17% versus 46% +/- 15% (p < 0.01)] and especially higher extravascular retention 48 hr p.i. [AA 59% +/- 16%, AL 58% +/- 19% versus 30% +/- 14% (p < 0.01)]. Extravascular retention correlated with clinical estimation of the amyloid load. If extravascular retention values in patients with AL amyloidosis were over 60%, survival was decreased (median 4 versus 23 mo, p < 0.001). Markedly increased interstitial exchange rates were present in amyloidosis (AA 64 +/- 61, AL 50 +/- 37 versus 18 +/- 8 mg/hr), whereas the SAP synthesis rate did not differ from the control values (AA 5.0 +/- 3.0, AL 5.5 +/- 3.2 versus 4.5 +/- 1.4 mg/hr). CONCLUSION: The presence of systemic amyloidosis is characterized by accelerated initial clearance of 123I-SAP from the plasma and increased interstitial exchange rate and extravascular retention. These findings reflect reversible binding of radiolabeled SAP to amyloid deposits and provide clinically useful information for diagnosis, monitoring of therapy and prognosis in patients with systemic amyloidosis.     

Serum amyloid P component scintigraphy in familial amyloid polyneuropathy: regression of visceral amyloid following liver transplantation

Familial amyloid polyneuropathy (FAP) associated with transthyretin (TTR) mutations is the commonest type of hereditary amyloidosis. Plasma TTR is produced almost exclusively in the liver and orthotopic liver transplantation is the only available treatment, although the clinical outcome varies. Serum amyloid P component (SAP) scintigraphy is a method for identifying and quantitatively monitoring amyloid deposits in vivo, but it has not previously been used to study the outcome of visceral amyloid deposits in FAP following liver transplantation. Whole body scintigraphy following injection of iodine-123 labelled SAP was performed in 17 patients with FAP associated with TTR Met30 and in five asymptomatic gene carriers. Follow-up studies were performed in ten patients, eight of whom had undergone orthotopic liver transplantation 1-5 years beforehand. There was abnormal uptake of 123I-SAP in all FAP patients, including the kidneys in each case, the spleen in five cases and the adrenal glands in three cases. Renal amyloid deposits were also present in three of the asymptomatic carriers. Follow-up studies 1-5 years after liver transplantation showed that there had been substantial regression of the visceral amyloid deposits in two patients and modest improvement in three cases. The amyloid deposits were unchanged in two patients. In conclusion, 123I-SAP scintigraphy identified unsuspected visceral amyloid in each patient with FAP due to TTR Met30. The universal presence of renal amyloid probably underlies the high frequency of renal failure that occurs in FAP following liver transplantation. The variable capacity of patients to mobilise amyloid deposits following liver transplantation may contribute to their long-term clinical outcome.     

Serum amyloid P component scintigraphy and turnover studies for diagnosis and quantitative monitoring of AA amyloidosis in juvenile rheumatoid arthritis

OBJECTIVE: To evaluate aspects of the natural history of AA amyloidosis complicating juvenile rheumatoid arthritis (JRA), and its response to therapy with chlorambucil. METHODS: Scintigraphy and 7-day turnover studies were performed in JRA patients with histologically proven (n = 35) or clinically suspected (n = 30) AA amyloidosis, following intravenous injection of 123I and 125I-labeled serum amyloid P component (SAP). Prospective monitoring studies were performed over 2-3 years in 20 patients with amyloidosis. All but 2 amyloidosis patients were treated with chlorambucil. RESULTS: Positive scanning results were obtained in all patients in whom imaging was performed within 12 years of positive biopsy findings of amyloid and in 5 patients with clinically suspected amyloidosis. Negative scanning results with normal SAP metabolism, indicating regression of amyloid, were obtained in 4 patients whose amyloidosis had been in full clinical remission for more than 12 years. Prospective monitoring studies in patients whose JRA-associated inflammatory activity was in remission demonstrated regression of amyloid in 8 patients and no substantial changes in 8 others; however, in 4 further patients with active inflammation, there was accumulation of amyloid. There was a very poor correlation between the amount of amyloid present at a particular site and the resultant organ dysfunction. CONCLUSION: Radiolabeled SAP scintigraphy and turnover studies are useful complementary tools in the diagnosis, screening, and quantitative monitoring of type AA amyloidosis in JRA. The amyloid deposits may progress and/or regress at different rates in different anatomic sites over short periods.     

