Adjacent Normal Muscle Research Articles

Intramuscular granular cell tumor in the sternocleidomastoid muscle: A case report and literature review.

Granular cell tumor (GCT) is a rare soft-tissue neoplasm that originates from Schwann cells. Most cases occur in the subcutaneous or submucosal regions, and intramuscular GCT is even more uncommon. Herein, we describe an atypical GCT growing in the sternocleidomastoid muscle. A 41-year-old Chinese man was admitted to our hospital for a right neck mass. In magnetic resonance images, the mass showed higher signal intensity than the adjacent normal muscle on T2-weighted images and intermediate signal intensity on T1-weighted images. Slightly enhanced and higher signal intensity was observed in the peripheral rim on contrast-enhanced fat-sat T1-weighted images, and the "stripe sign" was evident. The tumor was completely resected, and pathological examination indicated an atypical GCT. The patient tolerated the procedure well. This is a rare case report of an intramuscular GCT from diagnosis to treatment. Magnetic resonance imaging might help diagnose such tumors, and we review different magnetic resonance imaging characteristics of intramuscular GCTs at other sites.

Radiation-induced occult insufficiency fracture or bone metastasis after radiotherapy for cervical cancer? The nomogram based on quantitative apparent diffusion coefficients for discrimination

BackgroundRadiation-induced insufficiency fractures (IF) is frequently occult without fracture line, which may be mistaken as metastasis. Quantitative apparent diffusion coefficient (ADC) shows potential value for characterization of benign and malignant bone marrow diseases. The purpose of this study was to develop a nomogram based on multi-parametric ADCs in the differntiation of occult IF from bone metastasis after radiotherapy (RT) for cervical cancer.MethodsThis study included forty-seven patients with cervical cancer that showed emerging new bone lesions in RT field during the follow-up. Multi-parametric quantitative ADC values were measured for each lesion by manually setting region of interests (ROIs) on ADC maps, and the ROIs were copied to adjacent normal muscle and bone marrow. Six parameters were calculated, including ADCmean, ADCmin, ADCmax, ADCstd, ADCmean ratio (lesion/normal bone) and ADCmean ratio (lesion/muscle). For univariate analysis, receiver operating characteristic curve (ROC) analysis was performed to assess the performance. For combined diagnosis, a nomogram model was developed by using a multivariate logistic regression analysis.ResultsA total of 75 bone lesions were identified, including 48 occult IFs and 27 bone metastases. There were significant differences in the six ADC parameters between occult IFs and bone metastases (p < 0.05), the ADC ratio (lesion/ muscle) showed an optimal diagnostic efficacy, with an area under ROC (AUC) of 0.887, the sensitivity of 95.8%, the specificity of 81.5%, respectively. Regarding combined diagnosis, ADCstd and ADCmean ratio (lesion/muscle) were identified as independent factors and were selected to generate a nomogram model. The nomogram model showed a better performance, yielded an AUC of 0.92, the sensitivity of 91.7%, the specificity of 96.3%, positive predictive value (PPV) of 97.8% and negative predictive value (NPV) of 86.7%, respectively.ConclusionsMulti-parametric ADC values demonstrate potential value for differentiating occult IFs from bone metastasis, a nomogram based on the combination of ADCstd and ADCmean ratio (lesion/muscle) may provide an improved classification performance.

Identification of the molecular relationship between intravenous leiomyomatosis and uterine myoma using RNA sequencing

The purpose of this study was to explore the potential relationship between intravenous leiomyomatosis (IVL) and uterine myoma (UM) at the molecular level. RNA-sequencing was performed on IVL tumours, UM tumours, and adjacent normal uterine muscle. We compared the gene expression levels between IVL and normal uterine muscle, UM and normal uterine muscle, to identify differentially expressed genes (DEGs). Then we used Gene Ontology Enrichment Analysis to determine the functions of the DEGs and performed specimen cluster analysis. We obtained 98 DEGs between IVL and adjacent normal uterine muscle, and 61 DEGs between UM and adjacent normal uterine muscle. Functional enrichment of both IVL and UM DEGs showed that they are associated with hormone stimulus, extracellular matrix, and cell adhesion. Unsupervised clustering analysis showed that IVL and UM could not be separated completely. Among these dysregulated genes, we found that HOXA13 showed a distinct dysregulated status between IVL and UM. HOXA13 may therefore serves as a biomarker to distinguish IVL and UM. Our results showed that IVL and UM may have similar dysregulated gene networks. They may be closely related, and HOXA13 may serves as a biomarker to distinguish between IVL and UM.

