Pulmonary mycobacterial spindle cell pseudotumor in a lung transplant patient: progression without therapy and response to therapy

Mycobacterial spindle cell pseudotumor (MSP) represents a rare, non-malignant, mass-forming reaction to various mycobacterial infections, typically occurring in immunocompromised patients. It is characterized by the proliferation of spindle-shaped fibrohistiocytic cells without the formation of epithelioid granulomas. Without staining for acid-fast bacilli, histological distinction from other spindle cell lesions, including malignancy, can be difficult. Most of the MSP cases reported in the literature have involved lymph nodes, skin, spleen, or bone marrow, but rarely involve the lung. MSP predominately occurs in patients who are immunosuppressed. We present a patient with MSP of the transplanted lung caused by non-tuberculous mycobacteria, in whom both the natural course of the untreated pseudotumor as well as the response to antimycobacterial treatments were observed.

The thin-cap fibroatheroma: a type of vulnerable plaque: the major precursor lesion to acute coronary syndromes

While the concept of plaque 'vulnerability' implies a propensity towards thrombosis, the term vulnerable was originally intended to provide a morphologic description consistent with plaques that are prone to rupture. It is now known that the etiology of coronary thrombi is diverse and can arise from entities of plaque erosion or calcified nodules. These findings have prompted the search for more definitive terminology to describe precursor lesions associated with rupture, now referred to as thin-cap fibroatheromas. This review focuses on the thin-cap fibroatheroma, as a specific cause of acute coronary syndromes. To put these issues into current perspective, we need to revisit some of the older literature describing plaque morphology in stable and unstable angina, acute myocardial infarction, and sudden coronary death. The morphology, frequency, and precise location of these thin-cap fibroatheromas are further discussed in detail. Potential mechanisms of fibrous cap thinning are also addressed, in particular emerging data, which suggests the role of cell death "apoptosis" in cap atrophy.

Sudden cardiac death

The rate of cardiac deaths that are sudden is approximately 50%, and decreases with age. The causes of sudden cardiac death are diverse, and are a function of age. In children and adolescents, coronary anomalies, hypertrophic cardiomyopathy and myocarditis are frequent substrates for lethal arrhythmias; in adults, coronary atherosclerosis and acquired forms of cardiomyopathy are the most common findings at autopsies of sudden cardiac death. This review focuses on coronary causes of sudden cardiac death, especially congenital coronary artery anomalies, which result in sudden death almost exclusively in adults younger than age 35, and coronary thrombosis. The most lethal coronary artery anomaly is the left coronary artery arising from the right sinus of Valsalva; this anomaly often results in fatal arrhythmias, often with exercise. The right coronary artery arising from the left sinus of Valsalva may also be lethal in adolescents and young adults, but, unlike the anomalous left, is more often an incidental finding at autopsy. Approximately 60% of sudden coronary death is caused by coronary thrombosis, the rest die with severe coronary disease in the absence of thrombosis. The two major substrates of coronary thrombosis are plaque rupture and plaque erosion, and are not only different pathologically, but are seen in patients with divergent risk factor profiles. Plaque rupture is the most common cause of fatal coronary thrombus, and is characterized by necrotic core with a thin fibrous cap, infiltrated by macrophages. The factors that result in plaque instability and rupture are largely unknown, and are under intense scrutiny; morphologic studies have identified serum lipid abnormalities as a key risk factor in the development of plaque rupture. Plaque erosion, in contrast to plaque rupture, is seen in younger men and women, is not associated with lipid abnormalities, and does not result from exposure of the lipid core to the lumen. The heterogeneity of the atherosclerotic plaque and the diverse mechanics of plaque progression and thrombosis have only been relatively recently explored, and are largely elucidated by autopsy studies of victims of sudden coronary death.

Pathophysiology of calcium deposition in coronary arteries

BACKGROUND AND MORPHOLOGIC STUDIES: Because coronary artery calcification correlates highly with plaque burden, it is an excellent disease marker for atherosclerosis. However, it is not a sensitive indicator of disease activity, and does not predict luminal compromise because of compensatory remodeling. In addition, most data do not support the concept that plaque calcification is related to plaque instability. Plaques demonstrating acute rupture usually show mild or moderate calcification, and biophysical models do not predict that calcium should result in an increased propensity to rupture. This review outlines morphologic studies relating calcification to risk factors and coronary plaque morphology.

A primary cardiac sarcoma with unusual histology and clinical course

A left atrial tumor, in which radical resection was impossible, demonstrated two processes: An inflammatory pseudotumor and cellular atypia suggestive of a sarcoma. Immunohistochemistry (proliferating cell nuclear antigen [PCNA], MIB-1 [Ki-67 antibody], bcl-2 positive; p53 negative, focal loss of nm23) was supportive for a malignant tumor. Despite no further therapy because of uncertainty in tumor classification, the patient remained in remission for 28 months. Thereafter, spine metastases and local regrowth were found, and the patient died 15 months later, after temporary remission by radiotherapy. This case stresses the impact immunohistochemistry may have on diagnosis of malignancy and the difficulty in predicting the biological behavior of cardiac sarcomas.

Coronary atherosclerosis in unheralded sudden coronary death under age 50: histo-pathologic comparison with 'healthy' subjects dying out of hospital

AIM

sudden coronary death (SCD) in older individuals is generally associated with extensive coronary atherosclerosis, although it may be the first manifestation of ischaemic heart disease. In younger age-groups, SCD may occur in the presence of less severe disease. We sought to (1) examine the extent of coronary atherosclerosis in young victims of SCD compared with age- and sex-matched controls, (2) analyse the composition of atherosclerotic plaques in these patients, (3) identify the predominant mechanism of SCD, and (4) evaluate the possibility of detecting this mechanism on the basis of morphologic plaque features, in particular presence and amount of lipid accumulation and calcific deposits.

METHODS AND RESULTS

coronary arteries were obtained at autopsy from 28 victims of SCD under age 50 with no prior clinical manifestation of ischaemic heart disease (IHD) and no myocardial scar formation and from 16 age- and sex-matched subjects dying of noncardiac causes out of hospital. Sections of all available major coronary arteries were cut in 5-mm intervals to yield a total of 1357 histologic sections, which were analysed using digitised planimetry. Victims of SCD had significantly more major coronary arteries per subject with luminal area narrowing > or = 75% than controls (on average, 2.1 vs. 0.2). Plaque area per histologic section was 5.1 +/- 2.1 mm(2) in SCD cases and 2.0 +/- 0.9 mm(2) in controls (P < 0.001). The major constituent of all plaques was fibrous tissue. Lipid core area per section was 0.49 +/- 0.59 mm(2) in SCD cases and 0.004 +/- 0.01 mm(2) in controls (P < 0.001), and calcified plaque area was 0.18 +/- 0.19 mm(2) in SCD cases and 0.02 +/- 0.05 mm(2) in controls (P < 0.001), both defining significant differences between SCD cases and controls. Arterial thrombosis, most often with underlying plaque rupture was the mechanism of SCD in > 80% of the cases. Considering histologic sections with > or = 50 and with > or = 75% area stenosis, plaque rupture was independently predicted by lipid core area. Calcific deposits were a frequent feature of plaque rupture but were only associated with it in univariate analysis.

CONCLUSIONS

the extent and severity of coronary atherosclerosis in young victims of SCD as the first manifestation of IHD was substantially greater than in age-and sex-matched controls and comparable with that previously reported in SCD cases with a broader age range. Lipid core and calcified plaque areas provided for excellent separation between the two groups, which may have implications for identifying persons at increased risk for SCD by non invasive visualisation and assessment of the coronary arteries.

