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Spindle Cell Lipoma of the Orbit
Spindle Cell Lipoma of the Orbit George B. Bartley, M.D., R. Patrick Yeatts, M.D., James A. Garrity, M.D, George M. Farrow, M.D., and R. Jean Campbell, M.D. A spindle cell lipoma was partially removed from the left orbit of a 27-year-old man. Computed tomography showed a large, mildly enhancing, primarily intraconal mass. The circumscribed, nonencapsulated mass was composed of mature adult lipocytes, spindle cells, and capillaries. The spindle cells lacked a basal lamina and contained a single enlongated nucleus. Cells containing osmiophilic material were rounded with nucleus displaced to one margin. Because of the tumor's size and proximity to vital structures, total excision was not possible. Such tumors are more frequent in the subcutaneous tissue of the shoulder and posterior aspect of the neck. This benign lesion may be mistaken for other spindle cell tumors, including liposarcoma, angiolipoma, neurilemoma, and hemangiopericytoma. SPINDLE CELL LIPOMA is a distinct variant of lipoma in which spindle cells replace normal fat. 1,2 Although the disorder is relatively common in the posterior aspect of the neck and shoulder region of middle-aged men.l-" its occurrence in the orbit is extremely rare. We are aware of only one previous case report. 3
Visual acuity was R.E.: 20/20 and L.E.: 20/25. Pupillary reflexes, confrontation visual fields, intraocular pressure by applanation, and the results of color plate testing were normal. Results of examination of the right eye and adnexa were unremarkable. The left globe was displaced inferiorly and temporally, and 6 mm of proptosis was measured with Krahn exophthalmometry (Fig. 1). A firm, rubbery, nontender mass was palpable along the entire superior aspect of the left orbit. Moderate resistance to retropulsion of the left globe was noted. There were no audible bruits, discoloration of the eyelids, or change in eye or eyelid appearance with the Valsalva maneuver. Although no diplopia was noted by the patient in primary gaze, mild restriction of the left eye in upgaze resulted in double vision. Slit-lamp findings for the left eye were normal. Ophthalmoscopy disclosed choroidal folds coursing through the posterior pole as well as indentation of the superior aspect of the left globe by the orbital tumor. Results of a medical examination and laboratory tests were within normal limits. Computed tomography of the orbit outlined a large, mild-
Case Report A 27-year-old man was referred here with a seven-year history of "fullness" in the left upper eyelid. His personal and family medical histories were noncontributory.
Accepted for publication June 19, 1985. From the Department of Ophthalmology (Drs. Bartley, Yeatts, Garrity, and Campbell) and the Section of Surgical Pathology (Drs. Farrow and Campbell), Mayo Clinic and Foundation, Rochester, Minnesota. Presented in part at the Theobald Society meeting, San Antonio, Texas, March 29, 1985. This study was supported in part by Research to Prevent Blindness, Inc. Reprint requests to R. Jean Campbell, M.D., Mayo Clinic, Rochester, MN 55905.
©AMERICAN JOURNAL OF OPHTHALMOLOGY
100:605--609,
Fig. 1 (Bartley and associates). Inferotemporal displacement of left globe. Note fullness of left upper eyelid.
OCTOBER,
1985
605
606
October, 1985
AMERICAN JOURNAL OF OPHTHALMOLOGY
Fig. 2 (Bartley and associates). Computed tomography shows large, primarily intraconal mass in left orbit. Note superior and nasal extension. Left orbital roof is eroded but intact. Note areas of decreased attenuation within the tumor.
ly enhancing, primarily intraconal mass that extended superiorly and medially within the left orbit. The orbital roof was eroded but intact. Radiolucent areas, thought to represent cystic degeneration or orbital fat, were noted within the tumor (Fig. 2). No intracranial or sinus abnormalities were identified. A left superior orbitotomy was performed. The tumor was tan, partially circumscribed, closely associated with the orbital structures, and well vascularized. Frozen-section examination of a biopsy specimen of the lesion suggested spindle cell lipoma or neurilemoma. Because of the size of the tumor and its proximity to vital structures, a debulking procedure (rather than a total excision) was performed, and a mass measuring 1.6 x 1.3 x x 0.6 em was removed. Histopathologic examination demonstrated a circumscribed, nonencapsulated mass composed of a mixture of mature adult lipocytes, spindle cells, and many capillaries (Fig. 3). The spindle cells were generally of uniform appearance with regular bipolar tapering outlines and were aligned in sheets. Pleomorphism, atypia, and mitotic figures were noticeably absent. The nuclei of the spindle cells were single and elongated (Fig. 4). Areas of prominent vascularity were interspersed among the spindle cells and mature lipocytes. The vessels in these areas varied in size and outline, and many
Fig. 3 (Bartley and associates). Fibrovascular fatty tissue (hematoxylin and eosin, x 40).
