Ann Thorac Surg 2001;72:625-627
© 2001 The Society of Thoracic Surgeons
Case report
Incidental malignancy in internal thoracic artery lymph nodes
Lin-Rui Guo, MDa,
Mary Lee Myers, FRCSCa,
Mary Ellen Kirk, FRCPCb
a Division of Cardiovascular Surgery, London Health Sciences Centre—Victoria Campus, London, Ontario, Canada
b Department of Pathology, London Health Sciences Centre, Victoria Campus, London, Ontario, Canada
Accepted for publication July 10, 2000.
Address reprint requests to Dr Myers, Division of Cardiovascular Surgery, London Health Sciences Centre—Victoria Campus, 370 South St, Room C101, London, ON N6B 1B8, Canada
e-mail: ml.myers{at}lhsc.on.ca
 |
Abstract
|
|---|
The incidental finding of malignant internal thoracic lymph nodes while mobilizing the internal thoracic artery (ITA) for coronary bypass grafting has not to our knowledge been previously reported. The cases of 3 male patients who underwent surgery between January 1990 and January 1993 and in whom malignant lymph nodes were found in the ITA pedicle are reviewed. One individual was found to have metastatic carcinoma of the breast, whereas the other 2 were discovered to have previously undiagnosed lymphomas. After undergoing further relevant investigation and treatment, all 3 patients remain free of recurrent disease 6.8 to 9.8 years after their original cardiac surgery. Primary or metastatic malignancy may be encountered in the course of ITA mobilization for grafting. Abnormally enlarged internal thoracic lymph nodes should be sent for pathologic examination.
|
Introduction
|
|---|
The excellent long-term patency of internal thoracic artery (ITA) grafts is widely documented [1, 2]. As a result, ITA grafting has become a standard component of myocardial revascularization procedures. Data from The Society of Thoracic Surgeons’ national database has documented a progressive increase in the use of at least one ITA in coronary bypass operations: the 1996 level was approximately 77% as compared to 47% in 1990 [3]. In many practices including our own, at least one ITA is used in essentially all coronary bypass procedures. Although there are some proponents of a skeletonization technique, most surgeons mobilize the artery in conjunction with a pedicle of tissue that includes accompanying veins, lymphatic channels, and lymph nodes. Herein we report 3 cases of malignant internal thoracic lymph nodes discovered incidentally at the time of ITA pedicle mobilization for coronary grafting.
|
Case reports
|
|---|
Patient 1
A 68-year-old man was admitted to the hospital for elective coronary bypass surgery in January 1990. His medical history included a left modified radial mastectomy for treatment of a 2.5-cm infiltrating duct carcinoma 5 years previously. The axillary lymph nodes were free of disease at the time of mastectomy and the patient had remained clinically free of recurrent disease. With mobilization of the left ITA the midportion of the pedicle was found to be encased in firmly adherent tissue and multiple enlarged lymph nodes and a quick section biopsy was reported as being highly suggestive of malignancy. In view of this the entire pedicle was widely dissected and sent for pathologic examination. A double coronary bypass was carried out using long saphenous vein to graft both the left anterior descending and intermediate branches. The pathology report indicated nodal and extranodal adenocarcinoma consistent with breast cancer and histochemically negative for estrogen receptors. A metastatic survey was negative and the patient was initially followed without adjuvant treatment. In February 1996 he was noted to have a poorly defined, firm, mobile 3 to 4-cm axillary mass. During induction of general anesthesia for axillary dissection he developed acute pulmonary edema. Subsequent investigation demonstrated significant aortic stenosis and occluded saphenous vein grafts and the patient underwent urgent aortic valve replacement and single coronary artery bypass. He was started on tamoxifen 20 mg daily. The axillary mass regressed and there has subsequently been no evidence of recurrent disease.
Patient 2
A 67-year-old man was admitted to the hospital in June 1990 for transurethral prostatic resection but developed severe angina at rest. Coronary angiography demonstrated total proximal occlusions of both the circumflex and right coronary arteries, a 50% stenosis of the proximal left anterior descending artery, and normal left ventricular contractility. A triple coronary artery bypass procedure was carried out on an urgent basis using the left and right internal thoracic arteries to graft the left anterior descending and circumflex marginal branches with a saphenous vein graft to the distal right coronary artery. A firm, oval 1.5-cm lymph node was noted in the proximal portion of the left ITA pedicle and sent for pathologic review. Microscopic examination demonstrated completely effaced architecture with diffuse infiltration of relatively mature lymphocytes as well as extension through the capsule of the node in several areas. The pathologic diagnosis was of a well differentiated, diffuse lymphocytic lymphoma of the small lymphocytic type. A computed tomographic scan of the abdomen and bone marrow biopsy were negative and the decision was initially made to follow the patient without treatment. Approximately 1 year later he developed a mild cough and a computed tomographic scan of the chest demonstrated enlarged aortic and pulmonary lymph nodes. He was also noted to have axillary lymphadenopathy. A six-cycle course of chlorambucil chemotherapy was initiated with resolution of his symptoms and lymphadenopathy. He remains in remission 9.5 years after the initial diagnosis and is free of any symptoms of ischemic heart disease.