Amyloidosis: a review of recent diagnostic and therapeutic developments

Amyloid deposition is associated with a diverse range of disorders that includes Alzheimer's disease, type II diabetes mellitus and dialysis arthropathy. Although less common, systemic AA and AL amyloidosis remain important because effective treatments have increasingly become available. The pathology in all forms of amyloidosis involves the extracellular deposition of protein as characteristic fibrillar aggregates which interfere with tissue structure and function. Amyloid fibrils are derived from different unrelated proteins in the different forms of the disease but share many common properties, including the capacity to bind the normal plasma protein serum amyloid P component (SAP). This is the basis for our development of radiolabelled SAP as a nuclear medicine tracer for the diagnosis and quantitative monitoring of amyloid. Serial studies have shown that the deposits are far from inert but are actually turned over quite rapidly in many patients. The treatment of amyloidosis involves supportive measures whilst every effort is made to reduce the supply of the respective fibril precursor protein. Under favourable circumstances further amyloid deposition will be prevented. existing deposits will regress and improvement of organ function will occur. Since this strategy is not always possible or may fail, new approaches to inhibit fibril formation and promote regression of amyloid are being pursued.     

Laboratory findings and serum levels of amyloid A and soluble interleukin-2 receptors in patients with renal amyloidosis

BACKGROUND: Renal amyloid involvement results either from primary or secondary amyloidosis. Extent of amyloid tissue deposition in kidneys and clinical course depends not only on the type of basic process but reflects also time of diagnosis and possibility to influence the basic process. METHODS AND RESULTS: We analyzed laboratory and clinical data of patients with bioptically proven renal amyloidosis. We found renal amyloidosis in 27 patients from an overall number of 750 renal biopsies (RB) performed in our department (i.e. 3.6%). AA amyloidosis was diagnosed in 16 pts, AL amyloidosis in 11 pts. About 50% of patients had laboratory signs of nephrotic syndrome, all patients had various degree of proteinuria. Impaired renal function were found in more than 50% of patients, in 6 of them we had to start renal replacement therapy. 8 pts died. Complications of severe nephrotic syndrome were the causes of death in majority of cases. We have started investigation of some amyloid precursors and cytokines in patients with AA and AL amyloidosis. We compared the results with group of patients with vasculitis. We investigated plasma and urinary levels of SAA (serum AA) and soluble receptor for interleukin 2 (sIL-2R). CONCLUSIONS: Clinical features and laboratory findings in our patients with renal amyloidosis approximately are in accordance with literary data. Plasmatic level of SAA was increased not only in the group of patients with AA amyloidosis, but also in the group of vasculitis. Urinary sIL-2R was significantly increased in patients with AA amyloidosis in comparison with healthy controls.     

Primary amyloidosis--involving principally intrarenal blood vessels

We analysed renal biopsies from 34 nephrotic patients with renal amyloidosis, seven with primary form kappa chain (AL amyloidosis) and 27 with secondary amyloidosis associated with the other chronic diseases. Renal biopsy specimens were analysed using optical and immunofluorescence microscopy. The extent of amyloid deposits was graded from 0 to + + + +. Intrarenal blood vessel deposits were more prominent than intraglomerular in five of seven patients with AL amyloidosis, while they were identical in one, and in one, intraglomerular amyloid deposits were dominant. The results were different in the group of patients with secondary amyloidosis: a lower degree of intrarenal blood vessels deposition than glomerular was noted in 22 of 27 cases, the degree of deposition was identical in 4 of 27 cases and more expressed blood vessel deposition was present in only one case. Granular or combined deposits (granular+linear) were found on immunofluorescence microscopy in primary form, but the dominant form of deposition was amorphous in secondary amyloid.     