The impact of calcification on the biomechanical stability of atherosclerotic plaques

BACKGROUND

Increased biomechanical stresses in the fibrous cap of atherosclerotic plaques contribute to plaque rupture and, consequently, to thrombosis and myocardial infarction. Thin fibrous caps and large lipid pools are important determinants of increased plaque stresses. Although coronary calcification is associated with worse cardiovascular prognosis, the relationship between atheroma calcification and stresses is incompletely described.

METHODS AND RESULTS

To test the hypothesis that calcification impacts biomechanical stresses in human atherosclerotic lesions, we studied 20 human coronary lesions with techniques that have previously been shown to predict plaque rupture locations accurately. Ten ruptured and 10 stable lesions derived from post mortem coronary arteries were studied using large-strain finite element analysis. Maximum stress was not correlated with percentage of calcification, but it was positively correlated with the percentage of lipid (P:=0.024). When calcification was eliminated and replaced with fibrous plaque, stress changed insignificantly; the median increase in stress for all specimens was 0.1% (range, 0% to 8%; P:=0.85). In contrast, stress decreased by a median of 26% (range, 1% to 78%; P:=0.02) when lipid was replaced with fibrous plaque.

CONCLUSIONS

Calcification does not increase fibrous cap stress in typical ruptured or stable human coronary atherosclerotic lesions. In contrast to lipid pools, which dramatically increase stresses, calcification does not seem to decrease the mechanical stability of the coronary atheroma.

Healed plaque ruptures and sudden coronary death: evidence that subclinical rupture has a role in plaque progression

BACKGROUND

Subclinical episodes of plaque disruption followed by healing are considered a mechanism of increased plaque burden. Detailed pathological studies of healed ruptures, however, are lacking.

METHODS AND RESULTS

We identified acute and healed ruptures from 142 men who died of sudden coronary death and performed morphometric measurements of plaque burden, luminal stenosis, and smooth muscle cell phenotype. Healed ruptures were found in 61% of hearts and were associated with healed myocardial infarction, increased heart weight, dyslipidemia, and diabetes. Multiple healed rupture sites with layering were frequently found in segments with acute and healed rupture; the percent area luminal narrowing increased with increased numbers of healed sites of previous rupture. The underlying percent luminal narrowing for acute ruptures (mean 79+/-15%) exceeded that for healed ruptures (mean 66+/-14%, P:=0.0001), and the area within the internal elastic lamina was significantly less in healed ruptures than in acute ruptures, when segments were grouped by distance from the ostium. Healed ruptures favored the accumulation of immature smooth muscle cells at repair sites, with a cellular proliferation index of 0.40+/-0.09%, significantly higher than the index at the sites of rupture (P:=0.008).

CONCLUSIONS

These data provide evidence that silent plaque rupture is a form of wound healing that results in increased percent stenosis. Healed ruptures occur in arteries with less cross-sectional area luminal narrowing than acute ruptures and are a frequent finding in men who die suddenly with severe coronary atherosclerosis.

Localized vasculitis

The mechanisms of vasculitis are poorly understood, but involve immune-mediated destruction of vessel walls. Depending on the syndrome, there is significant variability in the size and types of vessels involved, as well as the nature of the inflammatory infiltrate. In addition, there is a wide variation from 1 patient to another in the extent of involvement throughout the vascular tree. In some forms of vasculitis that are histologically indistinguishable from systemic syndromes, the inflammatory process appears to be isolated, or localized to a single site or organ. In most such cases, especially in localized forms of necrotizing polyarteritis, the prognosis is far better than for corresponding systemic vasculitides, and progression to systemic disease is unusual even without immunosuppressive treatment. However, for other types of vasculitic syndromes, especially Wegener's granulomatosis and antineutrophil cytoplasmic autoantibody-related vasculitis, presentation as a localized process warrants immediate treatment and may herald a prolonged, if relatively limited, disease. This article outlines the clinical and pathologic features of the vasculitis syndromes that may be localized at the time of diagnosis, and emphasizes which features are associated with progression to systemic disease.

Effect of menopause on plaque morphologic characteristics in coronary atherosclerosis

BACKGROUND

Coronary artery disease in women appears 10 to 15 years later than in men. To test the hypothesis that the effects of estrogen may manifest themselves as histologic differences in coronary plaques, we examined the hearts of premenopausal and postmenopausal women who died suddenly from coronary artery disease.

METHODS

We studied 51 cases of sudden coronary death and 47 deaths in women who died from noncoronary causes. Coronary deaths were classified on the basis of histologic features. The number of acute plaque ruptures, healed plaque ruptures, vulnerable plaques, and acute plaque erosions were compared between groups. Postmortem values of serum total cholesterol, HDL cholesterol, and thiocyanate were measured, and menopausal status was confirmed by calculating body mass index.

RESULTS

Women older than 50 years of age were much more likely to have a ruptured plaque than were younger, premenopausal women. Plaque rupture was significantly associated with elevated total cholesterol level. In the 51 women who died of coronary disease, the mean number of vulnerable plaques increased significantly as women advanced into the postmenopausal years.

CONCLUSIONS

Our data suggest that estrogen has an anti-inflammatory effect on atherosclerotic plaques, resulting in plaque stabilization. Plaque erosion, the major substrate for thrombosis in premenopausal women, does not appear to be inhibited by estrogen. Because plaque progression may result both from repeated rupture and repeated erosion, a better understanding of the effect of estrogen on atherosclerosis may yield insights into the nature of coronary artery disease.

Primary cardiac and pericardial neoplasms: radiologic-pathologic correlation

Primary cardiac and pericardial neoplasms are rare lesions and include both benign and malignant histologic types. Myxoma is the most frequent primary cardiac neoplasm, but other benign tumors include papillary fibroelastoma, rhabdomyoma, fibroma, hemangioma, lipoma, and paraganglioma. Cardiac sarcoma represents the second most common primary cardiac neoplasm. Lymphoma can also affect the heart primarily. Pericardial tumors that affect the heart include benign teratomas and malignant mesotheliomas. Patients affected with cardiac or pericardial neoplasms often present with cardiovascular compromise or embolic phenomena and exhibit cardiomegaly at chest radiography. Benign cardiac tumors typically manifest as intracavitary, mural, or epicardial focal masses, whereas malignant tumors demonstrate invasive features and may involve the heart diffusely. Benign lesions can usually be successfully excised, but patients with malignant lesions have an extremely poor prognosis.

Coronary calcification: insights from sudden coronary death victims

We studied 108 cases of sudden coronary death at autopsy. Any calcification was present in 55% of men and women under 40 years; all hearts showed some calcification by age 50 in men, and by age 60 in women. The only risk factor independently associated with increased calcification was diabetes mellitus, in women only. The degree of calcification was greatest for acute and healed plaque ruptures, and the least for plaque erosion. Calcification in coronary atherosclerosis appears to be delayed in women, is greatest in women diabetics, and is associated with one type of plaque instability, namely plaque rupture.

A comparison of the Framingham risk index, coronary artery calcification, and culprit plaque morphology in sudden cardiac death

BACKGROUND

Neither clinical prediction models nor noninvasive imaging tests that detect coronary artery calcification identify all patients who experience acute coronary events. Variations in culprit plaque morphology may account for these inaccuracies.

