LEIOMYOSARCOMA O F THE S A P H E N O U S VEIN
E. GROSS Surgical Registrar, Whipps Cross Hospital, London, E.11
M. A. HORTON" House Surgeon, Whipps Cross Hospital, London, E.11
PLATESIX
AND
X
LEIOMYOSARCOMAS arising in the venous system are a rare occurence. This paper reports a primary growth arising in the saphenous vein with unusual metastases to the thyroid gland and subcutaneous tissue. CASEREPORT A 46-year-old white man was referred in January 1970 to the out-patient department complaining of a painless lump on the right thigh, present for 2 yr, which had recently begun to enlarge. There was n o history of trauma. His previous medical history was noncontributory. Physical examination revealed a fit, well-nourished adult male with a 5 x 5 cm firm nontender mass in the upper medial right thigh, approximately 15 cm below the inguinal ligament. There was attachment to deep fascia, but not to the overlying skin. The mass did not transilluminate or fluctuate and no enlarged lymph-nodes were palpable. Distally the limb was of normal size and no oedema or varicosities were present. There was no hepatomegaly. The anterior abdominal wall was normal and it was noted that there was no thyroid gland enlargement. Exploration of the right thigh revealed a tumour-like mass growing along the lumen of the saphenous vein and expanding the vessel at the site of the palpable swelling. The portion of the vein containing the tumour was excised and an uneventful recovery ensued. Examination of the specimen revealed an anaplastic spindle-celled tumour of the saphenous vein with the typical histological features of a leiomyosarcoma. The tumour was composed of whorled and interlacing bundles of plain muscle cells with large hyperchromatic nuclei. There were pleomorphic and giant celled areas with a moderate number of mitoses. Differentiation was variable, in parts being quite well differentiated (fig. 1). Almost 3 yr later (January 1973) the patient was re-admitted, having noticed the sudden appearance of a painless swelling in the left side of his neck in the region of the thyroid gland. He had no symptoms suggestive of toxicity or dysphagia and his voice was unchanged. His weight was steady. There was no past or family history of goitre. There was a 3 x 3 cm hard, solitary nodule in the left lobe of the thyroid gland with no retrosternal extension. There was no clinical evidence of toxicity. No enlarged lymph-nodes were palpable and the trachea was central. There was no evidence of local recurrence in the scar on the right thigh. Thyroid function tests confirmed euthyroid status. Chest X-ray showed no abnormalities and X-ray of the thoracic inlet revealed some displacement of the trachea to the right, but no compression or calcification. Received 28 June 1974; accepted 4 July 1974.
* Present address: Department of Pathology, St Bartholomew's Hospital, London, E.C.l I. PATH.-VOL.
116 (1975)
37
38
E. GROSS AND M. A . HORTON
A near total thyroidectomy was performed through a collar incision. There was a stony-hard nodule occupying most of the left lobe of the thyroid gland while the isthmus and the right lobe were small and not macroscopically involved with tumour. Post-operatively the vocal cords were moving normally, he was never hypocalcaemic and was discharged on a maintenance dose of L-thyroxine. Histological examination of the thyroid specimen revealed a much more pleomorphic tumour, with increased fibrosis modifying the histological features. Fairly well differentiated plain muscle cells mingled with spindle-celled and giant-celled areas. Mitoses were numerous and often bizarre. The thyroid follicles were encircled by growth and atrophied. This was considered to be consistent with a secondary deposit of leiomyosarcoma in the thyroid gland (fig. 2). The patient was then treated with Telecobalt irradiation and the 15 meV linear accelerator, receiving 6500 r to the anterior neck and cervical node regions. Regular follow-up revealed no evidence of local recurrence until October 1973 when it was noted that he had two small subcutaneous nodules in the left hypochondrium. An excision biopsy was performed and histology confirmed fairly well-differentiated, occasionally anaplastic, secondary leiomyosarcoma nearer in structure to the primary turnour (fig. 3). At his most recent follow-up visit the patient remains clinically well with no sign of recurrence at any of the three sites. His chest X-ray is clear, there is no hepatomegally and his E.S.R. is within normal limits.
