within the medial rectus muscle

Transcription

1 British Journal of Ophthalmology, 1983, 67, Case report of granular cell myoblastoma arising within the medial rectus muscle P. MORIARTY, A. GARNER, AND J. E. WRIGHT From the Orbital Clinic, Moorfields Eye Hospital, and the Department of Pathology, Institute of Ophthalmology, London SUMMARY A rare case of granular cell myoblastoma is reported in a 37-year-old man where the tumour was situated within the medial rectus muscle. Histological, cytochemical and ultrastructural examination showed it to have features typical of granular cell myoblastoma. It also reacted with chorioembryonic antigen antisera, a sign of primitive cell origin. The findings add further weight to the idea of the histiogenesis of these tumours from primitive mesenchymal cells. Since Abrikossoff' first described granular cell myoblastoma (GCM) in 1926 this tumour has been found in many parts of the body, most commonly the tongue. Cases have been reported involving the lids2" eyebrow,5 lacrimal sac,6 and the ciliary body.' Orbital GCM is rare, and only 1I cases have previously been recorded This case is presented for 3 reasons: first, the rarity of granular cell myoblastoma in the orbit; secondly, the unusual presenting feature of visual obscuration related to eye position; and lastly the good recovery of eye movements and visual acuity following the resection of a large tumour from within the orbit, particularly as it was within one of the extraocular muscles. Case report HISTORY A 37-year-old man complained of mild pain around his left frontal area for 12 months. For the latter 8 months of this time he had also noted diplopia on laevoversion and increasing visual distortion in the left eye. As well as diplopia colour vision was reduced, and he had visual obscurations after prolonged laevoversion which cleared on regaining the primary position. At the time of the presenting symptoms he had a daughter of 51/2 years who was undergoing treatment for cerebral astrocytoma. The patient's father had died from cerebral glioma. Correspondence to Mr P. Moriarty, FRCS, Moorfields Eye Hospital, City Road, London ECIV 2PD. PHYSICAL SIGNS On examination visual acuity was 6/5 unaided in the right eye and 6/12 unaided in the left eye. Extraocular movements showed slight limitation of abduction and some left incycloduction and left sursumduction, with left over right in the primary position. The left eye was proptosed 4 mm axially and displaced 2 mm laterally (Fig. 1). Anisocoria was present with the left pupil larger than the right. On prolonged laevoversion an afferent pupillary defect was noted which disappeared on regaining the primary position. Fundal examination showed left optic disc swelling, with venous engorgement and choroidal folds running through the macular area. Fig. 1 Left proptosis and lateral displacement of the globe at the time ofpresentation. 17

2 18 P. Moriarty, A. Garner, and J. E. Wright Fig. 2 Fig. 3 Axial and coronal CTstudies showing a large radiodense mass in the medial side of the orbit, indistinguishable Figs. 2, 3 from the medial rectus muscle. INVESTIGATIONS Plain radiographs of the orbit were normal. CT scans showed a large cigar-shaped mass which was indistinguishable from the medial rectus muscle and displayed contrast enhancement (Figs. 2, 3). Carotid angiography was performed, but no abnormal circulation could be detected. Fluorescein angiography showed a reduced blood flow in the retinal circulation when the left eye was held in abduction (Fig. 4). TREATMENT A lateral orbitotomy was performed. The medial rectus muscle was approached across the intraconal space, and the optic nerve was displaced downwards. A large pale tumour was found in the medial rectus muscle. The muscle was split, longitudinally on its inner surface, posteriorly between the 2 branches of the third nerve supplying the muscle and anteriorly to its insertion on the globe. The tumour was shelled out from the muscle fibres within which it lay and was totally removed. Postoperatively vision in the left eye was reduced to 6/18 and adduction was absent. After 10 weeks the vision had returned to 6/6, with disappearance of the choroidal folds, adduction of the eye had almost fully recovered, and there was no proptosis or displacement. After 6 months he had equal vision in 44 xax Fig. 4 Fluorescein angiogram taken in aduction, primary position ofgaze, and abduction showing relative dilatation ofthe retinal veins on abduction. t.x;ytis'.' 9AX ff~~~~~~~~~~~~~~~~~