METHODS AND RESULTS

We compared the 10-year Framingham risk index, histologic coronary calcification, and culprit plaque morphology in 79 consecutive adults with sudden cardiac death. There was a modest relationship between the Framingham risk index and the extent of histologic coronary calcification (r=0.35, P=0.002). Agreement in risk classification between the histologic calcification score and the Framingham risk index occurred in 50 of 79 cases (63.3%, P=0. 039). Either a focus of coronary artery calcification >/=40 micromol/L (62% of cases) or a Framingham risk index score >/= average risk for age (62% of cases) were present in 66 of 79 (83.5%) cases. Cases with plaque erosion (n=22) had significantly less coronary calcification (P=0.003) and lower Framingham risk index (P=0.001) scores than stable (n=27) or ruptured (n=30) plaques. Fourteen of 22 (63.6%) cases of plaque erosion were classified as low risk by both the Framingham risk index and the histologic calcification score.

CONCLUSIONS

The prediction of sudden cardiac death using the Framingham risk index and the measurement of coronary calcification are distinct methods of assessing risk for sudden cardiac death. Excessive reliance on either method alone will produce errors in risk classification, particularly for patients at risk of plaque erosion, but their combination may be complementary.

Anaplastic large cell lymphoma (CD 30+), T-phenotype, in the heart of an HIV-positive man

Non-Hodgkin's lymphomas described in patients with HIV-infection are most often high-grade B-cell lymphomas. Anaplastic large cell lymphoma (CD 30+) has been described in a minority of immunocompromised patients. Although sporadic reports of T-cell lymphomas associated with HIV infection are found in the literature, they have not been described to occur in the myocardium. We present a case of anaplastic large cell lymphoma (CD 30+), T-phenotype involving the heart in a 42-year-old HIV-positive patient.

Arterial remodeling in the left coronary system: the role of high-density lipoprotein cholesterol

OBJECTIVES

We sought to evaluate the plaque and patient variables related to arterial remodeling responses of early, de novo atherosclerotic lesions involving the left coronary artery.

BACKGROUND

Coronary artery remodeling is a lesion-specific process involving either enlargement or shrinkage of atherosclerotic coronary arteries. There are little histologic data available correlating plaque morphologic and patient clinical characteristics with the degree and type of arterial remodeling in early atherosclerosis.

METHODS

We studied 736 serial arterial sections from the left coronary system of 97 autopsy cases (mean age 33 +/- 11 years) by correlating the arterial remodeling response to plaque with demographic, serologic and histologic variables. Using the most proximal section as a reference, and considering the expected degree of internal elastic lamina tapering, remodeling was classified as positive (including neutral remodeling or compensatory enlargement) or negative.

RESULTS

Remodeling was classified as positive in 84.3% (compensatory in 30.6%) and negative in 15.7% of sections with an overall mean luminal stenosis of 10.4 +/- 9.9%. In the lesions with the greatest arterial cross-sectional narrowing from each case, compensatory enlargement was associated with higher high-density lipoprotein (HDL) cholesterol (59.4 +/- 27.2 mg/dl) compared with either neutral (49.3 +/- 15.5 mg/dl) or negative remodeling (30.4 +/- 5.2 mg/dl; p = 0.019). In subjects with advanced atherosclerosis (maximum American Heart Association histologic grade 5 atherosclerosis), there was a modest linear relationship between higher HDL cholesterol and the propensity for positive remodeling (r2 = 0.37; p = 0.025). On multivariate analysis, only HDL cholesterol was related to the arterial remodeling response.

CONCLUSIONS

Negative arterial remodeling occurs in early atherosclerosis. Higher HDL cholesterol may favor positive remodeling.

Plaque erosion is a major substrate for coronary thrombosis in acute myocardial infarction

OBJECTIVE

To evaluate the prevalence of plaque erosion as a substrate for coronary thrombosis.

DESIGN

Pathological study in patients with acute myocardial infarction not treated with thrombolysis or coronary interventional procedures.

PATIENTS

298 consecutive patients (189 men, mean (SD) age 66 (11) years; 109 women, 74 (8) years) dying in hospital between 1984 and 1996 from acute myocardial infarction, diagnosed by ECG changes and rise in cardiac enzymes.

MAIN OUTCOME MEASURES

Histopathological determination of plaque erosion as substrate for acute thrombosis; location and histological type of coronary thrombosis; acute and healed myocardial infarcts; ventricular rupture.

RESULTS

Acute coronary thrombi were found in 291 hearts (98%); in 74 cases (25%; 40/107 women (37.4%) and 34/184 men (18.5%); p = 0.0004), the plaque substrate for thrombosis was erosion. Healed infarcts were found in 37.5% of men v 22% of women (p = 0.01). Heart rupture was more common in women than in men (22% v 10.5%, p = 0.01). The distribution of infarcts, thrombus location, heart rupture, and healed infarcts was similar in cases of plaque rupture and plaque erosion.

CONCLUSIONS

Plaque erosion is an important substrate for coronary thrombosis in patients dying of acute myocardial infarction. Its prevalence is significantly higher in women than in men.

Plaque rupture and plaque erosion

There are multiple substrates for coronary thrombosis overlying an atherosclerotic plaque. The most common, plaque rupture, consists of an interruption of a thin fibrous cap overlying a lipid rich core. Plaque rupture is a result of macrophage infiltration and matrix degradation, is often seen in calcified plaques, and is highly associated with hypercholesterolemia. A less common substrate, plaque erosion, is not associated with elevated cholesterol and is the prime cause of coronary thrombosis in premenopausal women. The characteristic histologic features are abundant surface smooth muscle cells and proteoglycans, and a small or absent lipid rich core. The mechanisms of plaque erosion are unclear, and there are no consistent risk factors, although patients are often smokers.

Carcinoid tumors of the ampulla of Vater: a comparison with duodenal carcinoid tumors

BACKGROUND

Although ampullary carcinoid tumors (ACs) are often categorized clinically as duodenal carcinoid tumors (DCs), there are distinct clinical and pathologic differences.

METHODS

Clinical, histopathologic, and immunohistochemical features of 12 ACs were compared with those of 53 DCs that did not involve the ampulla.

RESULTS

Patients with AC were ages 28-74 years (mean, 54.9 years); 8 were males and 4 were females. Five were white and three were black; the race of four patients was not known. The size of ACs ranged from 0.2 to 5.0 cm in greatest dimension. There were no significant differences between AC patients and DC patients with respect to male predominance, race, tumor size, and mitotic rate. The insular growth pattern was more common in AC; the cribriform type was more common in DC. Four of 12 ACs contained psammoma bodies, versus none of 53 DCs (P = 0.001). The rate of metastasis was similar in patients with AC (4 of 12, 33%) compared with DC patients (14 of 53, 26%). In DC patients, involvement of the muscularis propria, a size greater than 2 cm, and mitotic activity were significantly correlated with metastatic risk. In AC patients, tumor size and mitotic activity had no correlation with metastatic potential. One AC had features of an atypical carcinoid tumor; there were none in the duodenal group. One-half of patients with AC presented with jaundice versus 7% of patients with DC (P = 0.005). Three patients (25%) with AC had von Recklinghausen disease versus 0 of 53 patients with DC (P = 0.003). Immunohistochemically, tumor cells expressed somatostatin in 67%, serotonin and cholecystokinin in 17%, insulin in 25%, and glucagon and gastrin in 0% of ACs. In contrast, 56% of DCs expressed gastrin (P < 0.001).

CONCLUSIONS

Carcinoid tumors of the ampulla differ clinically, histologically, and immunohistochemically from carcinoid tumors elsewhere in the duodenum.

