Metastasizing mixed tumor of the parotid gland: a rare tumor with unusually rapid progression in a cardiac transplant recipient.

We report the case of a 69-year-old man who had a mixed tumor (pleomorphic adenoma) removed from his parotid gland 3 years after orthotopic heart transplantation. Two years later, he presented with widely metastatic mixed tumor, which resulted in his death within 6 months. Metastatic mixed tumor is histologically identical to a benign mixed tumor, but it inexplicably metastasizes. Such tumors are rare and have not been reported to date in a transplant recipient. This case illustrates the rapid and aggressive course that malignancies can follow in an immunosuppressed population. Mixed tumors are common salivary neoplasms, so transplant recipients should be carefully followed after resection for evidence of metastatic spread.

Graft arteriosclerosis-induced myocardial pathology in heart transplant recipients: predictive value of endomyocardial biopsy.

BACKGROUND: Ischemic myocardial pathology resulting from graft arteriosclerosis (GA) includes subendocardial myocyte vacuolization (SEMV), indicative of sublethal ischemic injury, and coagulative myocyte necrosis, acute and healing (CMN), indicative of infarction. METHODS: To assess the sensitivity and specificity of myocardial pathology resulting from GA in endomyocardial biopsy specimens, we correlated SEMV and CMN in the final three biopsy specimens (mean interval from last biopsy to death 23 +/- 20 days) with autopsy findings from 30 heart transplant recipients who survived more than 3 months and died of GA (n = 16) or of other causes (n = 14). The two groups were similar in other parameters. RESULTS: Myocardial ischemic injury was present at autopsy in all 16 patients with GA with the following distribution: SEMV (n = 13) nine right ventricle (RV) and left ventricle (LV), four LV only; focal CMN (n = 8) six RV and LV, two LV only; subendocardial infarct (n = 3) three LV only; and transmural infarct (n = 3) one RV, two LV. Ischemic injury was present in the RV of 11 of 16 patients with GA. Of patients without GA, one had SEMV at autopsy; none had infarcts. Ischemic myocardial pathology was present in 10 of 48 biopsy specimens from patients with GA compared with one of 41 biopsy specimens from patients without GA (p < 0.05). The specificity of SEMV on biopsy was 98%, but sensitivity was only 17%. The positive predictive value for ischemic injury was 92%, and negative predictive value was 51%. CONCLUSIONS: Myocardial pathology resulting from ischemia was present at autopsy in all patients dying of GA. Although more prevalent in the LV, 69% of patients had ischemic myocardial pathology in the RV, where it may be accessible to biopsy. Ischemic myocardial pathology in biopsy specimens is highly specific but far less sensitive, for diagnosing GA.

Enhanced lymphocyte longevity and absence of proliferation and lymphocyte apoptosis in Quilty effects of human heart allografts.

"Quilty effect" (QE) is a common and problematic observation in endomyocardial biopsy specimens from patients after cardiac transplantation. The origin, fate, and significance of QE cellular elements are unknown. Twenty-six paraffin-embedded endomyocardial biopsy specimens with QE (five QE As and twenty-one QE Bs) from twenty-two cardiac allografts were studied by immunohistochemistry for expression of Bcl-2, Fas antigen, proliferating cell nuclear antigen (PCNA), perforin, T cells (UCHL-1), macrophages (CD68), and apoptosis by in situ terminal deoxyribonucleotide transferase (TdT)-mediated dUTP nick end labeling (TUNEL). Approximately 50% of the lymphocytes present, mainly in the deeper region of 20 of 21 QE Bs and all 5 QE As, expressed Bcl-2 in a pseudo-nodular pattern surrounding high endothelial venules. Fas expression was detected in lymphocytes in 20 of 21 QE Bs and 5 QE As in a similar pattern to Bcl-2. However, endothelial cells and macrophages were Bcl-2 negative, whereas both cell types were Fas positive. Perforin was negative in nearly all lymphocytes. TUNEL staining revealed that lymphocytes in QEs did not undergo apoptosis; however, TUNEL positivity was observed in approximately 70% of endothelial cells and macrophages and certain adjacent cardiac myocytes in 20 of 21 QE Bs and 5 QE As. One large QE B with a germinal center was noted. Germinal center cells expressed PCNA intensely but were negative for Bcl-2, Fas, and TUNEL. Cells surrounding the germinal center expressed abundant Bcl-2. The following conclusions were drawn. 1) Apoptosis does not occur in lymphocytes in QE where enhanced Bcl-2 (apoptosis inhibitor) and Fas antigen (apoptosis inducer) are expressed. 2) PCNA negativity indicates that QE lymphocytes may not proliferate, and perforin negativity indicates that they may not exhibit perforin-based cytotoxicity. We propose that there may be a relationship between the longevity of lymphocytes in QE and the absence of apoptosis.