DISCUSSION Reviews of the world literature on primary vascular leiomyosarcomas have all agreed on the rarity of the lesions-some 86 reports since the first valid case of leiomyosarcoma in the inferior vena cava was reported by Per1 in 1871 (cited by Kevorkian and Cento, 1973). Although the inferior vena cava seems to be particularly involved (33 reports), the next most common sites are the femoral and long saphenous veins. Kevorkian and Cento (1973) discovered reports of eight primary leiomyosarcomas in large systemic arteries. The majority of cases involving the saphenous vein have been reported since De Weese’s case in 1958, and this probably reflects an increased awareness of this uncommon tumour rather than an altered incidence. Most of the lesions have been found in the proximal part of the saphenous vein (eight out of 14 reports) in the groin or thigh, particularly in the more recently published cases. The features of previously recorded saphenous vein smooth muscle tumours are summarised in the table. Certain characteristics distinguish saphenous vein from other venous leiomyosarcomas. The sex ratio (M :F; 9 :5 ) shows a male predominance compared with the well-recognised but unexplained excess of female cases involving the inferior vena cava. Venous obstruction leading to varicose veins or leg oedema is less common the more distal the site of the tumour, in practice only occurring in lesions affecting the saphenofemoral junction. We did not detect evidence of excessive collateral venous circulation in our patient. There is little tendency to intraluminal growth, although this is noted in the inferior vena cava where the tumour may float free within the blood stream. Metastatic spread is uncommon from the smaller vessels, the majority being slow growing and localised, invading only surrounding tissues or adjacent skin. The distribution of secondaries, with thyroid and subcutaneous deposits, in this case is unusual in that the majority of metastasising leiomyosarcomas involve the lungs and liver predominantly and other sites infrequently. Malignant mesenchymal neoplasms of the thyroid gland are rare except for
39
LEIOMYOSARCOMA OF VEIN
lymphomas, the most common type being fibrosarcoma. Primary smooth muscle tumours arising in the thyroid gland are extremely rare, only single cases of leiomyoma (Hendrick 1957) and leiomyosarcoma (Adachi et d.,1969) having been described. Secondary deposits in the thyroid gland are common in epithelial malignancy (Silverberg and Vidone, 1966) but unusual in sarcomas on non-lymphoid origin, this case being the first report of a secondary leiomysarcomatous deposit in the thyroid gland. Spread from a remote primary site TABLE Primary smooth muscle tumours arising in the saphenous vein __
reported
Author
Sex
Age
Site
Spread
Histology
- -
1868 1906 1917 1919
Aufrecht Borchard Ecoffey Van Ree
M
1958 I960 1963 1963
M F
23 44 40 42
Ankle Ankle Leg Leg
De Weese et al.
M
54
Saphenofemoral jtn
F M M
76 59 56
Thigh Thigh Knee
0 0 0
1964 1965
Smout et al. Dijkstra Dorfman et al. Christiansen Allison
Leiomyoma ( ?) low-grade sarcoma Leiomyosarcoma Leiomyosarcoma Leiomyosarcoma
F F
64 3
0 0
Leiomyosarcoma Leiomyosarcoma
1966 1969
stout Szasz et al.
F M
50 68
Thigh Saphenofemoral jtn Branch Thigh
0
Leiomyosarcoma Leiomyosarcoma
1969
Leu et al.
M
40
Thigh
1971
Wilder et at.