PS01.041: REMOVAL OF ESOPHAGEAL HEMANGIOMA USING ENDOSCOPIC SUBMUCOSAL DISSECTION: A CASE REPORT AND REVIEW

Abstract Background Esophageal hemangiomas are rare, representing around 3% of all benign esophageal tumors. Esophagectomy or tumor enucleation has been performed to treat esophageal hemangiomas, but recently the use of endoscopic therapy, such as endoscopic mucosal resection or endoscopic injection sclerotherapy, is increasing. We describe removal of a hemangioma using endoscopic submucosal dissection. Methods A 59-year-old woman underwent endoscopic examination after an esophageal lesion was found during a general health examination. Endoscopy identified a broad-based, elevated, dark purple lesion located 17 cm distal from the incisor teeth. It measured approximately 25 mm and was rounded and soft.Endoscopic ultrasonography using a 20-MHz catheter probe and the water filling method identified a tumor 25 mm in diameter located in the mucosal and submucosal layers. The border was unclear, but the bottom of the tumor was demarcated from the adjacent normal muscle layer. Compared with the adjacent muscle layer, the tumor was hyperechoic. On the basis of these endoscopic findings, the lesion was diagnosed as a hemangioma. Because the tumor was broad-based and relatively large, we thought that polypectomy or EMR should be avoided to prevent incomplete resection and postoperative hemorrhage from the residual stump. We therefore decided that ESD was the best treatment modality for this lesion. Results Approximately 2 mL of the solution was injected into the submucosal layer at intervals, which was repeated until the mucosa became elevated. After lifting the lesion, the mucosa including the tumor was gently cut with the Flush knife using the Endocut mode. The submucosal layer was highly fibrous, so lifting the lesion was somewhat difficult. The histopathological findings showed formation of a vascular lumen with irregular dilatation just below the lamina muscularis mucosa, suggesting a cavernous hemangioma. The patient was discharged 5 days after surgery without complications. Conclusion Until quite recently, large or broad-based esophageal hemangiomas had been treated by esophagectomy or sclerotherapy. Esophagectomy is associated with a high mortality rate [19], and endoscopic sclerotherapy may cause hemorrhage upon puncture, side effects due to the infused agents, and other complications. Endoscopic resection is less invasive than sclerotherapy, and further advances in endoscopic treatment and instruments may reduce the risk of several complications. ESD has being established as a safer, less invasive therapy than esophagectomy, it is perhaps the best therapeutic option for treating large or broad-based submucosal esophageal hemangiomas. Disclosure All authors have declared no conflicts of interest.

Correlation between tumor growth and hormonal therapy with MR signal characteristics of desmoid-type fibromatosis: A preliminary study.

To evaluate the impact of hormonal therapy on MRI characteristics of desmoid-type fibromatosis on T1-weighted, T2-weighted fat-saturated and post-contrast sequences. Nineteen patients with histologically-proven desmoid-type fibromatosis were prospectively followed up on MR imaging. Eight patients underwent hormonal therapy and 11 were only surveyed. Change in tumor size during follow-up was analyzed according to RECIST. Signal intensity on T1-weighted, T2-weighted fat-saturated and T1-weighted fat-saturated post-contrast images was graded from 0 to 5 using adjacent normal muscle as reference. Findings were compared with tumor growth and treatment option. There were seven men and 12 women with a mean age of 42.2±16.4 (SD) years (range: 18 - 64 years) yielding twenty-six follow-up periods: eight of tumor progression and 18 of tumor stability/regression (some tumors exhibited more than one behavior type). Hormonal therapy was associated with tumor stability or regression (P=0.0207). There was a significant reduction in enhancement among treated patients with stable/regressing disease (P=0.049). The mean variation in enhancement grade was -1.3±1.2 in these patients. All successfully treated patients presented a reduction in enhancement. Lesions with marked low enhancement or very low signal on T2-weighted images were rare in progressing lesions (0% and 13%). Hormonal therapy has an impact on desmoid-type fibromatosis signal characteristics reducing lesion enhancement.

