Primitive Malignant Fibrous Histiocytoma of the Neck With Carotid Occlusion and Multiple Cerebral Ischemic Lesions
Background Emergence of a malignant tumor at the site of an operation is a rare event and most often arises in association with retained foreign material.
Case Description We describe a patient who 1 year after a left carotid endarterectomy for typical atheromatous lesions presented with several transient ischemic attacks with stepwise worsening of the deficit and rapid death. A few weeks before, a tumor of the neck had appeared at the site of the previous endarterectomy. At postmortem examination, we found a malignant histiocytofibroma occluding the left carotid artery, with several recent ischemic foci in the corresponding cerebral hemisphere without metastasis or tumor emboli.
Conclusions This observation is unusual owing to the histological type of the neoplasm and to the circumstance of emergence of the neoplasm.
Emergence of a malignant tumor at the site of an operation is a rare event and most often arises in association with foreign material.1 2 3 We report the case of a man who developed a malignant fibrous histiocytoma at the site of a previous carotid endarterectomy performed 1 year before.
A 73-year-old man was admitted to the hospital for a sudden right-sided weakness. One year before admission, he had presented with several episodes of right transient brachial monoparesis, which were found to be due to a severe left internal carotid stenosis. A thromboendarterectomy of the left proximal internal and distal common carotid arteries was performed. The lumen was 90% stenosed by an atherosclerotic plaque at macroscopic examination (no pathological examination was performed). After the operation the patient did well, and 8 months afterward there was no abnormality of the artery at Doppler sonography. Two months later the patient experienced brief episodes of right transient crural monoparesis and then the symptoms that led to hospitalization. On admission the patient presented with a paresis of the right lower limb, followed quickly by a partial recovery; however, 2 days later he had a new attack of severe right-sided hemiparesis. Doppler sonography showed a left internal carotid occlusion by an anechogenic material and an atheromatous plaque at the bifurcation. A cranial CT scan showed no focal hypodensity. During hospitalization the patient complained of a pain in the left side of the neck during swallowing. On physical examination no mass was found, and a diagnosis of postoperative fibrosis was made. Analgesics were prescribed, and the pain decreased. A few weeks later a left lateral neck mass was discovered after a worsening of the local pain. On physical examination the patient presented with a marked right hemiparesis. Doppler sonography still showed an occlusion of the left primitive carotid and internal carotid arteries. A cranial CT scan showed a small left cortical infarct. Ultrasonography of the neck mass showed a heterogeneous, fixed, hypoechogenic and hyperechogenic mass measuring 30 mm in diameter located anterior to the sternocleidomastoideus, suggesting a lymph node enlargement. Before the decision to operate was made the physical state of the patient worsened, and he died 1 week later. An autopsy restricted to the area of the neck mass and to the brain was performed.
At postmortem examination a firm, solitary, multilobated, pseudoencapsulated tumor 10×6×4 cm was found in the area of the left carotid bifurcation. On cut sections the mass was surrounding the carotid artery, and surgical threads (from the previous carotid endarterectomy) were found within the tumor. Microscopic examination revealed a relatively well-circumscribed tumor consisting of clump spindle cells arranged in a storiform pattern and in giant multinucleated cells. The mitotic activity was high, with 17 mitoses per 10 high-power fields. The stroma consisted of collagen fibrils, occasionally with a marked collagenization or focal myxoid change. The vasculature consisted of small vessels with areas of hemangiopericytoid pattern. Large areas of necrosis were widespread in the tumor. This malignant proliferation was surrounding, infiltrating, and occluding the carotid artery. At immunochemistry, the tumor was negative for the epithelial markers (CYTO K−, EMA−) and for protein S 100 (a marker of melanoma and Schwann cell tumor), positive for vimentin (mesenchymal marker), and negative for desmin and HHF35 (muscular markers). The diagnosis of storiform pleomorphic type grade 3 malignant fibrous histiocytoma was made. Multiple foreign body granulomatous reactions were found in the proximity of the tumor around the surgical threads of the previous endarterectomy.
Macroscopic examination of the brain showed a few small nonocclusive atheromatous deposits in the vessels of the circle of Willis. The coronal sections revealed several whitish areas in the subcortical white matter of the left cerebral hemisphere. At the microscopic level, recent ischemic lesions were observed in the left temporal, frontal, and parietal cortex and in the left hemispheric white matter. No metastasis or emboli of the malignant fibrous histiocytoma were seen in the brain.
The diagnosis of left multiple ischemic brain foci secondary to left carotid occlusion by the malignant fibrous histiocytoma was established.
Malignant fibrous histiocytoma is a soft-tissue tumor of late adult life; the majority of cases occur in people older than 50 years.4 5 The common locations are the extremities, followed by the retroperitoneum. The neck is a very unusual site4 5 ; only one other case of malignant fibrous histiocytoma of the neck has been reported, to our knowledge.6
The development of a malignant tumor at the site of an operation is very unusual. Although it seems unlikely, the first possibility is that the tumor was present at the time of the endartectomy, in the absence of pathological examination to rule out this hypothesis. The second possibility, which we find more plausible, is the emergence of the malignant tumor on the scar of the endarterectomy. Indeed, a few cases of sarcoma arising at the site of a previous operation have been reported.1 2 3 In most of these cases, the sarcoma was associated with foreign material and arose after a very variable latency period.1 2 3 The foreign material may have different physicochemical characteristics and mainly is associated with prostheses for joint replacement and vascular grafts.1 2 3 In our case surgical threads were found within and in the vicinity of the malignant proliferation and therefore could have induced tumorigenesis. Studies in animals have shown that the physical presence and not the chemical components of the implant of foreign bodies may be responsible for tumorigenesis.7 The most critical factor in the induction of these sarcomas is the formation of a fibrous capsule around the foreign body.7 In our case the persistence of a foreign body granulomatous reaction and the presence of large extensive fibrosis areas in the tumor seem to be in agreement with this possibility. Since the number of carotid endarterectomies is increasing after the positive results of several prevention trials, the possibility of occasional induction of sarcomas at the site of the operation should be kept in mind.
We are grateful to Professor Boris Sandler for the translation of the Russian article6 and to Ray Cooke for linguistic help.
Reprint requests to M.-L. Martin-Negrier, MD, Service d’Anatomopathologie, CHR Pellegrin, F-33076 Bordeaux, Cedex, France.
- Received August 21, 1995.
- Revision received November 6, 1995.
- Accepted November 21, 1995.
- Copyright © 1996 by American Heart Association
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