Carcinoid tumors of the ampulla of Vater: a comparison with duodenal carcinoid tumors

BACKGROUND

Although ampullary carcinoid tumors (ACs) are often categorized clinically as duodenal carcinoid tumors (DCs), there are distinct clinical and pathologic differences.

METHODS

Clinical, histopathologic, and immunohistochemical features of 12 ACs were compared with those of 53 DCs that did not involve the ampulla.

RESULTS

Patients with AC were ages 28-74 years (mean, 54.9 years); 8 were males and 4 were females. Five were white and three were black; the race of four patients was not known. The size of ACs ranged from 0.2 to 5.0 cm in greatest dimension. There were no significant differences between AC patients and DC patients with respect to male predominance, race, tumor size, and mitotic rate. The insular growth pattern was more common in AC; the cribriform type was more common in DC. Four of 12 ACs contained psammoma bodies, versus none of 53 DCs (P = 0.001). The rate of metastasis was similar in patients with AC (4 of 12, 33%) compared with DC patients (14 of 53, 26%). In DC patients, involvement of the muscularis propria, a size greater than 2 cm, and mitotic activity were significantly correlated with metastatic risk. In AC patients, tumor size and mitotic activity had no correlation with metastatic potential. One AC had features of an atypical carcinoid tumor; there were none in the duodenal group. One-half of patients with AC presented with jaundice versus 7% of patients with DC (P = 0.005). Three patients (25%) with AC had von Recklinghausen disease versus 0 of 53 patients with DC (P = 0.003). Immunohistochemically, tumor cells expressed somatostatin in 67%, serotonin and cholecystokinin in 17%, insulin in 25%, and glucagon and gastrin in 0% of ACs. In contrast, 56% of DCs expressed gastrin (P < 0.001).

CONCLUSIONS

Carcinoid tumors of the ampulla differ clinically, histologically, and immunohistochemically from carcinoid tumors elsewhere in the duodenum.

Plaque rupture and sudden death related to exertion in men with coronary artery disease

CONTEXT

Exertion has been reported to acutely increase the risk of sudden coronary death, but the underlying mechanisms are unclear.

OBJECTIVE

To determine the frequency of plaque rupture in sudden deaths related to exertion compared with sudden deaths not related to exertion.

DESIGN

Autopsy survey. Coronary arteries were perfusion fixed and segments with more than 50% luminal narrowing were examined histologically. Ruptured plaques were defined as intraplaque hemorrhage with disruption of the fibrous cap and luminal thrombus. Exertion before death was determined by the investigator of the death.

SETTING

Medical examiner's office.

PATIENTS

A total of 141 men with severe coronary artery disease who died suddenly, including 116 whose deaths occurred at rest (mean [SD] age, 51 [11] years) and 25 who died during strenuous activity or emotional stress (age, 49 [9] years).

MAIN OUTCOME MEASURES

The frequency and morphology of plaque rupture was compared in men dying at rest vs those dying during exertion. Independent association of risk factors (total cholesterol, high-density lipoprotein cholesterol, glycosylated hemoglobin, cigarette smoking) in addition to acute exertion with plaque rupture were determined.

RESULTS

The mean (SD) number of vulnerable plaques in the coronary arteries of men in the exertional-death group was 1.6 (1.5) and in the at-rest group was 0.9 (1.2) (P=.03). The culprit plaque in men dying during exertion was plaque rupture in 17 (68%) of 25 vs 27 (23%) of 116 men dying at rest (P<.001). Hemorrhage into the plaque occurred in 18 (72%) of 25 men in the exertional-death group and 47 (41%) of 116 men in the rest group (P=.007). Histological evidence of acute myocardial infarction was present in 0 of 25 in the exertion group and in 15 (13%) of 116 in the rest group. Men dying during exertion had a significantly higher mean (SD) total cholesterol-high-density lipoprotein cholesterol ratio (8.2 [3.0]) than those dying at rest (6.2 [ 2.7]; P=.002), and the majority (21/25) were not conditioned. In multivariate analysis, both exertion (P=.002) and total cholesterol-high-density lipoprotein cholesterol ratio (P=.002) were associated with acute plaque rupture, independent of age and other cardiac risk factors.

CONCLUSION

In men with severe coronary artery disease, sudden death related to exertion was associated with acute plaque rupture.

Sudden death in right ventricular dysplasia with minimal gross abnormalities

Arrhythmogenic right ventricular cardiomyopathy is emerging as a relatively common cause of exercise-induced sudden death in the young. The diagnostic criteria at autopsy are, however, not fully established, leading to both over- and underdiagnosis. We report a young man and a young woman dying suddenly of right ventricular dysplasia during exercise, in whom the gross autopsy findings in the right ventricle were minimal or even absent. However, the histologic features in both right and left ventricles were typical of the disease, and consisted of fibrofatty infiltrates with typical myocyte degeneration of the right ventricle and subepicardial regions of the left ventricle. These cases illustrate that microscopic findings are diagnostic and may be present in the absence of gross findings. Marked fat replacement is not essential for the diagnosis of right ventricular dysplasia, and the right ventricle should be extensively sampled histologically in all cases of sudden unexpected death, especially those that are exercise related.

Sudden death after a cold drink: case report

We report a case of sudden cardiac death in a 12-year-old boy after rapid ingestion of a frozen slurry drink. The cause of death was determined to be a cardiac arrhythmia secondary to a previously undiagnosed cardiac rhabdomyoma with associated myocardial scarring. Ingestion of cold liquids has been associated with syncope, but not sudden cardiac death. In this case, bradycardia induced by cold-induced vasovagal reflex may have precipitated the terminal arrhythmia. Ingestion of cold liquids should be considered a potential trigger for fatal cardiac arrhythmias in patients with underlying heart disease.

Multiple coronary artery graft occlusion in a fatal case of heparin-induced thrombocytopenia

Heparin-induced thrombocytopenia (HIT) is a potentially life-threatening condition when immune-mediated platelet aggregation results in thromboembolic complications. A case is detailed of multiple saphenous vein graft thromboses and cardiac mural thrombi in a patient who died from complications of HIT.

Risk factors in the pathogenesis of coronary artery disease

In men, plaque rupture is strongly correlated with total cholesterol, and smoking is a predictor of acute thrombosis. In women younger than 50, plaque erosion correlates with smoking, whereas in women older than 50, thrombosis is secondary to plaque rupture and correlates with total cholesterol.

Intramural coronary artery dysplasia of the ventricular septum and sudden death

We report four cases of sudden unexpected death in three males and one female aged 12 to 31 years. Death occurred during exercise in three of four cases, and there was no history of sudden death or previous cardiac history in any patient. At autopsy, there was marked intramural coronary artery dysplasia of the ventricular septum, accompanied in three of the four cases by myocardial fibrosis. The arterial dysplasia was characterized by severe medial thickening with smooth muscle cell disorganization and marked luminal narrowing. There was no evidence of myofiber disarray or asymmetric septal hypertrophy to suggest hypertrophic cardiomyopathy. Other than an ostium secundum type atrial septal defect in one case, there were no associated cardiac or extracardiac lesions found at complete autopsy of these individuals. We conclude that small vessel disease of intramural coronary arteries of the ventricular septum may be an isolated finding leading to sudden cardiac death in young adults.