Amyloid light-chain amyloidosis with primary involvement of the cardiorespiratory system--2 case reports

The authors describe the cases of two women suffering from AL amyloidosis with affection of the heart muscle in particular. In one of the patients there were also massive amyloid deposits in the lungs which is an exceptional finding. The observations confirm the adverse prognosis of amyloidosis, the rapid progression of the disease after the onset of symptoms of cardiac failure. The first cardial manifestation in both patients were palpitations. The first patient, but not the second one, had a myeloma confirmed on necropsy.     

Nonsecretory immunoglobulin-derived amyloidosis of the heart: diagnosis by immunohistochemistry of the endomyocardium

Primary amyloid light chain (AL) amyloidosis of the heart is a rare cause of congestive heart failure. Approximately 15% of patients with primary AL amyloidosis demonstrate no monoclonal proteins on serum or urine immunoelectrophoresis:(so-called nonsecretory immunoglobulin-derived amyloidosis). The histologic findings of endomyocardial biopsy from these patients may be indistinguishable from those with senile cardiac amyloidosis. However, the AL type may respond favourably to chemotherapy while the latter type does not. The prognosis is also better in the senile cardiac amyloid type. The precise diagnosis in the present case was made by applying immunohistochemical techniques on cardiac tissues.     

Development of gastrointestinal beta2-microglobulin amyloidosis correlates with time on dialysis

Dialysis-associated beta2-microglobulin (beta2m) amyloidosis affects predominantly musculoskeletal tissue, but visceral involvement also occurs. To evaluate the clinical significance and prevalence of gastrointestinal beta2m amyloidosis, we studied hemodialysis patients admitted for gastrointestinal-related complaints. Hemodialysis patients (excluding those with non-beta2m amyloidosis) who were admitted with gastrointestinal complaints from 1984 to 1994 were identified. Gastrointestinal tissues from patients with available autopsy or surgical specimens were examined using hematoxylin and eosin stain, Congo red stain, and beta2m immunostain. Each case was evaluated independently by two pathologists and scored for quantity and location of beta2m amyloid and associated pathology. Of 24 patients, eight (four men and 4 women) had beta2m amyloid deposits within the gastrointestinal tract. Acute clinical presentation ranged from abdominal pain to gastrointestinal bleeding and was not significantly different for patients with or without gastrointestinal beta2m amyloid deposits. However, the mean time on dialysis of 15.3 +/- 5.7 years (range 6-24 years) for patients with gastrointestinal beta2m amyloidosis was significantly greater than that of patients without gastrointestinal beta2m amyloidosis (10.5 +/- 7.0 years, range <1 to 22 years, p < 0.05). Vascular histopathology ranged from mild focal thickening of vessel walls to massive vascular beta2m amyloid deposition with thrombosis. Extravascular beta2m amyloid ranged from mild to severe with marked expansion of the submucosa. Mucosal pathology ranged from none to severe ulceration. The degree of beta2m amyloid and the associated pathology tended to increase in severity with time on dialysis. Gastrointestinal beta2m amyloid deposition is an underappreciated complication of chronic hemodialysis that is significantly associated with increased time on dialysis. Gastrointestinal beta2m amyloidosis should be considered in any patient on hemodialysis 10 years or more who has gastrointestinal symptoms and can be identified in resection specimens as well as some biopsy specimens. Congo red stain and beta2m immunostains may be necessary for sensitive histopathologic evaluation of gastrointestinal beta2m amyloidosis.     

Signal-averaged electrocardiography in patients with AL (primary) amyloidosis

One hundred thirty-three patients with biopsy-proven AL amyloidosis were studied with echocardiography, Holter recording, 12-lead electrocardiography, and signal-averaged electrocardiograms. Features from these tests were analyzed in relation to their effect on mortality. Late potentials were more frequent in patients with echocardiographic evidence of cardiac amyloidosis (31%) compared with patients with normal echocardiograms (9%, p < 0.003). One hundred six of the 133 patients died during follow-up, of which 34 were nonsudden cardiac deaths and 33 were sudden deaths. Abnormal echocardiograms and signal-averaged electrocardiograms were each predictive of all-cause cardiac death (p < 0.0001 ) and sudden cardiac death (p < 0.0001). Abnormal signal-averaged electrocardiograms were also independently predictive of sudden death in the subgroup of patients with an abnormal echocardiogram (p < 0.05). Thus late potentials are predictive of sudden death in patients with AL amyloidosis and provide independent prognostic information in patients with echocardiographic evidence of amyloid involvement.     

