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J Thorac Cardiovasc Surg 1999;118:760-764
© 1999 Mosby, Inc.
CLINICAL-PATHOLOGIC CONFERENCE |
This case, with added links and enhanced graphics, is available for further study on the Web at: http://www.ctsnet.org/doc/3196.
Participants
From the Washington University School of Medicine
Barnes-Jewish Hospital
St Louis, Missouri
THORACIC SURGERY
Dr Joel Cooper
Dr G. Alexander Patterson
Dr R. J. Schreiner
RADIOLOGY
Dr Claire Anderson—Chest Radiology
SURGICAL PATHOLOGY
Dr Jon Ritter
Dr Maureen O’Sullivan
Case presentation
Dr Schreiner:
A 34-year-old woman presented to her primary care physician’s office with dysphagia. She first experienced the dysphagia 10 years earlier during her pregnancy, and it failed to resolve after delivery. The dysphagia progressively worsened to the point of causing her to vomit several times a week, 4 to 8 hours after eating. She self-medicated herself with antacid (Mylanta) and various home remedies without adequate relief. Her primary care physician ordered an upper gastrointestinal tract series. Unfortunately, these films were not available. There was considerable variability in the caliber of the esophagus with regions that were quite distended. The maximum diameter in some areas extended up to 4 cm. Also noted was an irregularity in the lining of the esophagus. This irregularity did not appear to be associated with an intrinsic mass, but rather the possibility of some significant abnormality in the musculature associated with the esophagus. There did appear to be some variable contractility of the lower esophagus. A hiatal hernia was also noted. The remainder of the upper gastrointestinal tract was normal. Dr Anderson, have you any comments on that report?
Dr Anderson:
That is a fascinating report in view of the other findings. The chest radiographs (Fig 1, A and B ) demonstrate a large middle mediastinal mass in the region of the esophagus. In fact, 2 separate masses in the middle mediastinum are suggested, 1 centered at the carina and the other centered at the diaphragm. On the lateral view, the proximal mass is more obvious. This proximal mass is approximately 6 cm in width and 10 cm in cephalocaudal dimension. The lower mass has similar dimensions. On the computed tomographic scan (Fig 2, A to D ), the soft tissue masses, measuring approximately 7 x 4 cm in greatest axial dimensions, are intimately associated with the esophagus, although the lumen of the esophagus is quite smooth. Barium in the esophageal lumen clearly defines esophageal distention proximal to the mass. The marked distention suggests at least functional obstruction. The lobulated appearance (Fig 2
, A ) suggests that tumor would be obvious at esophagoscopy. The second mass extends to the gastroesophageal junction but does not seem to involve the fundus per se. No adenopathy, either in the gastrohepatic region or in the mediastinum, is defined on the computed tomographic images.
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Dr Anderson:
This is a rare lesion. Leiomyoma is the most common benign tumor of the esophagus, but it is rare for leiomyomas to be multiple. Leiomyomas of this size in other regions of the gut would suggest a sarcoma.
Dr Cooper:
Diffuse leiomyomas can be associated with Alport syndrome. This syndrome is due to a genetic defect. Patients have renal, ocular, and auditory abnormalities, as well as marked hypertrophy of the esophageal smooth muscle. These esophageal lesions can sometimes reach enormous proportions—with a mass the size of a football.
Dr Schreiner:
As part of her work-up before coming to see us, the patient had a nuclear medicine scan to eliminate lymphangioma from the differential diagnosis. No isotope activity was evident within the lesion, thus eliminating that possibility. At that point, the patient was referred to our service. At the time of our esophagoscopy we confirmed the previous findings. In the absence of a specific diagnosis, we decided to proceed with a right posterolateral thoracotomy to establish a diagnosis and, ideally, salvage the esophagus. The complex bicomponent mass was within the esophageal wall. In fact, the outer longitudinal layer was intact. The outer muscle layer was opened throughout the length of the thoracic esophagus. This exposed the discrete mass within the circular muscle layer. It extended several centimeters proximal to the azygos vein to the hiatus. We attempted to peel the mass away from the underlying mucosa. It was quite easy to develop a satisfactory plane over the entire extent of the lesion. However, this left a long length of uncovered mucosa.
Dr Cooper:
Usually, with these esophageal leiomyomas the lesion can easily be dissected off the mucosa. In this patient that would have resulted in a tube of esophageal mucosa with no surrounding muscular wall, certainly an inferior functional result.
Dr Schreiner:
Over what length do you think an esophageal leiomyoma can be successfully enucleated without considering an esophageal resection?
Dr Cooper:
For a partially circumferential tumor extending over a few centimeters, the muscle can be split, the tumor peeled out, and the muscle put back together. I am sure this tumor was not like that. I suspect this looked like a mass of hypertrophic muscle and not a smooth, discrete-margined tumor embedded in the wall of the esophagus.