Hamartoma of mature cardiac myocytes

The clinical and pathological findings of three patients with hamartomas of mature cardiac myocytes resembling localized hypertrophic cardiomyopathy are presented. Hypertrophic cardiomyopathy is manifest by a poorly demarcated area of cardiac hypertrophy, microscopically demonstrating myofiber disarray and intramural coronary thickening. Localized, nonencapsulated masses of hypertrophied cardiac myocytes in locations other than the left ventricle or ventricular septum have not been reported. The clinical and pathological data of three patients with localized hamartomas were retrospectively retrieved. The patients were 9, 22, and 28 years old, respectively; none had a known family history of heart disease or cardiomyopathy. Two patients had cardiac arrhythmias: one patient died suddenly, and one patient had the Wolff-Parkinson-White syndrome. The third patient was asymptomatic. Two patients treated surgically had single masses in the right atrium and right ventricle, respectively. The patient who died suddenly had multiple discrete masses throughout the atrial and ventricular myocardium, including the left ventricular free wall. None of the three patients had septal asymmetry suggestive of hypertrophic cardiomyopathy. Histologically, there were discrete but unencapsulated nodules of marked myocyte hypertrophy with disorganization, focal scarring, and thickened intramural arteries. There was no myocyte vacuolization suggestive of cardiac rhabdomyoma. Ultrastructurally, the myocytes showed abundant and disorganized myofilaments and normal intercellular junctions. Hamartoma of mature cardiac myocytes is a previously undescribed cardiac tumor that shares some features of hypertrophic cardiomyopathy and rhabdomyoma, but is currently best considered a separate entity.

Effect of risk factors on the mechanism of acute thrombosis and sudden coronary death in women

BACKGROUND

Traditional risk factors have been linked to atherosclerotic heart disease in women. However, the effect of risk factors and menopausal status on the mechanism of sudden coronary death is unknown.

METHODS AND RESULTS

We examined 51 cases of sudden coronary death and 15 hearts from women who died of trauma. Coronary deaths were divided into four mechanisms of death: ruptured plaque with acute thrombus (n = 8), eroded plaque with acute thrombus (n = 18), stable plaque with healed infarct (n = 18), and stable plaque without infarction (n = 7). Vulnerable plaques prone to rupture were defined as those with a thin, fibrous cap infiltrated by macrophages and were quantitated in coronary deaths and control subjects. Total cholesterol (TC), HDL cholesterol, glycosylated hemoglobin, cigarette smoking, and hypertension were determined in each case. Compared with control subjects, women with plaque ruptures had elevated TC (270 +/- 55 versus 194 +/- 44 mg/dL, P = 0.002), and those with erosions were more likely to be smokers (78% versus 33%, P = 0.01). Women with stable plaque and healed infarct had elevated glycosylated hemoglobin (10.2 +/- 5.0% versus 6.4 +/- 0.4% in control subjects, P = 0.001) and were more likely to be hypertensive (50% versus 15% in control subjects, P = 0.03). By multivariate analysis, cigarette smoking was associated with plaque erosion (P = 0.03, odds ratio [OR] 21), glycoslyated hemoglobin with stable plaque and healed infarct (P = 0.03, OR 41), TC with plaque rupture (P = 0.02, OR 7), and hypertension with stable plaque with healed infarct (P = 0.02, OR 15). Seven of 8 plaque ruptures occurred in women > 50 years of age versus 3 of 18 erosions (P = 0.001). In cases of coronary death, vulnerable plaques were associated with elevated cholesterol (P = 0.002) and age > 50 years (P = 0.002), independent of other risk factors.

CONCLUSIONS

In women, traditional risk factors have distinct effects on the mechanisms of sudden coronary death, which vary by menopausal status. Effective risk factor modification may therefore differ between younger and older women and may be targeting different mechanisms of plaque instability.

Arrhythmogenic right ventricular cardiomyopathy and fatty replacement of the right ventricular myocardium: are they different diseases?

BACKGROUND

The relationship between arrhythmogenic right ventricular cardiomyopathy (ARVC) and pure fat replacement of the right ventricle is unclear.

METHODS AND RESULTS

Myocardial thickness, epicardial fat thickness, percent fibrosis, and intramyocardial fat infiltration were measured in 16 sections each from 25 hearts with typical (fibrofatty) ARVC, 7 hearts with fat replacement of the right ventricle without fibrosis (FaRV), and 18 control hearts from patients who died of noncardiac causes. Patients with fibrofatty ARVC were younger than those with FaRV (31+/-14 versus 44+/-13 years, P=.02), more likely to have a history of arrhythmias or a family history of premature sudden death (56% versus 0%, P=.01), more likely male (80% versus 29%, P=.02), and less likely to have coexisting conditions that might have predisposed to sudden death (12% versus 86%, P<.001). Fibrofatty ARVC was characterized by right ventricular myocardial thinning, fat infiltration of the anterobasal and posterolateral apical right ventricle, subepicardial left ventricular fibrofatty replacements (64%), myocyte atrophy (96%), and lymphocytic myocarditis (80%). FaRV showed normal or increased myocardial thickness, a diffuse increase in intramyocardial and epicardial fat, little inflammation, and an absence of myocardial atrophy. Intramyocardial fat was frequently seen in normal hearts, especially in the anteroapical region, but was less extensive than in fibrofatty ARVC and FaRV.

CONCLUSIONS

ARVC is a familial arrhythmogenic disease characterized by fibrofatty replacement of myocytes with scattered foci of inflammation. Fat infiltration per se is probably a different process that should not be considered synonymous with ARVC.

Causes of sudden death in young and middle-aged competitive athletes

The incidence of sudden death in athletes is low. Some pathologic conditions may predispose to sudden death during exercise in young athletes. In older individuals, exercise may trigger terminal arrhythmias in patients with severe coronary atherosclerosis. Screening programs with a history and a physical examination are recommended for high school and collegiate sports participants. For older individuals who are likely to have undetected or overt coronary heart disease and are exercising for physical fitness, caution regarding the level of activity and type of symptoms that are frequently associated with coronary disease may help prevent sudden death.

Fibromuscular dysplasia of small coronary arteries and fibrosis in the basilar ventricular septum in mitral valve prolapse

The mechanism of sudden cardiac death in patients with mitral valve prolapse is poorly understood. Twenty-four hearts from patients with mitral valve prolapse who suddenly died (mean age 34 +/- 8 years) and 16 trauma control hearts (mean age 30 +/- 7 years) were histologically studied. Dysplasia of the atrioventricular nodal artery was present in 18 of 24 hearts with mitral valve prolapse and four of 16 controls hearts (p = 0.003). The degree of luminal narrowing, as morphometrically measured, was significantly greater in hearts with mitral valve prolapse (p = 0.003). The degree of fibrosis in the base of the ventricular septum, as calculated by computerized morphometry, was greater in hearts with mitral valve prolapse (p = 0.0002) and independent of age, sex, and heart weight (p = 0.005). We conclude that arterial dysplasia in mitral valve prolapse may contribute to sudden cardiac death mediated by ventricular fibrosis.

Coronary risk factors and plaque morphology in men with coronary disease who died suddenly

BACKGROUND

Cigarette smoking and abnormal serum cholesterol concentrations are risk factors for acute coronary syndromes, but the underlying mechanisms are poorly understood. We studied whether cigarette smoking and abnormal cholesterol values may precipitate acute coronary thrombosis and sudden death resulting from either rupture of vulnerable coronary plaques or erosion of plaques.