The challenge of endomyocardial biopsy interpretation in assessing cardiac allograft rejection.

The endomyocardial biopsy has long been the preferred technique for monitoring the rejection status of the cardiac allograft. During the past year, published reports have addressed important issues concerning the endomyocardial biopsy, including the reliability of the International Society for Heart and Lung Transplantation grading system; problem areas in posttransplantation biopsy interpretation, including grade 2 rejection and myocyte injury, Quilty lesions, and ischemic injury; the natural history of grade 2 rejection; the necessity of surveillance biopsies late in the posttransplantation course; and the efficacy of numerous noninvasive techniques in diagnosing or predicting rejection. No technique developed to date has been shown to have the sensitivity or specificity needed to replace the endomyocardial biopsy as a diagnostic tool. In addition, studies of endomyocardial biopsy specimens have furthered our understanding of the pathobiology of rejection and other transplant-related conditions.

Consistencies and controversies in the application of the International Society for Heart and Lung Transplantation working formulation for heart transplant biopsy specimens. Rapamycin Cardiac Rejection Treatment Trial Pathologists.

BACKGROUND: The International Society for Heart and Lung Transplantation (ISHLT) working formulation was proposed in 1990 to promote standardization in the interpretation of endomyocardial biopsy specimens obtained after heart transplantation, especially in the setting of multicenter clinical trials and for publication purposes. METHODS: To assess uniformity in interpretation, 16 pathologists experienced in posttransplant endomyocardial biopsy specimen interpretation each read independently, in randomized order, an identical series of 23 biopsy specimens representing all ISHLT grades of rejection (n = 12) and other posttransplant biopsy findings (n = 11). The pathologists represented heart transplantation centers participating in the Rapamycin Treatment Trial for Grades 2 and 3A Rejection. The index diagnosis in each case was determined by two pathology consultants who had concurred blindly on 22 of 23 (96%) biopsy specimen evaluations on their first independent reading. Discrepancies that would not affect clinical response (for example grades 0 versus 1A, 1A versus 1B, 3A versus 3B, 3B versus 4) were considered minor; those that could alter therapy were considered major. RESULTS: The 16 trial pathologists were in exact agreement with the index diagnosis in 17 (mean) +/- 3 biopsy specimens (range 10 to 22) and 20 (mean) +/- 2 biopsy specimens (range 16 to 22) if minor discrepancies were excluded. Of 368 diagnoses rendered, 265 agreed exactly with the index diagnosis and 103 differed, of which 50 were minor discrepancies. The 53 major discrepancies included grades 1A/B versus 2, 22 discrepancies; 2 versus 3A, 11; Quilty B versus 2/3A, 10; biopsy site versus 3A, 2; ischemic injury versus 3A/B, 2; Toxoplasma versus 3A, 2; posttransplantation lymphoproliferative disorder versus 3B/4, 3; and Quilty B versus posttransplantation lymphoproliferative disorder, 1. Interobserver agreement assessed by weighted kappa values was 0.67. CONCLUSIONS: First, there was agreement among the trial pathologists and the index diagnosis (excluding minor discrepancies) in 85% of biopsy specimen interpretations. Second, of 53 major discrepancies, 43 (81%) involved grades 1A/B versus 2, 2 versus 3A, and Quilty B versus 2/3A. Third, in 54% of instances in which biopsy findings other than rejection were misdiagnosed as rejection grades, the grade was sufficiently high to have adverse treatment implications. Fourth, the ISHLT working formulation provides for a high degree of diagnostic consistency among experienced observers, and concordance could be further enhanced by clarification of criteria for grade 2 rejection and Quilty B lesions.