Localizations and consequences

The symptoms of amyloidosis depend on the type of precursor, the amount of deposits and their location. In systemic amyloidosis almost every organ may be involved. Cardiac involvement is severe, especially in AL amyloidosis, responsible for restrictive cardiomyopathy with right ventricular failure, leading rapidly to death. Renal amyloid deposition causes nephrotic syndrome with hypertension and renal failure. Neurological complications include peripheral neuropathy with dysautonomia cerebral involvement (dementia, cerebral haemorrhages). Arterial deposits are common in systemic senile amyloidosis, and may cause ischaemia. Osteo-articular damage is mainly seen in patients on long-term haemodialysis. Liver enlargement is often the only manifestation of hepatic amyloidosis. Digestive tract involvement includes macroglossia deposits in salivary glands and disturbances in gastrointestinal motility. Pulmonary amyloidosis causes nodular or interstitial infiltrates. Cutaneous lesions are various. Localized amyloidoses include goiter, breast and vesical involvement which can be difficult to differentiate from neoplasm, as well as ocular amyloidosis mimicking posterior uveitis.     

Allogeneic bone marrow transplantation for systemic AL amyloidosis

Low-intensity chemotherapy is ineffective in most patients with AL amyloidosis, probably because clinical benefit requires regression of the amyloid deposits, and this occurs only very gradually after the underlying plasma cell dyscrasia has been suppressed. We report the first successful allogeneic bone marrow transplant (allo-BMT) for AL amyloidosis, which after 3 years was associated with complete clinical recovery. This supports the idea that there may be a brief window of opportunity in patients with AL amyloidosis during which dose-intensive chemotherapy is feasible and most likely to produce clinical benefit.     

Primary systemic amyloidosis with delayed progression to multiple myeloma

BACKGROUND: Primary systemic amyloidosis (AL) and multiple myeloma both are clonal plasma cell proliferative disorders. Although 10-15% of patients with myeloma have coexisting primary amyloidosis, it is unusual for patients with primary amyloidosis to progress to myeloma at a later date. The authors describe a case series of six patients in whom such progression occurred. METHODS: A computerized search was done of the medical records of all patients seen at the Mayo Clinic between January 1, 1960 and December 31, 1994 with a diagnosis of AL. Of 1596 patients with AL, 6 patients (age range, 60-74 years; median age, 68 years) with biopsy-proven AL were reviewed in whom delayed (at least 6 months after the diagnosis of AL) progression to multiple myeloma occurred. RESULTS: At the time of the diagnosis of AL, none of the six patients had evidence of multiple myeloma. The dominant manifestation of AL was peripheral neuropathy in three patients and cutaneous AL, renal AL, and amyloid arthropathy in one patient each. The diagnosis of multiple myeloma was made 10-81 months after the diagnosis of AL, based on the demonstration of multiple osteolytic lesions (4 patients) or marked bone marrow infiltration (> or = 50%) by plasma cells (5 patients). Two patients had received chemotherapy (melphalan and prednisone) for AL. Five patients received chemotherapy (four patients) or high dose methylprednisolone (one patient) after the diagnosis of multiple myeloma. Five patients died, and the median actuarial survival after the diagnosis of multiple myeloma was 20 months. Multiple myeloma was the cause of death in four patients; one patient died of systemic amyloidosis. In 2 patients death occurred within 3 months. CONCLUSIONS: AL occasionally progresses to overt multiple myeloma. These cases usually occur in patients without significant cardiac or hepatic AL who live long enough to develop multiple myeloma.     