Myosin regulatory light chain phosphorylation is associated with leiomyosarcoma development

Leiomyosarcoma is a rare malignant smooth muscle tumor which can be very unpredictable. Myosin II is involved in many functions, including cell contraction, migration, and adhesion. The phosphorylation of myosin regulatory light chain (MLC) by myosin light chain kinase (MLCK) determines the activity of Myosin II. However, it is still unclear whether MLC phosphorylation is involved in cell proliferation in leiomyosarcoma. In this study, we aimed to explore the role of MLCK-dependent MLC phosphorylation in leiomyosarcoma development. We found that the expression of MLCK, phosphorylated MLC, and Ki67 in leiomyosarcoma was significantly higher than in leiomyoma and adjacent normal smooth muscle cells. MLCK expression was significantly correlated with phosphorylated MLC level. Kaplan-Meier survival analysis revealed that patients with high expression of MLCK or phosphorylated MLC had shorter overall survival times compared with the patients with low expression of MLCK or phosphorylated MLC. In vitro studies revealed a causative link between MLC phosphorylation and cellular proliferation as expression of phosphomimetic MLC (T19D, S20D) increased cellular proliferation as assessed by Ki67 staining. In contrast, MLCK specific inhibitor reduced cellular proliferation. We concluded that MLCK, phosphorylated MLC and Ki67 were overexpressed in leiomyosarcoma. MLCK dependent MLC phosphorylation might be responsible for the high proliferative state in leiomyosarcoma. MLCK and phosphorylated MLC are potential prognostic indicators of leiomyosarcoma.

Diffusion-weighted magnetic resonance imaging for the initial characterization of non-fatty soft tissue tumors: correlation between T2 signal intensity and ADC values

To evaluate the performance of quantitative diffusion-weighted imaging (DWI) correlated with T2 signal in differentiating non-fatty benign from malignant tumors. A total of 76 patients with a histologically confirmed non-fatty soft tissue tumors (46 benign and 30 malignant) were prospectively included in this ethics committee approved study. All patients signed an informed consent and underwent MRI with DWI with two b values (0 and 600). ADC values from the solid components of these tumors were obtained and were correlated with the lesion's signal intensity on T2-weighted fat-saturated sequences. ADC values were obtained from adjacent normal muscle to allow calculation of tumor/muscle ADC ratios. There were 58 hyperintense and 18 iso or hypointense lesions. All hypointense lesions were benign. The mean ADC values for benign and malignant tumors were 1.47 ± 0.54 × 10(-3) and 1.17 ± 0.38 × 10(-3) mm(2)/s respectively (p < 0.005). The mean ADC ratio in benign iso or hypointense tumors was significantly lower than that of hyperintense ones (0.76 ± 0.21 versus 1.58 ± 0.82 - p < 0.0001). An ADC ratio lower than 0.915 was highly specific for malignancy (96.4%), whereas an ADC ratio higher than 1.32 was highly sensitive for benign lesions (90%). ADC analysis can be useful in the initial characterization of T2 hyperintense non-fatty soft tissue masses, although this technique alone is not likely to change patient management.