Human transplant coronary artery disease: pathological evidence for Fas-mediated apoptotic cytotoxicity in allograft arteriopathy.

Cytotoxicity mediated by cytolytic T cells occurs exclusively through Fas- and perforin-based pathways. Such mechanisms may be important in transplant coronary artery disease (TxCAD). We studied Fas and perforin expression and apoptosis using immunohistochemical methods, in situ terminal deoxyribonucleotide transferase-mediated dUTP nick-end labeling (TUNEL), and morphologic analysis of vessels with TxCAD taken from 12 transplant patients, which we compared with vessels of 10 patients with native coronary artery disease (CAD) and vessels from 14 patients with normal coronary arteries. Fas was detected in all TxCAD specimens. Fas-positive cells were mainly endothelial cells (EC); 100% of EC and approximately one-third of T cells and macrophages were positive for Fas. Almost all TUNEL-positive cells were Fas-expressing cells. Of the T cells and macrophages that expressed Fas, 18% appeared apoptotic in the mild and moderate-to-severe TxCAD group as compared with 78% in severe TxCAD patients (p = 0.0124). By contrast, EC damage was less evident in the vessels with greater intimal disease severity: 10% in severe TxCAD versus 75% in the mild and moderate-to-severe TxCAD group (p = 0.0122). Perforin was positive in 5% of the total intimal T cells in 3 of 12 arteriopathy specimens. Fas and perforin were virtually negative in vessels taken from CAD patients. TUNEL was diffusely positive in CD68-positive foam cells in the lipid-rich core, but Fas was negative in all CAD specimens. In normal arteries, 8 of 14 specimens contained a few TUNEL-positive and Fas-positive EC and T cells. Perforin was negative. We conclude that EC damage in TxCAD seems to be brought about through a Fas-based apoptotic pathway and that CD4-positive cytolytic T cells may be the major lytic cells involved in TxCAD.

Heart transplantation-associated perioperative ischemic myocardial injury. Morphological features and clinical significance.

BACKGROUND: The frequency and clinical significance of perioperative ischemic myocardial injury (PIMI) after heart transplantation and the diagnostic features distinguishing PIMI from rejection are not well defined. METHODS AND RESULTS: We evaluated PIMI in the first four weekly endomyocardial biopsies and/or autopsy myocardium from 140 consecutive orthotopic heart transplantation recipients (1984 to 1991) by grading the severity of coagulative myocyte necrosis (CMN) as absent, 0; mild-focal, 1; moderate-multifocal, 2; or severe-confluent, 3, and determining the evolution of morphological features of its healing. CMN (often with contraction bands) was noted in 124 patients (89%); 24 patients (17%) had grade 3 CMN, of which 4 died within 30 days of transplantation. Nevertheless, at 1 year after surgery, survival was similar in patients with and without severe injury. Increased cold ischemic time but neither donor age nor intensity of inotropic support correlated with more severe early ischemic injury. PIMI inflammation was characterized by a predominantly polymorphonuclear/histiocytic infiltrate that contained lymphocytes and plasma cells, expanding the interstitium but not encroaching upon and separable from adjacent viable myocytes. Histological features of PIMI developed and resolved more slowly than those of typical myocardial infarct necrosis in nonimmunosuppressed patients; at 4 weeks, CMN persisted in 20% of patients and residual healing in nearly half. Diagnostic rejection was observed concurrently with PIMI in 54 of 533 biopsies (10%). CONCLUSIONS: Diagnosed by conventional histological criteria, PIMI is prevalent early after heart transplantation and has a protracted healing phase that can mimic or coexist with rejection. Extensive PIMI has deleterious impact on short-term survival, but the long-term impact of PIMI remains to be established.

Natural history of focal moderate cardiac allograft rejection. Is treatment warranted?