M
55
Groin
-
-
M
0 0 0
Ankle skin involved Intraluminal to femoral and iliac veins
Local recurrence, liver 2 yr and death at 4 yr Intraluminal extension 0
keiomyomrf, Sarcoma Fibroleiomyoma “Phlebosarcoma ”
Leiomyosarcoma Leiomyosarcoma
to the thyroid gland in the absence of pulmonary involvement is unusual, although it could have followed metastasis via the vertebral venous plexus (Batson, 1940). These tumours arise from smooth muscle in the media of the blood vessel wall and resemble similar leiomyosarcomas in other sites, for example stomach and uterus. Microscopically the malignant tumours consist of interlacing fascicles of long spindle cells, round cells, or even bizarre giant forms, with cellular polarity maintained in well-differentiated tumours. The nuclei are elongated with blunt ends and one may see myofibrils in the cytoplasm. Palisading of nuclei resembles that seen in neurogenic neoplasms. The atypia and increased number of mitoses per high-power field is indicative of the degree of malignancy. The histology of all three operative specimens in this case is consistent with the diagnosis of primary saphenous vein leiomyosarcoma with distant spread to the thyroid gland and subcutaneous tissue. One should bear
40
E. CROSS AND M. A . HORTON
in mind, however, the possibilities of a spindle cell variant of anaplastic carcinoma of the thyroid and a less likely second primary leiomqiosarcoma developing in the thyroid gland. In this case an independent primary thyroid carcinoma was seriously considered until the appearance of subcutaneous secondary deposits confirming metastasis from the saphenous vein primary tumour. Treatment of malignant lesions in the saphenous vein should consist of wide excision well outside the palpable edge of the mass. However, the diagnosis of malignancy is not often made pre-operatively. A high index of suspicion of unusual lumps may help as does the fact that these venous tumours can usually be excised completely by removing the involved vessel. Deep X-rays or chemotherapy are not thought to be of value. Survival in venous leiomyosarcomas is related to the degree of malignancy of the tumour and to its size. Large masses over 5 cm in diameter are almost invariably malignant. Reference has already been made to the importance of the number of mitotic figures per high-power field. Post-operative local recurrence, being uncommon, usually indicates a poor prognosis. SUMMARY
A case of primary leiomyosarcoma of the greater saphenous vein with metastatic spread to the thyroid gland and subcutaneous tissue is described. The literature of saphenous vein leiomyosarcomas is reviewed. We wish to thank Mr S. G. Nardell for allowing us to publish details of a patient in his care and Drs C. Raeburn and A. G. Stansfeld for helpful criticism. Requests for reprints to M. A. Horton. REFERENCES ADACHI,M., WELLMAN, K. F., AND GARCHIA, R.1969. Metastatic leiomyosarcoma in brain and heart. J. Path., 98, 294. ALLISON, M. F. 1965. Leiomyosarcoma of the femoral vein: report of a case of a child. Clin. Pediatr., 4, 28. AUFRECHT, E. 1868. Ein myom der vena saphena. Virchowe. Arch. Path. Anat., 44, 133. BATSON,0. V. 1940. The function of the vertebral veins and their role in the spread of metastases. Ann. Surg., 112, 138. BORCHARD, V. 1906. Ueber eine von varicen der unterschenkels ausgenhende eigen thumliche geschwulstbildung (Angiosarkom). Arch. f. klin. Chir., 80, 675. CHRISTIANSEN, J. 1964. Maligne tumorer udgaet fra venesystemet. En oversigt og et tilfaelde af leiomyosarkom udgaet fra vena saphena magna. Ugeskr. Laeger., 126,483. DEWEESE,J. A., TERRY, R. AND SCHWARTZ, s. I. 1958. Leiomyoma of greater saphenous vein with preoperative localisation by phlebography. Ann. Surg., 148, 859. DORFMAN, H. D., AND FISCHEL, E. R. 1963. Leiomyoma of the greater saphenous vein. Am. J. Clin. Path., 39, 73. DIJKSTRA, R. 1963. Flebosarcoom. Een geval van primair sarcoom van de vena saphena magna. Ned. T. Geneesk., 107, 81. ECOFFEY, M. 1917. Fibroleiomyoma telangiectasique d'une branche de la veine saphene. Arch. med. exper. et anat. path., 27, 454. HENDRICK, J. W. 1957. Leiomyoma of the thyroid gland. Surgery, 42, 597. KEVORKIAN, J., AND ONTO, D. P. 1973. Leiomyosarcoma of large arteries and veins. Surgery, 73, 390.
GROSS AND HORTON
PLATE IX LEIOMYOSARCOMA OF VEIN
PLAlt
x
LEIOMYOSARCOMA OF VEIN
41
LEU,H. J., AND NIPKOW, P. 1969. Malignant primary vein tumours. Angiologica, 6, 302. SILVERBERG, S. E., AND VIDONE,R. A. 1966. Metastatic tumours in the thyroid. Pacific Medicine and Surgery, 74, 175. SMOUT, M. S., AND FISHER, J. H. 1960. Leiomyosarcoma of saphenous vein. Canad. Med. Ass. J., 83, 1066. STOUT,A. P. 1966. Page 127 in atlas of tumour pathology, 2nd series, fasc. 1, Tumours of the soft tissues, ed. by A. P. Stout. SZASZ, I. J., BARR,R., AND SCOBIE, T. K. 1969. Leiomyosarcoma arising from veins: two cases and a review of the literature on venous neoplasms. Canad. J. Surg., 12, 415.