Two- and Three-Dimensional Ultrasound Imaging to Facilitate Detection and Targeting of Taut Bands in Myofascial Pain Syndrome

Ultrasound imaging has gained acceptance in pain management interventions. Features of myofascial pain syndrome have been explored using ultrasound imaging and elastography. There is a paucity of reports showing the benefit clinically. This report provides three-dimensional features of taut bands and highlights the advantages of using two-dimensional ultrasound imaging to improve targeting of taut bands in deeper locations. Fifty-eight-year-old man with pain and decreased range of motion of the right shoulder was referred for further management of pain above the scapula after having failed conservative management for myofascial pain syndrome. Three-dimensional ultrasound images provided evidence of aberrancy in the architecture of the muscle fascicles around the taut bands compared to the adjacent normal muscle tissue during serial sectioning of the accrued image. On two-dimensional ultrasound imaging over the palpated taut band, areas of hyperechogenicity were visualized in the trapezius and supraspinatus muscles. Subsequently, the patient received ultrasound-guided real-time lidocaine injections to the trigger points with successful resolution of symptoms. This is a successful demonstration of utility of ultrasound imaging of taut bands in the management of myofascial pain syndrome. Utility of this imaging modality in myofascial pain syndrome requires further clinical validation.

In Vivo Imaging of Tumor-Propagating Cells, Regional Tumor Heterogeneity, and Dynamic Cell Movements in Embryonal Rhabdomyosarcoma

Embryonal rhabdomyosarcoma (ERMS) is an aggressive pediatric sarcoma of muscle. Here, we show that ERMS-propagating potential is confined to myf5+ cells and can be visualized in live, fluorescent transgenic zebrafish. During early tumor growth, myf5+ ERMS cells reside adjacent normal muscle fibers. By late-stage ERMS, myf5+ cells are reorganized into distinct regions separated from differentiated tumor cells. Time-lapse imaging of late-stage ERMS revealed that myf5+ cells populate newly formed tumor only after seeding by highly migratory myogenin+ ERMS cells. Moreover, myogenin+ ERMS cells can enter the vasculature, whereas myf5+ ERMS-propagating cells do not. Our data suggest that non-tumor-propagating cells likely have important supportive roles in cancer progression and facilitate metastasis.

耳下部に発生した筋肉内脂肪腫例

The patient was a 64-year-old man with an infra-auricular mass. Since the tumor was strongly adherent to the angle and the posterior aspect of the mandible, part of the medial pterygoid muscle, masseter muscle, and parotid gland, it was bluntly dissected and resected en bloc. The resected tumor was measured 65×50×13 mm, and weighed 31 g. The tumor was histopathologically diagnosed as an intramuscular lipoma, presumably arising from the sternocleidomastoid or masseter muscle. The reported recurrence rate of non-infiltrating lipoma is less than 5%, whereas that of infiltrating lipoma ranges from 3 to 62.5%. Since intramuscular lipoma is characterized by an infiltrating growth pattern, it cannot always be completely resected. To reduce its recurrence, it is necessary to perform a wide en-bloc resection of the adjacent normal muscle, while considering the degree of residual muscle dysfunction, including muscle weakness.

The effect of the readthrough acetylcholinesterase variant (AChE-R) on uterine muscle and leiomyomas

Acetylcholine signaling and acetylcholinesterase (AChE) function(s) are pivotal elements in muscle development. The effects of the stimulus-dependent readthrough AChE variant, AChE-R, on leiomyomas and normal myometrium proliferation were assessed in vivo and in vitro. Histological preparations and cell cultures therefrom were obtained during hysterectomies or myomectomies and included both the leiomyoma sample and the adjacent normal uterine muscle as control. In situ hybridization procedures were performed using AChE cRNA probes complementary to the human AChE-R transcript. Antibodies against the AChE-R variant served for immunohistochemical staining. To determine the biological function of AChE-R on the uterine muscle cell cultures, we used a synthetic peptide representing the potentially cleavable morphogenically active C-terminus of AChE-R (ARP). Cell proliferation was assessed using the incorporation of 5'-bromo-2-deoxyuridine (BrDU). Leiomyomas expressed an excess of AChE-R mRNA and the AChE-R protein compared with the normal myometrium. Cell cultures originating from leiomyomas proliferated significantly faster than cultures from the adjacent myometrium (P = 0.027 at BrDU incorporation). Addition of ARP (2-200 nM) caused a dose-dependent decrease in the proliferation of cell cultures from both leiomyomas and the myometrium. The effect on the myometrium reached statistical significance (at 20 and 200 nM, P = 0.02), whereas the variability of the rapidly proliferating primary cultures was high and precluded statistical significance in the leiomyoma cultures. AChE-R is involved in the proliferation of the myometrium. The inhibitory effect of ARP on the myometrium may suggest a future therapeutic role of ARP.