Patient 3
A 55-year-old man with severe multivessel coronary disease and normal left ventricular contractility was admitted to the hospital for elective coronary bypass surgery in January 1993. At surgery the thymic remnant was noted to be somewhat enlarged and firm in consistency and was excised and sent for quick section pathology examination. The intraoperative report cited cystic follicular changes with no evidence of malignancy. The left ITA was used to graft the left anterior descending artery with saphenous vein grafts to the diagonal, the circumflex marginal artery, and the posterior interventricular branch of the right coronary artery. Several mildly enlarged lymph nodes in the ITA pedicle as well as two additional lymph nodes in proximity to the innominate vein were also excised and sent for pathologic examination. The final diagnosis was of a poorly differentiated, diffuse malignant lymphocytic lymphoma of intermediate grade. Cytometry was consistent with a B-cell lymphoma. Subsequent staging revealed bone marrow involvement. Chemotherapy consisting of cyclophosphamide, adriamycin, vincristine, and prednisone was initiated. After six cycles the bone marrow was normal and a complete remission was achieved. The patient has continued to do well in follow-up 7 years later and also remains asymptomatic with respect to his coronary artery disease.
|
Comment
|
|---|
Malignant lymph node involvement can occur with primary malignancies (most commonly the lymphomas) or with metastatic spread from other sites. Although the term lymphoma encompasses a broad range of lymphoproliferative disorders, these are generally divided into two major categories: Hodgkin’s disease and lymphocytic lymphoma. Lymphocytic lymphoma, the diagnosis in 2 of the cases reviewed here, is the seventh most common cause of malignancy in the United States and the incidence appears to be rising [4]. Although there is a relatively wide range in age at presentation, the mean age at diagnosis in North Americans is in the fifth decade. Carcinomas disseminate through lymphatic spread with the pattern of lymph node involvement following the usual routes of lymphatic drainage. Metastatic involvement of internal thoracic lymph nodes occurs most commonly due to tumors of the breast.
The intraoperative discovery of malignant internal thoracic lymph nodes was not associated with concurrent clinical symptoms of malignant disease in the cases reported here. It is unlikely that the intraoperative diagnosis of metastatic disease will ultimately affect the course of the disease process in patient 1. The decision to commence treatment with tamoxifen was based on a subsequent finding of axillary adenopathy and presumably would have occurred regardless of the intraoperative diagnosis. In the case of patient 2, however, awareness of the diagnosis at an early stage may have influenced the course of the disease. Although well-differentiated lymphocytic lymphomas of the small lymphocytic type are associated with a good prognosis, it is not unreasonable to assume that appropriate investigation and treatment were instituted more expeditiously because of the preexisting awareness of the diagnosis. In the case of patient 3 it is likely that the intraoperative discovery of malignancy favorably altered the natural course of the disease. Although the 5-year survival for a poorly differentiated lymphocytic lymphoma with intrathoracic lymph node and bone marrow involvement is generally estimated to be in the range of only 40% to 50%, this individual continues to be disease-free 7 years postoperatively.
In summary, the internal thoracic lymph nodes may be the site of malignancy, either primary or secondary, and pathologic nodes may be encountered in the course of ITA mobilization for grafting. It is conceivable that obtaining payment for pathologic studies unrelated to the primary diagnosis may be problematic in some health care systems. Based on our experience, however, we would conclude that abnormally enlarged internal thoracic lymph nodes encountered during cardiac surgery should be sent for pathologic examination. Furthermore, the excellent clinical results obtained to date in the 2 lymphoma patients cited suggests that the presence of an incidental lymphoma should not necessarily preclude use of the ITA for grafting.
|
References
|
|---|
-
Lytle B.W., Loop F.D., Cosgrove D.M., Ratliff N.B., Easley K., Taylor P.C. Long-term (5 to 12 years) serial studies of internal mammary artery and saphenous vein coronary bypass grafts. J Thorac Cardiovasc Surg 1985;89:248-258.[Abstract]
-
Fiore A.C., Naunheim K.S., Dean P., et al. Results of internal thoracic artery grafting over 15 years: single versus double grafts. Ann Thorac Surg 1990;49:202-209.[Abstract]
-
Grover F.L. The Society of Thoracic Surgeons National Database: current status and future directions. Ann Thorac Surg 1999;68:367-373.[Abstract/Free Full Text]
-
Urba WJ, Longo DL. Lymphocytic lymphomas: epidemiology, etiology, pathology, and staging. In: Moossa AR, Schimpff SC, Robson MC, eds. Comprehensive textbook of oncology, vol 2. Baltimore: Williams and Wilkins, 1991, 1268–77.
This article has been cited by other articles:
|
|
|
|
 
V. Vijay and J. P. Gold
Late Complications of Cardiac Surgery
Card. Surg. Adult,
January 1, 2003;
2(2003):
521 - 537.
[Full Text]
|
|
|
|
|
|
|
A. Sachithanandan, B. Badmanaban, A. Graham, and H. O'Kane
Malignant internal mammary lymph nodes during mobilization of the internal mammary artery
Eur. J. Cardiothorac. Surg.,
November 1, 2002;
22(5):
847 - 848.
[Abstract]
[Full Text]
[PDF]
|
|
|
Top
Abstract
Introduction