E. GROSS Surgical Registrar, Whipps Cross Hospital, London, E.11
M. A. HORTON" House Surgeon, Whipps Cross Hospital, London, E.11
PLATESIX
AND
X
LEIOMYOSARCOMAS arising in the venous system are a rare occurence. This paper reports a primary growth arising in the saphenous vein with unusual metastases to the thyroid gland and subcutaneous tissue. CASEREPORT A 46-year-old white man was referred in January 1970 to the out-patient department complaining of a painless lump on the right thigh, present for 2 yr, which had recently begun to enlarge. There was n o history of trauma. His previous medical history was noncontributory. Physical examination revealed a fit, well-nourished adult male with a 5 x 5 cm firm nontender mass in the upper medial right thigh, approximately 15 cm below the inguinal ligament. There was attachment to deep fascia, but not to the overlying skin. The mass did not transilluminate or fluctuate and no enlarged lymph-nodes were palpable. Distally the limb was of normal size and no oedema or varicosities were present. There was no hepatomegaly. The anterior abdominal wall was normal and it was noted that there was no thyroid gland enlargement. Exploration of the right thigh revealed a tumour-like mass growing along the lumen of the saphenous vein and expanding the vessel at the site of the palpable swelling. The portion of the vein containing the tumour was excised and an uneventful recovery ensued. Examination of the specimen revealed an anaplastic spindle-celled tumour of the saphenous vein with the typical histological features of a leiomyosarcoma. The tumour was composed of whorled and interlacing bundles of plain muscle cells with large hyperchromatic nuclei. There were pleomorphic and giant celled areas with a moderate number of mitoses. Differentiation was variable, in parts being quite well differentiated (fig. 1). Almost 3 yr later (January 1973) the patient was re-admitted, having noticed the sudden appearance of a painless swelling in the left side of his neck in the region of the thyroid gland. He had no symptoms suggestive of toxicity or dysphagia and his voice was unchanged. His weight was steady. There was no past or family history of goitre. There was a 3 x 3 cm hard, solitary nodule in the left lobe of the thyroid gland with no retrosternal extension. There was no clinical evidence of toxicity. No enlarged lymph-nodes were palpable and the trachea was central. There was no evidence of local recurrence in the scar on the right thigh. Thyroid function tests confirmed euthyroid status. Chest X-ray showed no abnormalities and X-ray of the thoracic inlet revealed some displacement of the trachea to the right, but no compression or calcification. Received 28 June 1974; accepted 4 July 1974.
* Present address: Department of Pathology, St Bartholomew's Hospital, London, E.C.l I. PATH.-VOL.
116 (1975)
37
38
E. GROSS AND M. A . HORTON
A near total thyroidectomy was performed through a collar incision. There was a stony-hard nodule occupying most of the left lobe of the thyroid gland while the isthmus and the right lobe were small and not macroscopically involved with tumour. Post-operatively the vocal cords were moving normally, he was never hypocalcaemic and was discharged on a maintenance dose of L-thyroxine. Histological examination of the thyroid specimen revealed a much more pleomorphic tumour, with increased fibrosis modifying the histological features. Fairly well differentiated plain muscle cells mingled with spindle-celled and giant-celled areas. Mitoses were numerous and often bizarre. The thyroid follicles were encircled by growth and atrophied. This was considered to be consistent with a secondary deposit of leiomyosarcoma in the thyroid gland (fig. 2). The patient was then treated with Telecobalt irradiation and the 15 meV linear accelerator, receiving 6500 r to the anterior neck and cervical node regions. Regular follow-up revealed no evidence of local recurrence until October 1973 when it was noted that he had two small subcutaneous nodules in the left hypochondrium. An excision biopsy was performed and histology confirmed fairly well-differentiated, occasionally anaplastic, secondary leiomyosarcoma nearer in structure to the primary turnour (fig. 3). At his most recent follow-up visit the patient remains clinically well with no sign of recurrence at any of the three sites. His chest X-ray is clear, there is no hepatomegally and his E.S.R. is within normal limits.