BACKGROUND: The rate of progression and potential long-term consequences of isolated foci of moderate acute rejection (FMR) on endomyocardial biopsy (EMB) have not been defined; therefore, whether FMR necessitates augmented immunosuppression remains controversial. METHODS AND RESULTS: At our institution, recipients with EMBs having FMR, defined as one or two isolated foci of cellular infiltrates with associated myocyte damage (International Society for Heart and Lung Transplantation [ISHLT] grade 2 and a subset of grade 3A), do not routinely receive intensified immunosuppression. Accordingly, to determine the outcome of untreated FMR, we reviewed 4398 EMBs (mean, 4.4 samples each) obtained after orthotopic heart transplantation in 208 consecutive recipients maintained on triple immunosuppressive therapy. The incidence of progression versus resolution of FMR, the time interval after transplantation when FMR was detected, and the relation of untreated FMR to recipient survival were analyzed. FMR categorized as one (n = 312) or two (n = 89) foci was present in 401 EMBs (9% of total) obtained 10 days to 7.5 years after transplantation from 149 recipients (72%). EMBs with FMR resolved without treatment in 341 of 401 (85%), and only 60 of 401 (15%) progressed to higher grade rejection. EMBs that progressed occurred 7.5 +/- 7.9 months (mean +/- SD) after transplantation compared with 14.0 +/- 16.5 months after transplantation for those that resolved (P < .005). Of the 60 EMBs that progressed, 55% occurred within the first 6 months, 78% within the first year, and 97% within the first 2 years after transplantation. EMBs with two foci of FMR were no more likely to progress than those with one focus. Thirty-nine recipients experienced one (n = 25), two (n = 9), three (n = 3), or four (n = 2) episodes of FMR that progressed. One or more episodes of FMR that did not progress occurred in 110 recipients. By Kaplan-Meier analysis, survival at 1 and 5 years was similar in recipients with and those without FMR progression. CONCLUSIONS: First, untreated FMR consisting of either one or two foci has a low rate of progression. Second, progression of FMR decreases with increasing postoperative interval and becomes rare after 2 years. Last, FMR progression did not identify recipients with decreased survival.

Immediate evaluation of endomyocardial biopsies for clinically suspected rejection after heart transplantation.

BACKGROUND: Acute rejection may be suspected in heart transplant recipients in the setting of new onset of clinical symptoms or alterations in cardiac function. Immediate diagnosis may be obtained by performing a frozen section on endomyocardial biopsy (EMB) specimens. However, little is known about the indications for, and the diagnostic reliability of, this procedure. METHODS AND RESULTS: EMBs with frozen section (n = 98) from 65 of 214 consecutive orthotopic heart transplant recipients were reviewed and divided into early (< or = 45 days; n = 47) and late (> 45 days; n = 51) posttransplant periods. Frozen section diagnoses (means = 1.5 EMB samples) were compared with corresponding permanent section diagnoses (means = 4.4 EMB samples), and clinical indications were analyzed. Comparison of frozen and permanent section interpretation revealed concordant pathological processes-rejection (n = 31) versus no rejection (n = 37) versus ischemic injury (n = 20)-in 88 of 98 (90%) cases. Discordant pathological processes on frozen versus permanent section in 10 of 98 (10%) cases could be attributed to ischemic injury (n = 5), sampling (n = 4), and infection (n = 1). In the 92 cases with defined clinical indications, the indication and number of EMBs positive for rejection early and late after transplantation were arrhythmia: 2 of 12 early, 4 of 10 late; congestive heart failure: 1 of 2 early, 5 of 12 late; fever: 0 of 2 early, 1 of 4 late; echo abnormality: 0 of 5 early, 0 of 1 late; syncope: 1 of 5 early, 0 of 1 late; hypotension: 1 of 3 early, 1 of 2 late; noncompliance: 0 of 0 early, 4 of 5 late; more than one of the above: 3 of 7 early, 2 of 5 late; other: 1 of 7 early, 1 of 9 late; total: 9 of 43 early, 18 of 49 late. CONCLUSIONS: Frozen section on EMB specimens accurately reflected the permanent section diagnosis in 90% of cases. No specific clinical indication predicted EMB rejection positivity with high sensitivity in either the early or late posttransplant periods.

Endocardial infiltrates in the transplanted heart: clinical significance emerging from the analysis of 5026 endomyocardial biopsy specimens.