Ribosomal DNA internal transcribed spacer sequences do not support the species status of Ampelomyces quisqualis, a hyperparasite of powdery mildew fungi

Amyloid P component (AP) and apolipoprotein E (Apo E), which are known to be minor constituents of amyloid deposits, commonly are associated with almost all types of amyloid deposits. In this study, the distribution of AP-, Apo E- and ubiquitin (Ub)-immunoreactivity (IR) in amyloid deposits in the liver and spleen of human systemic amyloidosis (34 autopsy cases: 17 immunoglobulin light chain derived, 17 amyloid A protein derived) and experimental murine amyloidosis is examined using an immuno-histochemical technique. In human cases, all of the amyloid deposits examined showed colocalization of AP- and Apo E-IR with individual amyloid proteins. In experimental amyloidosis, AP-IR of amyloid deposits in the liver and spleen and Apo E-IR in the liver were seen uniformly throughout this experiment. In contrast, Apo E-IR in the spleen was not uniform at the phase of amyloid deposition. At 4 weeks and at 16 weeks after casein injection, Apo E-IR was unevenly distributed in amyloid deposits in the perifollicular area; however, from 6 to 12 weeks it was seen to be uniform. Ubiquitin-IR of amyloid deposits in human cases was seen in 22 of 34 livers and in 22 of 33 spleens. In experimental amyloidosis, Ub-IR of amyloid deposits was demonstrated in the space of Disse in all mice examined, and there appeared to be a gradual increase in intensity with the amount of amyloid deposition. However, in the spleen, amyloid deposits did not react with anti-Ub antibody in any phase of amyloid induction. These results suggest that Apo E and Ub are not always associated with the process of amyloid deposition and may appear in a deposit after the deposition.     

Complete clinical remission and subsequent relapse of bronchiectasis-related (AA) amyloid induced nephrotic syndrome

Systemic amyloidosis normally has a dismal prognosis. However, there are several case reports of protracted survival, usually as a response to measures designed to retard the further deposition of amyloid fibrils. In AA amyloid, most commonly associated with inflammatory rheumatological, bowel, and chest diseases, such interventions have had some success, but the dramatic response of complete resolution of nephrotic syndrome as a result of the regular institution of postural chest drainage and antibiotic therapy, in the clinical context of bronchiectasis, has been previously reported only once. In both of our cases, after protracted remission, such therapy was abandoned by the patients, leading both to recurrence of nephrotic syndrome and also eventually to end-stage renal failure requiring dialysis.     

Systemic amyloidosis presenting as cholestatic jaundice

We present a case of a 68 year old man with general deterioration and recent onset of jaundice that was admitted for clinical evaluation. Previous records were: treated bone tuberculosis, hypertrophic myocardiopathy and ischemic cardiopathy. Physical examination showed liver enlargement without evidence of chronic liver disease. Laboratory studies and other explorations such as abdominal ultrasound, CAT and ERCP did not leed to an objective diagnosis. Therefore, a liver biopsy was performed, showing liver amyloidosis AA type with amyloid deposits in portal spaces. The patient died three months later. The rarity of this clinical presentation is discussed and its poor prognosis outlined. Some peculiarities of liver deposits are reviewed.     

Amyloid and non-amyloid carpal tunnel syndrome in patients receiving chronic renal dialysis

OBJECTIVE: To determine the prevalence of amyloid deposits among patients with carpal tunnel syndrome (CTS) receiving dialysis, and to investigate the factors associated with amyloid and non-amyloid CTS. METHODS: Subjects for this prospective study were dialysis patients who underwent surgery for CTS in the same surgical unit between 1989 and 1997. CTS was diagnosed from clinical and electromyographic (EMG) findings. Systematic standard radiographs and laboratory data were also obtained. Surgical investigations included systematic macroscopic examination and biopsy of the epineurium, flexor retinaculum, synovium, and flexor tendon sheaths. Samples were stained for amyloid and examined by plain and polarized light microscopy, immunohistochemistry, and electron microscopy. RESULTS: Forty-one samples from 30 patients (11 bilateral cases) were examined. Amyloid deposits were found in 26 samples from 18 patients (7 M, 11 F). Fifteen samples from 12 patients (3 M, 9 F) showed no amyloid deposits. Amyloid CTS was statistically significantly associated with arthralgia and longterm dialysis [mean 13.3 (range 5.5-23) vs 7.5 yrs (range 3 mo-14 yrs)] in non-amyloid CTS. Flexor tenosynovitis and carpal bone erosion occurred more frequently in amyloid CTS. There were no statistically significant differences between the 2 groups in clinical, laboratory or EMG findings, type of dialysis membrane, or frequency of ipsilateral fistula. Only amyloid CTS was recurrent. CONCLUSION: Amyloid deposits were confirmed microscopically in 63.4% of patients. The relatively large number of cases of non-amyloid CTS without signs of dialysis associated arthropathy suggests that CTS is not a satisfactory criterion for diagnosis of dialysis arthropathy or beta2-microglobulin amyloidosis unless the presence of amyloid has been confirmed or duration of dialysis treatment has been at least 15 years.     