DISCUSSION Reviews of the world literature on primary vascular leiomyosarcomas have all agreed on the rarity of the lesions-some 86 reports since the first valid case of leiomyosarcoma in the inferior vena cava was reported by Per1 in 1871 (cited by Kevorkian and Cento, 1973). Although the inferior vena cava seems to be particularly involved (33 reports), the next most common sites are the femoral and long saphenous veins. Kevorkian and Cento (1973) discovered reports of eight primary leiomyosarcomas in large systemic arteries. The majority of cases involving the saphenous vein have been reported since De Weese’s case in 1958, and this probably reflects an increased awareness of this uncommon tumour rather than an altered incidence. Most of the lesions have been found in the proximal part of the saphenous vein (eight out of 14 reports) in the groin or thigh, particularly in the more recently published cases. The features of previously recorded saphenous vein smooth muscle tumours are summarised in the table. Certain characteristics distinguish saphenous vein from other venous leiomyosarcomas. The sex ratio (M :F; 9 :5 ) shows a male predominance compared with the well-recognised but unexplained excess of female cases involving the inferior vena cava. Venous obstruction leading to varicose veins or leg oedema is less common the more distal the site of the tumour, in practice only occurring in lesions affecting the saphenofemoral junction. We did not detect evidence of excessive collateral venous circulation in our patient. There is little tendency to intraluminal growth, although this is noted in the inferior vena cava where the tumour may float free within the blood stream. Metastatic spread is uncommon from the smaller vessels, the majority being slow growing and localised, invading only surrounding tissues or adjacent skin. The distribution of secondaries, with thyroid and subcutaneous deposits, in this case is unusual in that the majority of metastasising leiomyosarcomas involve the lungs and liver predominantly and other sites infrequently. Malignant mesenchymal neoplasms of the thyroid gland are rare except for
39
LEIOMYOSARCOMA OF VEIN
lymphomas, the most common type being fibrosarcoma. Primary smooth muscle tumours arising in the thyroid gland are extremely rare, only single cases of leiomyoma (Hendrick 1957) and leiomyosarcoma (Adachi et d.,1969) having been described. Secondary deposits in the thyroid gland are common in epithelial malignancy (Silverberg and Vidone, 1966) but unusual in sarcomas on non-lymphoid origin, this case being the first report of a secondary leiomysarcomatous deposit in the thyroid gland. Spread from a remote primary site TABLE Primary smooth muscle tumours arising in the saphenous vein __
reported
Author
Sex
Age
Site
Spread
Histology
- -
1868 1906 1917 1919
Aufrecht Borchard Ecoffey Van Ree
M
1958 I960 1963 1963
M F
23 44 40 42
Ankle Ankle Leg Leg
De Weese et al.
M
54
Saphenofemoral jtn
F M M
76 59 56
Thigh Thigh Knee
0 0 0
1964 1965
Smout et al. Dijkstra Dorfman et al. Christiansen Allison
Leiomyoma ( ?) low-grade sarcoma Leiomyosarcoma Leiomyosarcoma Leiomyosarcoma
F F
64 3
0 0
Leiomyosarcoma Leiomyosarcoma
1966 1969
stout Szasz et al.
F M
50 68
Thigh Saphenofemoral jtn Branch Thigh
0
Leiomyosarcoma Leiomyosarcoma
1969
Leu et al.
M
40
Thigh
1971
Wilder et at.