3 Case report of granular cell myoblastoma arising within the medial rectus muscle T7: - e- lig. 5 rig. e Patient3 months after orbitotomy showing absence ofproptosis andfull return ofmedial rectus muscle function. Figs. 5, 6 both eyes (6/5) and diplopia only in extreme laevoversion, there being a 20% reduction in adduction and abduction. After 18 months adduction had totally recovered, but there was an approximate 10% reduction in abduction in the left eye. There is no sign of recurrence (Figs. 5, 6). PATHOLOGY The surgical specimen measured 27 x 15 x 17 mm and was hard, pale grey, and encapsulated. Light microscopy showed long strap-like cells, which tended to form a syncytium, within a connective tissue stroma (Fig. 7). The nuclei were small, and mitotic figures were not seen. Frozen sections stained for lipid showed a markedly granular staining pattern (Fig. 8). Histochemical analysis of the granules showed them to consist of glycoprotein, with some bound lipid, indicating a probable lysosomal origin. Electron microscopy showed prominent basal laminae, organelles packed with granules, some myelin figures, and areas of degenerate mitochondria; long-spaced collagen was also present (Figs. 9, 10). The cytoplasm of the tumour cells showed weak but unmistakable affinity for antibody to carcinoembryonic antigen by an immunoperoxidase technique. This implies that the cells are primitive and relatively undifferentiated.'7 18 Discussion Abrikossoff s original assertion that the tumour arises from striated muscle cells has been challenged. Evidence has been put forward for a histiocytic origin either as a hyperplasia, ' a granulomatous response to parasites,20 or as a storage disorder.2' Others have drawn attention to similarities between granular cell 19 Fig. 7 Histological section showing strap-like cells with granular cytoplasm tending to forn a syncytium. Between the tumour cells there is a variable amount of fibrous connective tissue. (Haematoxylin and eosin, x270).

4 20 Fig. 8 Frozen sections reveal this lipid content of the granules within the tumour cell cytoplasm. (Oil red 0, x270). myoblastoma and neural tissue, suggesting an affinity with neurofibroma,2223 perineural fibroblastoma,24 or Schwann cells.2526 More recently, owing to the great similarity between the ultrastructure of schwannomas and granular cell myoblastoma, it has been postulated that both may arise from a pluripotential mesenchymal cell. Sobel et al. 27 put forward a schema to show the evolution of fibroblasts, smooth muscle cells, and granular histiocytes at sites of muscle trauma from such cells. This evidence, coupled with the positive chorioembryonic antigen antisera test, suggests that there is a strong case for assigning the Fig. 9 The cytoplasmic granules are membrane-bound and contain fine amorphous material of variable density. (EM, xj0000)....a.,4 P. Moriarty, Garner, and J. E. Wright lk..'...*y. genesis of both schwannomas and granular cell myoblastoma to a primitive pluripotential cell line. Furthermore, the finding that granular cell myoblastoma is similar to recognised tumours of Schwann cells and melanocytes in containing S-100 protein28is putative evidence of a neural crest origin. The location of the tumour in the present case within the medial rectus muscle could be taken to support a myoblastic origin, but in the absence of confirmatory evidence from histochemical and ultrastructural study this conclusion is not really warranted. A presentation of visual obscuration caused by the