Localized amyloidosis of the seminal vesicle. Possible association with hormonally treated prostatic adenocarcinoma

OBJECTIVE: Localized seminal vesicle amyloidosis is an unusual finding in surgical pathology material. Previous studies have demonstrated that the amyloid is directly produced by the seminal vesicle epithelial cells. We investigated the possible association of seminal vesicle amyloid in patients hormonally treated for prostate carcinoma. METHODS: Cases were collected from over 200 prostate needle biopsies, seminal vesicle biopsies, and prostatectomy specimens from the surgical pathology files at The Mount Sinai Hospital, New York, NY. None of the patients with seminal vesicle amyloidosis had a chronic inflammatory disorder, serum or urine protein abnormalities, or other identifiable masses. RESULTS: Six cases of localized seminal vesicle amyloidosis were found in the surgical pathology material examined. Five of the six cases had prostatic carcinoma, and one case was seen in a biopsy for benign prostatic hyperplasia. Four of the five carcinoma cases had prior hormonal treatment (luteinizing hormone-releasing hormone agonist with an antiandrogen agent, and one patient, in addition, had received radiotherapy). The amyloid deposits were limited to the seminal vesicle lamina propria without involvement of vascular walls. The amyloid reacted with Congo red staining that was sensitive to potassium permanganate. Immunohistochemically, all cases were negative for AA amyloid, beta 2-microglobulin, and kappa and lambda light chains. CONCLUSION: We raise the possibility that in some instances, prior hormonal therapy may act as a seminal vesicle epithelial stimulant for the elaboration of this protein.     

Diagnostic criteria of limited adenocarcinoma of the prostate on needle biopsy

Dialysis amyloidosis is one of the most incapacitating complications of long-term dialysis treatment. Quantitative assessment of amyloid deposition using radiolabelled tracers has been recently proposed but convincing evidence of its validity in uraemic patients remains to be provided. We studied the plasma kinetics of i.v. administered 125I-labelled serum amyloid P component (125I-SAP) in 20 chronic haemodialysis patients compared with those of nine healthy volunteers and three non-dialysed patients with systemic amyloidosis. Plasma clearance of the tracer was abnormal in 17 of 20 dialysis patients in whom plasma radioactivity declined in a bi-exponential mode, in contrast to the single-exponential slope observed in all healthy controls. 125I-SAP plasma half-life of the second component, probably reflecting metabolic clearance, was significantly prolonged in these dialysis patients compared with the healthy controls (35.3 versus 24.6 h, P < 0.001). Among the long-term haemodialysis patients the calculated extravascular distribution of 125I-SAP was significantly greater in those with severe arthropathy than in asymptomatic patients. These findings demonstrate for the first time that SAP clearance is disturbed in haemodialysis patients due to both failing renal elimination and retention in extravascular sites. The extravascular diffusion is greatly enhanced in patients with clinical evidence of amyloidosis. Therefore the study of plasma 125I-SAP kinetics promises to be a valuable tool to quantitate the extent of amyloidosis.     

Primary localization amyloidosis of the sublingual gland

We here in present a very rare case of primary localized amyloidosis with amyloid A protein of the sublingual gland. It presented a tumorous appearance on the left oral floor. Pretreatment with potassium premanganate made biopsy specimens unstained by Congo red. Immunohistochemical staining for AA protein was positive. Systemic amyloidosis was ruled out based on clinical and laboratory examinations. The gastric and the labial salivary glands biopsy showed no amyloid deposits. As far as we know, this is the first case of primary localized amyloidosis with amyloid A protein of the oral cavity, and tumor-formed amyloidosis of the sublingual gland.