Quantitative Time-Resolved Fluorescence Spectrum of the Cortical Sarcoma and the Adjacent Normal Tissue

The difference in time-resolved fluorescence spectrum between the cortical sarcoma and the adjacent normal tissue was studied in both experimental and theoretical ways. The Clinical data were obtained in vivo using a time-resolved fluorescence spectrometer employing a single fiber-optic probe for excitation and detection. Tissue was modeled as s-180 sarcoma tumor surrounded with normal muscle and was mediated by the Palladium-porphyrin photosensitizer (Pd-TCPP). The emitted fluorescence was considered as arising from the tumor tissue or the normal muscle, due to the presence of the photosensitizer. A computational code which could simulating time-resolved fluorescence emission was presented and applied to comparing fluorescence decay of photosensitizer in different stages of tumor growth. In this code the different stages of the tumor was modeled through changing the time tau, the delay of the fluorescence photon emission and z (max), the thickness of the tumor. It was found in the in vivo experiment that the fluorescence from tumor tissue decayed more quickly than from the adjacent normal muscle. For the ten rats in the first experiment day, the mean decay constant of tumor T (s) and normal tissue T (n) were 554 and 526 mus, respectively. And T (s) increased with the tumor growth, from 554 mus in the first day to 634 mus in the eighth day while T (s) kept steady. It was believed that the more adequate oxygen supplied by the normal tissue can more effectively quench the fluorescence and in the normal tissue the photosensitizer lifetime is smaller. As a result the simulated time-resolved fluorescence spectrum of normal tissue showed more quickly decay. And the thickness of the tumor can also delay the fluorescence decay. Both the experimental and simulated results indicated that the germination of the tumor would increase the decay constant of the time-resolved fluorescence spectrum. So decay constant of the tumor tissue spectrum should be larger than that of adjacent normal tissue for the reason of hypoxia and overgrowth. This fact could be of use in the tumor diagnoses.

Resistance of Tumor Interstitial Pressure to the Penetration of Intraperitoneally Delivered Antibodies into Metastatic Ovarian Tumors

Despite evidence that regional chemotherapy improves the treatment of metastatic peritoneal ovarian carcinoma, monoclonal antibodies have not shown significant success in i.p. delivery. The present study was designed to address the hypothesis that convective penetration of macromolecular antineoplastic agents depends on a positive pressure difference between the i.p. therapeutic solution and the tumor. Nude rats with human ovarian xenografts implanted in the abdominal wall were used in experiments to facilitate in vivo measurement of tumor pressure and the treatment of the tumor with i.p. solutions at high pressures. Penetration of (125)I-labeled trastuzumab was measured with quantitative autoradiography. Tumor pressure profiles showed peak pressures of 32 mm Hg with mean pressures (+/- SD, mm Hg) in 12 SKOV3 tumors of 9.7 +/- 8.3 and in 15 OVCAR3 tumors of 12.5 +/- 7.0. I.p. therapeutic dwells at 6 to 8 mm Hg (maximum feasible pressure) showed significantly less penetration of trastuzumab than in adjacent normal muscle. To establish a driving force for convection into the tumor, various maneuvers were attempted to reduce tumor pressure, including treatment with taxanes or prostaglandin E(1), elimination of tumor circulation, and removal of the tumor capsule. Tumor decapsulation decreased the pressure to zero but did not enhance the penetration of antibody. Binding to specific trastuzumab receptors on each tumor was shown to be not a significant barrier to antibody penetration. The results only partially support our hypothesis and imply that the microenvironment of the tumor is in itself a major barrier to delivery of charged macromolecules.