METHODS

We examined the hearts of 113 men with coronary disease who had died suddenly and also analyzed their coronary risk factors. We found an acute coronary thrombus in each of 59 men, and severe narrowing of the coronary artery by an atherosclerotic plaque without acute thrombosis (stable plaque) in 54. Cases of acute thrombosis were divided into two groups: 41 resulting from rupture of a vulnerable plaque (a thin fibrous cap overlying a lipid-rich core), and 18 resulting from the erosion of a fibrous plaque rich in smooth-muscle cells and proteoglycans. Vulnerable plaques that had not ruptured were counted in each heart.

RESULTS

Cigarette smoking was a risk factor in 44 (75 percent) of the men with acute thrombosis, as compared with 22 (41 percent) of the men with stable plaques (P<0.001). The mean (+/-SD) ratio of serum total cholesterol to high-density lipoprotein (HDL) cholesterol was markedly elevated in the men who died of acute thrombosis with plaque rupture (mean, 8.5+/-4.0) but only mildly elevated in the men without acute thrombosis (5.5+/-2.4; P<0.001) and in the men with thrombi overlying eroded plaques (5.0+/-1.8; P<0.001). Multivariate analysis showed an association between an elevated ratio of serum total cholesterol to HDL cholesterol and the presence of vulnerable plaques (P<0.001).

CONCLUSIONS

Among men with coronary disease who die suddenly, abnormal serum cholesterol concentrations - particularly elevated ratios of total cholesterol to HDL cholesterol - predispose patients to rupture of vulnerable plaques, whereas cigarette smoking predisposes patients to acute thrombosis.

Carcinoids of the jejunum and ileum: an immunohistochemical and clinicopathologic study of 167 cases

BACKGROUND

Carcinoid tumors of the gastrointestinal tract differ in their clinical and histopathologic features, depending on the site of origin. There are few clinicopathologic studies that specifically describe jejunoileal carcinoid tumors.

METHODS

One hundred sixty-seven ileal and jejunal carcinoids were retrospectively studied with emphasis on clinical, pathologic, immunohistochemical, and prognostic features.

RESULTS

The mean age of patients at the time of presentation was 62 +/- 12 years (range, 13-93 years). Eight patients had carcinoid syndrome (5%) and 1 had Zollinger-Ellison syndrome. Twenty-six percent of tumors were multiple, and 77% were transmurally invasive; 31% had regional lymph node metastases only, and 32% had liver or mesenteric metastases. Ninety-three percent of tumors had an insular growth pattern. Serotonin was expressed in 86% of tumors (86 of 102), chromogranin in 92%, and neuron specific enolase in 95%. Twenty percent of tumors (10 of 51) expressed prostatic acid phosphatase; 96% were argyrophil, and 98% argentaffin. Of 80 cases with follow-up data (mean follow-up, 52 +/- 5 months), 21% were dead of disease, 16% were dead of other causes, 19% were alive with disease, and 44% had no evidence of disease at last follow-up. The 5-year Kaplan-Meier survival estimate for all cases was 58%. By univariate analysis, survival was negatively correlated with distant metastases at the time of surgery (P = 0.002), mitotic rate (P = 0.01), tumor multiplicity (P = 0.01), the presence of carcinoid syndrome (P = 0.02), depth of invasion (P = 0.03), and female gender (P = 0.05); by multivariate analysis, survival was negatively associated with distant metastasis (P = 0.002), carcinoid syndrome (P = 0.01), and female gender (P = 0.03).

CONCLUSIONS

Jejunoileal carcinoid tumors have a relatively high rate of transmural invasion and aggressive clinical behavior. They are usually insular and largely argentaffin, with a high rate of chromogranin and serotonin positivity. These features differentiate jejunoileal carcinoids from other gastrointestinal carcinoids.

Carcinoids of the jejunum and ileum: an immunohistochemical and clinicopathologic study of 167 cases

BACKGROUND

Carcinoid tumors of the gastrointestinal tract differ in their clinical and histopathologic features, depending on the site of origin. There are few clinicopathologic studies that specifically describe jejunoileal carcinoid tumors.

METHODS

One hundred sixty-seven ileal and jejunal carcinoids were retrospectively studied with emphasis on clinical, pathologic, immunohistochemical, and prognostic features.

RESULTS

The mean age of patients at the time of presentation was 62 +/- 12 years (range, 13-93 years). Eight patients had carcinoid syndrome (5%) and 1 had Zollinger-Ellison syndrome. Twenty-six percent of tumors were multiple, and 77% were transmurally invasive; 31% had regional lymph node metastases only, and 32% had liver or mesenteric metastases. Ninety-three percent of tumors had an insular growth pattern. Serotonin was expressed in 86% of tumors (86 of 102), chromogranin in 92%, and neuron specific enolase in 95%. Twenty percent of tumors (10 of 51) expressed prostatic acid phosphatase; 96% were argyrophil, and 98% argentaffin. Of 80 cases with follow-up data (mean follow-up, 52 +/- 5 months), 21% were dead of disease, 16% were dead of other causes, 19% were alive with disease, and 44% had no evidence of disease at last follow-up. The 5-year Kaplan-Meier survival estimate for all cases was 58%. By univariate analysis, survival was negatively correlated with distant metastases at the time of surgery (P = 0.002), mitotic rate (P = 0.01), tumor multiplicity (P = 0.01), the presence of carcinoid syndrome (P = 0.02), depth of invasion (P = 0.03), and female gender (P = 0.05); by multivariate analysis, survival was negatively associated with distant metastasis (P = 0.002), carcinoid syndrome (P = 0.01), and female gender (P = 0.03).

CONCLUSIONS

Jejunoileal carcinoid tumors have a relatively high rate of transmural invasion and aggressive clinical behavior. They are usually insular and largely argentaffin, with a high rate of chromogranin and serotonin positivity. These features differentiate jejunoileal carcinoids from other gastrointestinal carcinoids.

Infectious endocarditis and sudden unexpected death: incidence and morphology of lesions in intravenous addicts and non-drug abusers

BACKGROUND

Intravenous drug (IVD) use is a wellknown risk factor for infectious endocarditis (IE), but there are few morphologic and epidemiologic data comparing IVD-related and non-IVD-related IE in cases of sudden death.

MATERIAL AND RESULTS

Between 1992 and 1994, acute IE was diagnosed in 13 IVD users at the Office of the Chief Medical Examiner in Maryland, indicating a yearly incidence of IE-related sudden unexpected deaths of 12 per 100,000. Eleven (85%) cases of acute IE occurred on apparently previously normal valves, and there was one unicuspid valve and one infected porcine prosthesis. There were three right-sided (tricuspid) lesions (23%), nine left-sided lesions (69%), and one multivalvular lesion (8%). During the same period, there were five cases of healed IE in IVD abusers, three of which involved the tricuspid valve. The prevalence of incidental healed lesions in autopsies of IVD users was 0.2%. The healed tricuspid lesions consisted of smooth-edged defects in the valve leaflet without perforations characteristic of mitral or aortic IE. The mean age of the deceased with healed lesions was 45 +/- 6 years versus 34 +/- 10 years for those with acute endocarditis (p = 0.03). During the same time period, there were six cases of acute IE among non-drug users, indicating a yearly incidence of sudden unexpected death of 0.04 per 100,000. Acute IE occurred on congenitally malformed (n = 5) or prosthetic (n = 1) valves. There were two cases of incidental healed IE (mitral and aortic valves), indicating a prevalence of 0.02%.

CONCLUSION

IVD users are 300 times more likely to die suddenly with IE than non-IVD users, and healed lesions are 25 times more common. Healed IE of the tricuspid valve is associated with IVD abuse, and has a characteristic gross appearance that differs from healed left-sided IE.