Dr Patterson:
It seems to me that a lesion of considerable length could be shelled out and the muscle reapproximated with expectation of a satisfactory result. However, in this patient we did not have muscle available to close over the exposed mucosa.
Dr Schreiner:
We will look at the gross photographs subsequently. Intraoperatively, esophageal preservation was deemed to be impossible. After resection of the thoracic esophagus, the patient was turned in the supine position, and a laparotomy and incision in the left side of the neck were performed. The stomach was mobilized and transposed through the posterior part of the mediastinum to the neck, where a standard cervical esophagus–to–stomach anastomosis was performed with the Endo GIA stapler (United States Surgical Corporation, Norwalk, Conn). The patient made a smooth postoperative recovery. At present, 8 months after resection, she is doing well. Perhaps we could review the pathologic features.
Dr O’Sullivan:
The freshly resected specimen is shown in Fig 3, A. The muscular layer has been surgically split longitudinally over the proximal half of the specimen, the mucosal tube remaining intact revealing a lobulated intramural mass. A further nodular mass is present deep to the intact muscle of the lower esophagus. In Fig 3, B, the entire specimen has been opened longitudinally. The mucosal lining of the upper portion is smooth. However, distally the nodular irregularity reflects submucosal tumor extension. Focal mucosal ulceration is evident also (arrow) in this area.
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Frozen sections of the pulmonary ligament lymph node showed no evidence of tumor. Frozen section of a biopsy specimen from the mass was interpreted as "benign spindle cell neoplasm, favor leiomyoma."
Fig 5 shows splaying apart of the skeletal muscle fibers by infiltrating smooth muscle tumor cells at the proximal resection margin. Given the extensive esophageal involvement and the diffusely infiltrative growth pattern of this tumor, a diagnosis of diffuse leiomyomatosis was rendered.
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Dr Ritter:
Malignant smooth muscle tumors of the esophagus are almost reportable cases. No matter what size they are, they are still almost always benign. In my 11 years at this institution, I have not heard of one being resected.
Dr O’Sullivan:
Diffuse leiomyomatosis involving the esophagus and the female genital tract was first described radiologically in 1973. Classically, the syndrome involves the esophagus, the tracheobronchial tree, and the female genital tract. Gastrointestinal symptoms can include dysphagia, odynophagia and retrosternal pain, regurgitation, and bleeding. Resection is the recommended treatment. There is a risk of recurrence at the anastomosis site. Tracheobronchial involvement usually presents as paroxysmal dyspnea and mimics asthma. Interestingly, in several case reports, including this one, there was an eosinophilic infiltrate, and the suggestion has been made that perhaps there is an allergic component to the disease. The genital manifestations are usually confined to women, typically involving the perineum. Lesions can extend posteriorly to involve the rectum and anteriorly to the vesical collar. Urethral leiomyomas have also been reported. In addition, uterine leiomyomas may occur in these patients. Insight into the genetic basis of this disease came from the observation of several families with a combination of Alport syndrome and leiomyomatosis. Alport syndrome comprises hereditary hematuria and nephropathy, sensori-neural deafness, and ocular lesions including congenital cataracts. The gene responsible for Alport syndrome is the type IV collagen alpha-5 gene, which is located on the long arm of the X chromosome. Families in which features of both Alport syndrome and leiomyomatosis were observed actually had lesions of the type IV collagen alpha-5 gene, the lesion extending beyond the 5' end of this gene. The gene for a diffuse leiomyomatosis was thought to reside in this portion of the X chromosome, and subsequently the type IV collagen alpha-6 gene has been localized to this region. The genes are oriented in the head-to-head position, so the 5' ends are adjacent to each other. No type IV collagen alpha-6 mutations have been found in Alport syndrome. Our recommendation would be to examine for features of Alport syndrome and test the rest of this patient’s family if she does not yet have any family history.
Dr Cooper:
We should check her genes.
Dr O’Sullivan:
We have saved fresh-frozen tissue for genetic analysis. Additional blood specimens taken subsequent to resection are under review.
Dr Cooper:
Were there positive margins in this patient?
Dr O’Sullivan:
The tumor extended to within 0.1 cm of the proximal margin. The distal margin was free.
Dr Patterson:
At the time of resection we believed that our gross margins were quite clear. In fact, we did not obtain a frozen section from the proximal margin because I thought we were free of the obvious tumor mass. Perhaps the permanent-section close margin has more to do with specimen retraction in formalin. In any case, I am reluctant to subject this young woman to adjuvant radiotherapy for what is likely a benign low-grade lesion.
Received for publication July 15, 1999. Accepted for publication Aug 3, 1999.
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