M
55
Groin
-
-
M
0 0 0
Ankle skin involved Intraluminal to femoral and iliac veins
Local recurrence, liver 2 yr and death at 4 yr Intraluminal extension 0
keiomyomrf, Sarcoma Fibroleiomyoma “Phlebosarcoma ”
Leiomyosarcoma Leiomyosarcoma
to the thyroid gland in the absence of pulmonary involvement is unusual, although it could have followed metastasis via the vertebral venous plexus (Batson, 1940). These tumours arise from smooth muscle in the media of the blood vessel wall and resemble similar leiomyosarcomas in other sites, for example stomach and uterus. Microscopically the malignant tumours consist of interlacing fascicles of long spindle cells, round cells, or even bizarre giant forms, with cellular polarity maintained in well-differentiated tumours. The nuclei are elongated with blunt ends and one may see myofibrils in the cytoplasm. Palisading of nuclei resembles that seen in neurogenic neoplasms. The atypia and increased number of mitoses per high-power field is indicative of the degree of malignancy. The histology of all three operative specimens in this case is consistent with the diagnosis of primary saphenous vein leiomyosarcoma with distant spread to the thyroid gland and subcutaneous tissue. One should bear
40
E. CROSS AND M. A . HORTON
in mind, however, the possibilities of a spindle cell variant of anaplastic carcinoma of the thyroid and a less likely second primary leiomqiosarcoma developing in the thyroid gland. In this case an independent primary thyroid carcinoma was seriously considered until the appearance of subcutaneous secondary deposits confirming metastasis from the saphenous vein primary tumour. Treatment of malignant lesions in the saphenous vein should consist of wide excision well outside the palpable edge of the mass. However, the diagnosis of malignancy is not often made pre-operatively. A high index of suspicion of unusual lumps may help as does the fact that these venous tumours can usually be excised completely by removing the involved vessel. Deep X-rays or chemotherapy are not thought to be of value. Survival in venous leiomyosarcomas is related to the degree of malignancy of the tumour and to its size. Large masses over 5 cm in diameter are almost invariably malignant. Reference has already been made to the importance of the number of mitotic figures per high-power field. Post-operative local recurrence, being uncommon, usually indicates a poor prognosis. SUMMARY
A case of primary leiomyosarcoma of the greater saphenous vein with metastatic spread to the thyroid gland and subcutaneous tissue is described. The literature of saphenous vein leiomyosarcomas is reviewed. We wish to thank Mr S. G. Nardell for allowing us to publish details of a patient in his care and Drs C. Raeburn and A. G. Stansfeld for helpful criticism. Requests for reprints to M. A. Horton. REFERENCES ADACHI,M., WELLMAN, K. F., AND GARCHIA, R.1969. Metastatic leiomyosarcoma in brain and heart. J. Path., 98, 294. ALLISON, M. F. 1965. Leiomyosarcoma of the femoral vein: report of a case of a child. Clin. Pediatr., 4, 28. AUFRECHT, E. 1868. Ein myom der vena saphena. Virchowe. Arch. Path. Anat., 44, 133. BATSON,0. V. 1940. The function of the vertebral veins and their role in the spread of metastases. Ann. Surg., 112, 138. BORCHARD, V. 1906. Ueber eine von varicen der unterschenkels ausgenhende eigen thumliche geschwulstbildung (Angiosarkom). Arch. f. klin. Chir., 80, 675. CHRISTIANSEN, J. 1964. Maligne tumorer udgaet fra venesystemet. En oversigt og et tilfaelde af leiomyosarkom udgaet fra vena saphena magna. Ugeskr. Laeger., 126,483. DEWEESE,J. A., TERRY, R. AND SCHWARTZ, s. I. 1958. Leiomyoma of greater saphenous vein with preoperative localisation by phlebography. Ann. Surg., 148, 859. DORFMAN, H. D., AND FISCHEL, E. R. 1963. Leiomyoma of the greater saphenous vein. Am. J. Clin. Path., 39, 73. DIJKSTRA, R. 1963. Flebosarcoom. Een geval van primair sarcoom van de vena saphena magna. Ned. T. Geneesk., 107, 81. ECOFFEY, M. 1917. Fibroleiomyoma telangiectasique d'une branche de la veine saphene. Arch. med. exper. et anat. path., 27, 454. HENDRICK, J. W. 1957. Leiomyoma of the thyroid gland. Surgery, 42, 597. KEVORKIAN, J., AND ONTO, D. P. 1973. Leiomyosarcoma of large arteries and veins. Surgery, 73, 390.
GROSS AND HORTON
PLATE IX LEIOMYOSARCOMA OF VEIN
PLAlt
x
LEIOMYOSARCOMA OF VEIN
41
LEU,H. J., AND NIPKOW, P. 1969. Malignant primary vein tumours. Angiologica, 6, 302. SILVERBERG, S. E., AND VIDONE,R. A. 1966. Metastatic tumours in the thyroid. Pacific Medicine and Surgery, 74, 175. SMOUT, M. S., AND FISHER, J. H. 1960. Leiomyosarcoma of saphenous vein. Canad. Med. Ass. J., 83, 1066. STOUT,A. P. 1966. Page 127 in atlas of tumour pathology, 2nd series, fasc. 1, Tumours of the soft tissues, ed. by A. P. Stout. SZASZ, I. J., BARR,R., AND SCOBIE, T. K. 1969. Leiomyosarcoma arising from veins: two cases and a review of the literature on venous neoplasms. Canad. J. Surg., 12, 415.