Effect of hypertension and cardiac hypertrophy on coronary artery morphology in sudden cardiac death

BACKGROUND

Epidemiological studies have shown that hypertension and left ventricular hypertrophy (LVH) increase the risk of sudden cardiac death (SCD) in patients with severe coronary artery disease (CAD). However, autopsy studies comparing the morphological substrates for SCD in normotensives and hypertensives are lacking.

METHODS AND RESULTS

Heart weight and coronary plaque morphology were prospectively compared in SCD in 36 hypertensive and 63 normotensive individuals. The frequency of CAD was similar in hypertensives (69%, n = 25) and normotensives (73%, n = 46). In 71 hearts with CAD, acute coronary thrombi were present in 76% of normotensives versus 36% of hypertensives (P = .002), LVH was present in 64% of hypertensives versus 33% of normotensives (P = .01) and in 72% of hypertensives with one-vessel disease versus 17% of normotensives with one-vessel disease (P = .0005), and a healed or acute infarct without acute thrombus was present in 36% of hypertensives versus 9% of normotensives (P = .007). Heart weight was higher in all cases of plaque rupture (519 +/- 109 g) than eroded plaque (381 +/- 92 g, P = .0002). In contrast to hypertensives, normotensive hearts with severe CAD showed a stepwise increase in heart weight with one-, two-, and three-vessel disease (P = .01).

CONCLUSIONS

Severe CAD is present in most SCD in hypertensive and normotensive individuals, but acute thrombi are more common in normotensives. LVH is an important contributing mechanism of SCD in hypertensives, especially in cases of one-vessel disease. LVH is associated with plaque rupture and extent of disease in SCD in normotensives with severe CAD.

Giant cell myocarditis: an entity distinct from sarcoidosis characterized by multiphasic myocyte destruction by cytotoxic T cells and histiocytic giant cells

Giant cell myocarditis (GCM) is a rare, rapidly fatal myocarditis with histologic features that have some similarities to cardiac sarcoidosis (CS). The natures of the inflammatory infiltrates of GCM and CS have not been systematically compared. We retrospectively compared the immunohistochemical and light microscopic findings at autopsy in eight hearts with GCM and seven hearts with CS. The patients with GCM were six women and two men (mean age, 50 +/- 13 yr) who presented with congestive heart failure with a mean duration of 46 days until death (range, 1-180 d). We observed three histologic phases, often within a single heart. The acute phase (seven cases of eight) demonstrated an extensive infiltrate of lymphocytes and eosinophils with plentiful macrophages and macrophage-derived KP-1 positive giant cells (GCs) associated with myocytic necrosis. No granulomas were identified. A healing phase (three cases of eight) showed granulation tissue, moderate macrophagic GCs, and scattered KP-1-negative myogenic GCs. A healed phase (three cases of eight) showed dense scar with no GCs. Macrophagic GCs were present preferentially in areas of myocytic damage and were never present in epicardial fat. The majority of lymphocytes were T cells, with a predominance of CD8 cells. The seven patients with CS were men (mean age, 44 +/- 18 yr). Six patients presented with sudden cardiac death and one with congestive heart failure. The histologic patterns were similar in all seven, with scattered interstitial and epicardial (five cases of seven) granulomas composed of KP-1 positive macrophages and macrophagic GCs and T lymphocytes, which were predominantly CD4 cells. Necrosis, myogenic GCs, and significant numbers of eosinophils were absent. Dense scarring was present in five cases of seven. GCM is characterized by myocytic destruction mediated by cytotoxic T cells, macrophagic GCs, and eosinophils. In contrast, CS is an interstitial granulomatous disease without myocytic necrosis.

Primary cardiac tumors causing sudden death: a review of the literature

Sudden unexpected death accounts for 200,000-400,000 deaths each year in the United States. Although the vast majority of these fatalities are related to atherosclerotic heart disease, a small percentage (approximately 0.0025%) stem from primary cardiac neoplasms. There have been 120 cases of sudden death attributed to primary cardiac tumors in the (published) literature. Although 103 of these lesions were histologically benign (86%), their intracardiac locations precipitated conductive and hemodynamic abnormalities that resulted in sudden death. These tumors are usually easily recognized at necropsy. The most common intracardiac lesion causing sudden death, endodermal heterotopia of the atrioventricular (AV) node, however, may not be discovered unless the AV node is microscopically examined. Owing to the rarity of these neoplasms, a brief review of their salient gross and microscopic features is in order.

Lipomatous hypertrophy of the atrial septum presenting as a right atrial mass

Lipomatous hypertrophy of the atrial septum (LHAS) has been associated with cardiac arrhythmias and is defined as fatty infiltration > 2 cm thick in the atrial septum. The clinical and histologic features of surgically excised LHAS have not been previously studied. We studied 11 surgical resections of LHAS and compared them with 13 autopsy cases of LHAS and 24 control autopsy hearts. Of 11 surgical patients, eight were women: patients' mean age was 63 years, and six were described as mildly to overtly obese. Symptoms included congestive heart failure, atrial fibrillation, supraventricular tachycardia, palpitations, syncope, and incidental mass found at surgery. Imagining studies typically revealed a right atrial mass with a mean size of 6 cm (range, 2.5-10 cm). Multivacuolated fat was more extensive in surgical (p = 0.005) and autopsy (p = 0.009) cases of LHAS than in control hearts. Atypical, hypertrophied myocytes were presented in 72% of cases of LHAS compared with 8% of controls (p = 0.0003). In autopsy hearts, histologically abundant multivacuolated fat, heart weight, and body size were independently associated with increased atrial septal thickness. LHAS can be surgically excised, it has a distinctive histologic appearance marked by the presence of abundant multivacuolated fat and hypertrophied myocytes, and it is associated with increased body and cardiac mass.

Effect of age, race, body surface area, heart weight and atherosclerosis on coronary artery dimensions in young males

Compensatory arterial enlargement in response to atherosclerosis has been demonstrated for the left main coronary artery. Only limited data is available on the interaction of patient characteristics and atherosclerosis with coronary artery dimensions. The purpose of the present study was to evaluate the influence of age, race, body habitus, heart weight and atherosclerosis on coronary artery dimensions of young males. Hearts from 137 young men (age 32 +/- 8 years; 78 black, 59 white) with unnatural deaths (homicide, suicide, accident, drug overdose) were perfusion-fixed, and histologic sections were obtained from the left main, proximal left anterior descending and left circumflex coronary arteries. Computerized planimetry was performed on Movat stained sections. Multiple regression analysis was used to evaluate the relative contribution of plaque size, age, race, heart weight and body surface area on coronary dimensions and compensatory enlargement in response to atherosclerosis. In the left anterior descending and left main coronary arteries, black race, body surface area and age were independent predictors of increased lumen area. In the left circumflex, age was a predictor of lumen area. Plaque area, black race and body surface area independently predicted increased area enclosed by the internal elastic lamina area. There was compensatory enlargement of internal elastic lamina with increasing plaque size in both races in the three arteries, but the percent luminal stenosis was greater in whites due to smaller artery size. Luminal narrowing did not develop until plaques occupied 30% of internal elastic lamina area. Among a population of young men with non-cardiac deaths, blacks have larger lumen and area enclosed by internal elastic lamina than whites. Age and body surface area are major determinants of lumen areas, and compensatory arterial enlargement was seen in all examined arteries in the present study.