Distribution and photosensitizing efficiency of porphyrins induced by application of exogenous 5-aminolevulinic acid in mice bearing mammary carcinoma.

By means of a chemical extraction procedure and confocal laser scanning microscopy, we investigated the kinetic patterns of uptake and biolocalization of 5-aminolevulinic acid (ALA)-induced porphyrins in s.c. transplanted tumors, adjacent normal skin and muscle, and liver of mice bearing mammary carcinoma, after i.p. injection of 250 mg/kg ALA or topical application of ALA (20% in an oil-in-water emulsion). Furthermore, we evaluated the tumor responses after either i.p. injection or topical application of 5-ALA followed by laser irradiation (632 nm, 150 mW/cm2, 25 min) by measuring the treated tumor regression/regrowth time and by light and electron microscopy. Strong fluorescence of ALA-induced porphyrins was detected in the tumor, skin and liver tissues, while little fluorescence was seen in the adjacent muscle tissue. Moreover, the highest amounts of ALA-induced porphyrins in the tumor and skin tissues were found 1 hr after i.p. injection, whereas the amounts of the porphyrins in both tissues increased with increasing time after topical application of ALA. The fluorescence of the porphyrins was localized in several components of the skin tissue (epidermis, hair follicles and their associated sebaceous glands). Furthermore, the fluorescence was diffusely distributed in the s.c. transplanted tumor tissue. Little could be observed under a confocal laser scan microscope (CLSM) in the muscle tissue. The uptake and biolocalization data correlate well with the results of PCT efficiency of the same tumor model with ALA-induced porphyrins. Light and electron microscopy showed that the mitochondria of the tumor cells and of the endothelial cells and the basal lamina of vascular walls beneath the endothelium in the tumor tissue were initially extensively destroyed after PCT with ALA-induced porphyrins. Thereafter, diffuse degeneration followed by local and/or diffuse severe necrosis of the tumor cells was found. This may be due mainly to the initial damage to mitochondria in the cancerous and endothelial cells and also to the destruction of the vascular wall in the tumor tissue.

MR Imaging of Accessory Soleus Muscle

The accessory soleus muscle is an unusual anatomical variant that may present as a mass in the distal calf or medial ankle region. On both magnetic resonance (MR) and ultrasound, this variant has appearances similar to adjacent normal muscle. The diagnosis can be strongly suggested by typical location and by both echo texture and MR signal pattern of striated muscle.

Differentiation between acute and healed myocardial infarction by signal averaging and color encoding two-dimensional echocardiography

To evaluate the ability of a system developed in our laboratory to differentiate between acute and healed myocardial infarction (MI), gated 2-dimensional echocardiography was performed in 10 patients with recent MI (within 48 hours) and 10 patients with healed MI (later than 4 weeks). The 2-dimensional echocardiographic images were digitized using a Datacube VG-120 videoframe digitizer and each digitized videoframe (320 × 240 matrix) was transmitted using a high-speed serial data link to a second computer and stored on floppy disc. Five gated video frames of each patient were time-averaged to give a smoothed digitized image. This image was displayed on high-resolution color monitor connected to a color graphic subsystem. Sixty-four colors indicated pixel intensity. The exact pixel value at any given location was determined using a high-resolution light pen. Color or pixel values were not significantly different between the area of acute MI (pixel intensity 23 ± 3, mean ± standard deviation) identified by a regional wall motion abnormality, and the adjacent normal muscle (23 ± 4). In each patient with healed MI, an increase in color intensity and pixel value (43 ± 6) was seen in the area of MI (i.e., area of regional wall motion abnormality) compared with adjacent normal muscle (23 ± 2) (p < 0.001). These preliminary data in selected patients indicate that this technique enables differentiation between acute and healed MI. It could be of value in management of patients with suspected MI.

Changes in NMR relaxation times of adjacent muscle after implantation of malignant and normal tissue.