UNLABELLED: To further elucidate the significance of endocardial infiltrates in heart transplant patients, the presence, frequency, and type of endocardial infiltrates were evaluated in 5026 endomyocardial biopsy specimens obtained from 200 heart transplant patients 0 to 75 months after heart transplantation. The relationship of endocardial infiltrates to immunologic, clinical, and demographic variables was then explored. Endocardial infiltrates were detected in 557 endomyocardial biopsy specimens (11%) from 117 heart transplant patients (58%) at 6.3 +/- 9.4 months (mean +/- SD; range, 0 to 49 months) after heart transplantation. Heart transplant patients with endocardial infiltrates were younger (p = 0.03), had a greater incidence of idiopathic dilated cardiomyopathy before heart transplantation (p = 0.05), and included a greater percentage of females (p < 0.05). Both total and treated rejection rates were significantly higher in patients with endocardial infiltrates versus those without endocardial infiltrates (p = 0.0001). Rejection on the subsequent endomyocardial biopsies was more often present in endocardial biopsy specimens with endocardial infiltrates than in those without endocardial infiltrates, both in the presence (37% versus 24%; p < 0.001) and absence (33% versus 19%; p < 0.0001) of concomitant findings of rejection. No association was identified between endocardial infiltrates and posttransplantation lymphoproliferative disorder, cytomegalovirus infection, Epstein-Barr virus infection, or cardiac allograft vasculopathy. Multivariate regression analysis confirmed that the occurrence of endocardial infiltrates is associated with rejection when adjustment is made for patient's age, gender, heart disease before transplantation, follow-up time, and number of endomyocardial biopsies after heart transplantation (p = 0.0001). CONCLUSIONS: (1) Endocardial infiltrates may occur with or without associated endomyocardial biopsy findings of rejection.(ABSTRACT TRUNCATED AT 250 WORDS)

Endomyocardial biopsy findings after photopheresis treatment of cardiac transplant rejection.

Photopheresis is a potential therapy for allograft rejection in which reinfusion of mononuclear cells exposed to ultraviolet-A irradiation after pretreatment with 8-methoxypsoralen may initiate immunosuppressive responses. Endomyocardial biopsies (EMBs) of cardiac transplant recipients with moderate acute rejection (IHSLT grades 2 and 3) treated with photopheresis (7 patients/9 treatments) and followed for six months or more were evaluated and compared with biopsies of patients treated with corticosteroids (7 patients/8 treatments) and followed for a similar time period. The first posttreatment EMB showed improvement in 100% of corticosteroid-treated patients, compared with 56% of photopheresis-treated patients (p < 0.005). Interstitial infiltrates of >90% T-lymphocytes were present in a greater percentage of photopheresis-treated patients than in corticosteroid-treated patients on the first five posttreatment EMBs (p < 0.005) as follows: EMB 1, 90% vs. 25%; EMB 2, 90% vs. 25%; EMB 3, 78% vs. 0%; EMB 4, 56% vs. 0%, EMB 5, 56% vs. 0%. Postphotopheresis EMBs also showed giant cell reaction in 1 patient and extensive band-like infiltrates in 3 patients. Our results suggest that interstitial T-cell infiltrates are more prevalent and persist longer after photopheresis than after corticosteroid treatment of heart allograft rejection. Whether these T-lymphocytes are alloreactive or mediate immunosuppressive signals is unknown. The use of new immunosuppressive therapies may modify endomyocardial biopsy findings, requiring adjustment of the diagnostic criteria for assessing and grading allograft rejection.

Giant cell myocarditis: first report of disease recurrence in the transplanted heart.

A 51-year-old female underwent heart transplantation for endomyocardial biopsy-proved giant cell myocarditis complicated by rapidly progressive congestive heart failure unresponsive to immunosuppression. Preoperatively there was no evidence of an associated extracardiac granulomatous disease. Twenty-one months after heart transplantation, giant cell myocarditis recurred in the allograft associated with sustained ventricular arrhythmias. There remained an absence of concomitant extracardiac granulomatous diseases and infections. Increased corticosteroid therapy cleared myocardial inflammation but did not abolish ventricular arrhythmias, which required pharmacologic intervention and the insertion of an Intertach II antitachycardia pacemaker. Compared with a value of 0.56 obtained 1 year after heart transplantation, left ventricular ejection fraction decreased to 0.29 at the time of diagnosis of giant cell myocarditis and remained subnormal 6 months later. Because giant cell myocarditis can recur in the allograft, the candidacy of patients with this disease for heart transplantation must be carefully assessed.