Lymphoid changes of the nasopharyngeal and palatine tonsils that are indicative of human immunodeficiency virus infection. A clinicopathologic study of 12 cases

We report 12 cases in which the histomorphologic changes of the nasopharyngeal tonsils (adenoids) or palatine tonsils suggest infection with the human immunodeficiency virus (HIV). The patients included 10 men and two women, aged 20 to 42 years (median, 33 years). The clinical presentation included airway obstruction, pharyngitis, fever, and a tonsillar or adenoidal mass lesion. Histologic evaluation of the excised adenoids or tonsils in 10 of the cases demonstrated a spectrum of changes including florid follicular hyperplasia, follicle lysis, attenuated mantle zone, and the presence of multinucleated giant cells (MGC). The latter characteristically localized adjacent to the surface or tonsillar crypt epithelium. Two of the 12 cases showed marked lymphoid depletion with absent germinal centers, plasmacytosis, and stromal vascular proliferation. Immunohistochemical evaluation for HIV p24 core protein showed reactivity in 10 of 12 cases localized to follicular dendritic cell network (FDC), the MGC, scattered interfollicular lymphoid cells, and cells identified within the surface or crypt epithelium. Localization of viral RNA by in situ hybridization paralleled the HIV p24 immunohistochemical findings. Additional significant findings included the presence of both CD-68 and S-100 protein in the MGC and the presence of S-100 protein in dendritic cells. Other than HIV, no microorganisms were identified. At the time of presentation, eight patients were not known to be a risk for HIV infection, nor were they known to be HIV infected or suffering from AIDS. In these patients, HIV infection was suspected on the basis of the histologic changes seen in the resected tonsillar and adenoidal tissue. Serologic evaluation (by enzyme-linked immunosorbent assay), confirmed the presence of HIV infection. Our findings suggest the possibility of HIV dissemination through the upper aero-digestive tract mucosa via target cells, such as intraepithelial dendritic cells, submucosal macrophages, and T-lymphocytes. Subsequent presentation of viral antigens to the tonsillar and adenoidal lymphoid tissues results in enlargement of these structures that clinically may simulate a neoplastic proliferation but causes histomorphologic changes that are highly suspicious for HIV infection even in asymptomatic HIV-positive patients.

Replication of HIV-1 in dendritic cell-derived syncytia at the mucosal surface of the adenoid

Human immunodeficiency virus-type 1 (HIV-1) replicates actively in infected individuals, yet cells with intracellular depots of viral protein are observed only infrequently. Many cells expressing the HIV-1 Gag protein were detected at the surface of the nasopharyngeal tonsil or adenoid. This infected mucosal surface contained T cells and dendritic cells, two cell types that together support HIV-1 replication in culture. The infected cells were multinucleated syncytia and expressed the S100 and p55 dendritic cell markers. Eleven of the 13 specimens analyzed were from donors who did not have symptoms of acquired immunodeficiency syndrome (AIDS). The interaction of dendritic cells and T cells in mucosa may support HIV-1 replication, even in subclinical stages of infection.

Coronary plaque erosion without rupture into a lipid core. A frequent cause of coronary thrombosis in sudden coronary death

BACKGROUND

Coronary thrombosis has been reported to occur most frequently in lipid-rich plaques with rupture of a thin fibrous cap and contact of the thrombus with a pool of extracellular lipid. However, the frequency of coronary artery thrombosis with or without fibrous cap rupture in sudden coronary death is unknown. In this study, we compared the incidence and morphological characteristics of coronary thrombosis associated with plaque rupture versus thrombosis in eroded plaques without rupture.

METHODS AND RESULTS

Fifty consecutive cases of sudden death due to coronary artery thrombosis were studied by histology and immunohistochemistry. Plaque rupture of a fibrous cap with communication of the thrombus with a lipid pool was identified in 28 cases. Thrombi without rupture were present in 22 cases, all of which had superficial erosion of a proteoglycan-rich plaque. The mean age at death was 53 +/- 10 years in plaque rupture cases versus 44 +/- 7 years in eroded plaques without rupture (P < .02). In the plaque-rupture group, 5 of 28 (18%) were women versus 11 of 22 (50%) with eroded plaques (P = .03). The mean percent luminal area stenosis was 78 +/- 12% in plaque rupture and 70 +/- 11% in superficial erosion (P < .03). Plaque calcification was present in 69% of ruptures versus 23% of erosions (P < .002). In plaque ruptures, the fibrous cap was infiltrated by macrophages in 100% and T cells in 75% of cases compared with 50% (P < .0001) and 32% (P < .004), respectively, in superficial erosions. Clusters of smooth muscle cells adjacent to the thrombi were present in 95% of erosions versus 33% of ruptures (P < .0001). HLA-DR expression was more often seen in macrophages and T cells in ruptures (25 of 28 cases) compared with expression in macrophages in superficial erosion arteries (8 of 22 cases, P = .0002).

CONCLUSIONS

Erosion of proteoglycan-rich and smooth muscle cell-rich plaques lacking a superficial lipid core or plaque rupture is a frequent finding in sudden death due to coronary thrombosis, comprising 44% of cases in the present study. These lesions are more often seen in younger individuals and women, have less luminal narrowing and less calcification, and less often have foci of macrophages and T cells compared with plaque ruptures.

Sudden coronary death. Frequency of active coronary lesions, inactive coronary lesions, and myocardial infarction

BACKGROUND

The reported frequency of active coronary lesions (plaque rupture and coronary thrombosis) in sudden death due to coronary artery atherosclerosis (sudden coronary death) has varied from < 20% to > 80% of cases in previous series. In hearts lacking an active coronary lesion, sudden death has usually been attributed to a healed myocardial infarction. The purpose of the present study was to determine the frequency of active and inactive coronary lesions and myocardial infarction in individuals with sudden coronary death.

METHODS AND RESULTS

The hearts of persons who died as a result of sudden coronary death underwent perfusion-fixation and postmortem angiography. An active coronary lesion was defined as a disrupted plaque, luminal fibrin/platelet thrombus, or both. We defined an inactive lesion as having a cross-sectional luminal stenosis of > or = 75% with neither plaque disruption nor luminal thrombus. Ninety hearts were examined (from 72 men and 18 women; mean age at the time of death, 51 +/- 10 years). Acute myocardial infarction was present in 19 (21% [acute myocardial infarction only in 9, both acute and healed myocardial infarction in 10]), healed myocardial infarction only in 37 (41%), and no myocardial infarction in 34 (38%). Active coronary lesions were identified in 51 (57%): acute thrombi plus disrupted plaques in 27, acute thrombi only in 21, and disrupted plaques only in 3. In hearts with acute myocardial infarction, active coronary lesions were significantly more prevalent than in hearts with only healed myocardial infarction or hearts lacking an acute or a healed myocardial infarction (89%, 46%, and 50%, respectively; P < .005). Hearts without acute or healed myocardial infarction and without active lesions were similar to hearts with active lesions with respect to heart weight and severity of epicardial coronary disease.

CONCLUSIONS

Acute changes in coronary plaque morphology (thrombus, plaque disruption, or both) were found in 57% of cases of sudden coronary death. In hearts with myocardial scars and no acute infarction, active coronary lesions were identified in 46% of cases. Neither myocardial infarction (acute or healed) nor an active coronary lesion was present in 19% of hearts.

Subvalvular left ventricular outflow tract obstruction caused by "rhinonodular" calcification

Cardiac calcification is a common problem in patients with renal failure. Calcific deposits often affect the mitral annulus, the aortic valve, and the coronary arteries. We report an atypical case of cardiac calcification obstructing the left ventricular outflow tract with minimal aortic valve calcification.