5 Case report of granular cell myoblastoma arising within the medial rectus muscle mechanical effects of the tumour in different positions of gaze is unusual, though we have seen this with 2 other patients at Moorfields who have had optic nerve meningiomas. In this case as in the others it could be shown that the visual symptoms were due to the reduction of blood flow in the retinal circulation on holding the eye in the abducted position, the mechanical action of the tumour in this position causing compression of the optic nerve and its vascular supply. After the operation there were no signs of fluctuating circulation with the eye position. The almost total lack of postoperative problems in this patient was due to a wide exposure by means of a lateral orbitotomy approach and a careful microsurgical dissection carried out under hypotensive anaesthesia. We can foresee no other approach which could give such a good result considering the difficult anatomical site of the lesion. Previously this tumour has been reported fixed to the extraocular muscles9 '5 and to the optic nerve,8 but, as far as we are aware, it is unique for this neoplasm to be contained within an extraocular muscle. According to the literature this tumour is usually benign, and only 2 reports of malignancy in the orbit have been published.2 16 One of these 16 was a metastasis from a primary granular cell myoblastoma of the ovary which metastasised to the eyelid. The other, a primary orbital tumour,2 recurred after exenteration and spread regionally and metastatically Fig. 10 The intervening stroma of the tumour included long-spacing as well as regular collagen fibrils. (EM, x10 700). over a 2-year period. At present our reported case has been followed up for 18 months with no signs of recurrence. Our thanks are due to Mr Anthony Booth, FRCS. neurosurgeon to the Walsgrove County Hospital, who referred this case. Thanks are also due to Miss Heather Lucas for tvping the manuscript. References I Abrikossoff A. Uber Myome ausgehend von der quergestreiften willkurlichen Muskulatur. Virchows Arch (Pathol Anat) 1926; 260: Dunnington JH. Granular cell myoblastoma of the orbit. Arch Ophthalmol 1948; 40: Timm G, Timmell H. Zum myoblastenmyom am Auge. Klin Monastsbl Augenheilkd 1966; 148: Blodi FC. Unusual myogenic tumors around the eye. Arch Ophthalmol 1956; 56: Dermv P, Morax PV. La tumeur a cellules granuleuses (tumeur d'abnkossoff) dans sa localisation palpebro-orbitaire. Ann Oculist (Paris) 1966; 199: von Bahr G. A case of myoblastic myoma of the lacrimal sac. Acta Ophthalmol (Kbh) 1938; 16: Cunha SL, Lobo FG. Granular cell myoblastoma of the anterior uvea. Br J Ophthalmol 1966; 50: Chaves E. Oliveira AM, Arnaud AC. Retrobulbar granular cell myoblastoma. Br J Ophthalmol 1972; 56: Morgan LR, Fryer MP. Granular cell myoblastoma of the eye: case report. Plast Reconstr Surg 1969; 43: Drummond JW, Hall DL, Steen WH, Samuel A, Maxey SA. Granular cell tumor (myoblastoma) of the orbit. Arch Ophthalmol 1979; 97: IMorgan G. Granular cell myoblastoma of the orbit. Arch Ophthalmol 1976; 94:

6 22 12 Gonzalez-Almarez G, de Buen S, Tsutsumi V. Granular cell tumor (myoblastoma) of the orbit. Am J Ophthalnol 1975; 79: Sakonaki Y. A case of intraorbital myoblastoma. J Clin Ophthalmol 1963; 17: Oabayashi K, Yamada Y, Kozaki M. Granular cell myoblastoma in the orbit. Folia Ophthalmol Jpn 1969; 20: Dhermy P, Reynes M, Clay C, Morax S, Paszynski V. Tumeur a cellules granuleuses de l'orbit. J Fr Ophtalmol 1980; 3: Powell EG. Granular cell myoblastoma. Arch Pathol 1946; 42: Shousha S, Lyssiotis T. Granular cell myoblastoma: positive staining for carcinoembryonic antigen. J Clin Pathol 1979; 32: Robertson AJ, McIntosh W, Lamont P, Guthrie W. Malignant granular cell tumour (myoblastoma) of the vulva: report of a case and review of the literature. Histopathology 1981; 5: Leroux R, Delarue J. Sur trois cas de tumeurs a cellules granuleuses de la cavite buccale. Bull Cancer (Paris) 1939; 28: Guillino P. Sui cosidetti 'tumori de mioblasti' interpretati come P. Moriarty, A. Gamer, and J. E. Wright granulomi di probabile origine parasitaria. Tumori 1946; 20: Azzopardi JG. Histogenesis of the granular-cell 'myoblastoma'. J Pathol Bacteriol 1956; 71: Fust JA, Custer RP. On the neurogenesis of so-called granular cell myoblastoma. Am J Clin Pathol 1949; 19: Bangle R Jr. Morphological and histochemical study of granular cell myoblastoma. Cancer 1952; 5: Pearse AGE. Histogenesis of granular-cell myoblastoma (? granular-cell perineural fibroblastoma). J Pathol Bacteriol 1950; 62: Grancis JC, Komorowski RA, Kuzma JF. Granular cell myoblastoma. Cancer 1970; 25: Sobel HJ, Marquet E, Avrin E, Schwarz R. Granular cell myoblastoma. An electron microscopic and cytochemical study illustrating the genesis of granules and ageing of myoblastoma cells. Am J Pathol 1971; 65: Sobel HJ, Avrin E, Marquet E, Schwartz R. Reactive granular cells in sites of trauma. Am J Clin Pathol 1974; 61: Stefansson K, Wollmann R, Jerkovic M. S-100 protein in softtissue tumours derived from Schwann cells and melanocytes. Am J Pathol 1982; 106: Br J Ophthalmol: first published as /bjo on 1 January Downloaded from on 9 January 2019 by guest. Protected by copyright.