In separate experiments, normal foreign tissue and malignant tumour were implanted s.c. into the rat thigh. NMR T1 values of the adjacent normal muscle, resulting from local inflammatory reactions or from malignant invasion, were measured. Elevations in T1 of the underlying muscle occurred within 24 h in both experiments, and it is believed these were caused by rapid inflammatory and immunological reactions to the implants. However the T1 values of muscle samples adjacent to the non-malignant implants decreased during the 11 days after implantation, dropping to values within the normal range. In the second experiment there was progressive malignant invasion into the normal adjacent tissue and the elevated T1 values were maintained throughout the 12-day period. The effects of the implantation on tissue water content are discussed in relation to NMR T1 relaxation times, and the relevance to whole-body NMR imaging of elevated T1 values due to nonmalignant pathological states is considered.

Azure B Bromide Staining of Regenerating Muscle

Paraffin sections of regenerating muscle fibers color intensely blue or purple with the metachromatic stain azure B bromide. These darkly stained fibers show excellent cellular detail in cytoplasm as well as nuclei. They contrast conspicuously with the pale blue of adjacent normal muscle. Differential staining of nucleic acids is the principle on which this technic is based. With stain dissolved in water at a pH of 4.0, the ribonucleic acid (RNA) stains purple and deoxyribonucleic acid (DNA) stains blue-green. Early work with azure B bromide was done by Flax and Himes. They and Lash and associates demonstrated that treatment of sections with ribonuclease (RNAse) before staining eliminated the purple color. This stain has been used very satisfactorily in our laboratory for a study of the basophilia of regenerating muscle, the pathology of human muscular dystrophy, and the inflammatory disorders of muscle. We have obtained good results from it also with regenerating diaphragm and rectus abdominis muscle of rats which had been inoculated intraperitoneally with the myotoxic substance plasmocid.* 8 ' Procedures for using azure B bromide are not, to our knowledge, generally included in current histologic technic books, nor do they seem to be well known. It is the purpose of the present paper to call attention to some of the literature on this subject, to describe briefly the technic of using azure B bromide, and to emphasize that it is probably not strictly accurate to refer to this stain simply as azure B, as has been done in some previous publications. •

Rupture of the heart in myocardial infarction: Clinical and pathologic observations ∗

Rupture of the heart in eight cases of myocardial infarction and a review of the literature are presented. The condition appears to occur more often than the literature would indicate. It affects an area of the heart where fresh myocardial damage is present, but never in areas of organized infarction. In the majority of patients it occurs in the free wall of the left ventricle, mainly in the anterolateral region close to the apex, and may involve portions of the lower interventricular septum. In occasional cases it may affect the interventricular septum alone and rarely it may be confined to the papillary muscle. One or more of the underlying predisposing causes are pre-existing and coexisting hypertension with its strain on the heart and hypertrophy of the myocardial fiber; the female sex in whom hypertension is more frequent; the older age groups where the normal histologic structure of the myocardium is altered; an early age of the infarct; the effect of leukocytic infiltration with its local enzymatic destructive effect on the myocardium; and the location of the coronary occlusion usually in the anterior descending branch of the left coronary artery. The most important direct cause appears to be an aneurysmal-like expansion of the devitalized myocardium in the area of infarction during systole which produces a suction effect on the blood in that area. This probably causes over-distention and rupture of the arterioluminal and arteriosinusoidal vessels with dissection of blood through the myocardium. Pressure exerted by contraction of the adjacent normal heart muscle upon the devitalized area also causes tearing of the diseased myocardial tissue. The diagnosis of rupture of the free wall of the heart during life is hard to make but in perforation of the interventricular septum the diagnosis is relatively easy to establish. Treatment of the condition when affecting the free wall should, therefore, be prophylactic. The condition must be borne in mind in any case of myocardial infarction especially when it occurs under the aforementioned circumstances, and careful management of the acute phase of infarction is to be instituted. In perforation of the interventricular septum treatment should be symptomatic and directed toward heart failure.