Preferential endocardial residence of B-cells in the "Quilty effect" of human heart allografts: immunohistochemical distinction from rejection.

Endocardial infiltrates (EI) are a common and often problematic observation in endomyocardial biopsy specimens (EMBs) from patients receiving cyclosporine immunosuppression following cardiac transplant. Histologic and immunohistologic findings in 23 EMBs from 19 patients and 15 autopsy or explanted allografts demonstrated EIs to be rich in B lymphocytes (871/mm2) compared to T-lymphocytes (803/mm2). Macrophages also demonstrated an endocardial preference over deeper myocardium. In contrast, T-lymphocytes outnumbered B-lymphocytes in deeper myocardium (mean 44/mm2 versus 22/mm2) especially when rejection was present. In allograft specimens, the overall number of typical nodular EIs or percent length of endocardial involvement by EI did not correlate with the presence or absence of myocardial rejection at autopsy or explant but were related to implant duration (r = +0.63, p less than 0.01) and number of previous rejection episodes. The number of thin, nondiscrete endocardial infiltrates was greater in hearts with any myocardial rejection or inflammation present. No relationship was observed between EIs present in either EMB or allografts and the cumulative or mean dose or mean serum level of cyclosporine. Thus, a distinct morphologic and immunohistologic profile distinguishes EIs from acute rejection.

Pathological findings in 2300 consecutive endomyocardial biopsies.

Endomyocardial biopsy (EMB) is a valuable diagnostic procedure for rejection surveillance in heart allograft recipients and is widely used for evaluation of native heart disease. However, the spectrum and incidence of diagnoses encountered on a heart failure/cardiac transplant service deserve clarification. Of 2300 consecutive EMBs performed during a 2.5-yr period, 79.9% had been performed for rejection surveillance in heart allograft recipients. Of these, 1281 (69.7%) were negative for rejection; 536 (29.1%) were positive (18.9% mild, 9.7% moderate, 0.5% severe); 21 (1.1%) were not interpretable due to insufficient samples. Endocardial lymphocytic infiltrates ("Quilty" effect) were present in 86 (4.7%), ischemia in 12 (0.7%), myocardial calcification in five (0.3%), foreign body giant cells in two (0.1%), valvular tissue in two (0.1%), and liver tissue in one (0.05%). Of the 20.1% of EMBs performed in patients with native heart disease, 298 (64.5%) were abnormal. A total of 239 (51.7%) had myocyte hypertrophy and/or fibrosis, while 37 (8.0%) had active or ongoing myocarditis, two of which were of the giant cell type. Other diagnoses included anthracycline cardiotoxicity in 11 (2.4%), amyloidosis in five (1.1%), hemochromatosis in two (0.4%), healed infarct in two (0.4%), scleroderma in one (0.2%), and foreign body granuloma in one (0.2%). A total of 159 (34.4%) samples had no diagnostic abnormalities; five (1.1%) were insufficient samples. As the number of EMBs performed grows, pathologists must develop expertise in the detection of morphological features pertaining to various cardiac conditions which may have similar clinical presentations.

The pathology of heart allograft rejection.

The pathologist plays an important role in the care of cardiac transplant recipients. Day-to-day management of immunosuppression is largely dependent on the diagnosis and grading of acute rejection. While noninvasive methods have been tried experimentally, the endomyocardial biopsy remains the gold standard in monitoring the rejection status of the heart allograft. The diagnosis of rejection, however, is complicated by a variety of other histologic findings, which may be procedural or processing related, due to sampling, or specifically related to transplantation. Failed allografts, whether from autopsy or explantation, provide the opportunity to study short- and long-term changes in the transplanted heart. Allograft arteriopathy, or graft atherosclerosis, is the major limiting factor in long-term recipient survival. While the morphological features of graft arteriopathy have been well described, the mechanism and factors contributing to its development remain unclear.