appeared sinusoidal (Fig. 5). There was no necrosis. Some areas showed positive staining with Alcian blue (pH 2.5), which digested with testicular hyaluronidase. Giemsa stain showed a sparse infiltration with mast cells. Material from the deparaffinized block was examined with electron microscopy. Thin sections were cut and stained with uranyl acetate and lead citrate and studied with an electron microscope. The spindle cells lacked a basal lamina and contained a single elongated nucleus, the membranes of which showed indentation (Fig. 6). A small nucleolus was observed in
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Fig. 4 (Bartley and associates). Mature lipocytes and uniform spindle-shaped cells. There is no evidence of atypia or mitotic figures (hematoxylin and eosin, x 160).
Vol. 100, No.4
Spindle Cell Lipoma of the Orbit
607
displaced to one margin (Fig. 7). These cells were surrounded in part by a basal lamina. Most fat cells contained numerous lipid droplets; a limiting membrane bounded the larger droplets. The amorphous ground matrix contained collagen fibrils with characteristic cross-banding. The endothelial cells of the vessels showed autolytic changes of organelles, but no fat droplets were observed within the cytoplasm. The basal lamina and the pericytes of the larger vessels appeared to be normal (Fig. 6). Fig. 5 (Bartley and associates). Areas of prominent vascularity. Vessels vary in size and some appear sinusoidal. Matrix is composed of benign spindle cells (hematoxylin and eosin, x 400).
most cells, and the chromatin was fairly evenly dispersed. The organelles were poorly preserved. Lipid material within fibroblasts was not observed. Cells containing osmiophilic material tended to be rounded with the nucleus
Discussion Although benign lipomas are common in subcutaneous tissue and in the retroperitoneal and mediastinal spaces, their presence in the orbit is rare. A Mayo Clinic study by Henderson and Farrow' of 764 orbital tumors included only two lipomas. In 1975, Enzinger and Harvey! described
Fig. 6 (Bartley and associates). Spindle cell (arrowhead) lacks basal lamina. Nucleus is indented and shows a distinct nucleolus. Note normal vessel wall at lower right (x 1,500).
608
October, 1985
AMERICAN JOURNAL OF OPHTHALMOLOGY
..e-.
•
' . . '
Fig. 7 (Bartley and associates). Mature lipocytes surrounded in part by a basal lamina. Numerous fat droplets, some membrane-bound, are present within cytoplasm (x 4,500).
spindle cell lipomas as a histologically distinct variant of lipoma in which mature fat is replaced by collagen-forming spindle cells.! The tumor is typically found in the posterior aspect of the neck and shoulder areas of men (91 % of cases) between the ages of 45 and 65 years (mean age, 56 years)Y Although lipomas grossly appear as normal, homogeneous, yellow adipose tissue, spindle cell lipomas may look variegated because of the gray-white areas of spindle cell proliferation. These lesions are usually circumscribed and scantly vascularized; in a few cases, blood vessels may be so abundant that the tumor resembles a neoplasm of vascular origin. Interestingly, only five of the 114 spindle cell lipomas originally described by Enzinger and Harvey! displayed prominent vascular channels, yet both our case and that described by Johnson and Linn" exhibited this feature. The microscopic appearance is variable; some tumors are composed primarily of spindle cells but others consist predominantly of lipocytes. The spindle cells show no cellular pleomorphism and are uniformly arranged
in a matrix of collagen fibrils or a mucoid Alcian-blue-positive ground substance; these features allow the important distinction from a liposarcoma. Nuclear palisading may cause confusion with neurilemomas, leiomyomas, or fibrous histiocytomas. The immunostains 5100 and Factor VIII were weakly positive in obvious vascular areas. Ulex europaeus binding was shown with erythrocytes as well as endothelial cells. The cross-reactivity of Ulex for blood group antigens and endothelial surface antigens obviates its specificity for the latter. The only other tissue that shows blood group expression is epithelium, and spindle cell lipoma is clearly not of epithelial origin. The material for electron microscopic examination was obtained from a deparaffinized block and therefore was not of optimum quality. Nevertheless, the cell features present were consistent with those described by others. l ,2,5.8 Computed tomographic findings for orbital spindle cell lipoma have not been previously reported. The variegated appearance caused by
Vol. 100, No.4
Spindle Cell Lipoma of the Orbit
cystic degeneration or the adipose component of the tumor is rarely observed in other wellcircumscribed intraconal orbital lesions, such as cavernous hemangioma or neurogenic tumors. Although our patient was younger than those in whom spindle cell lipomas are usually found, his gender was typical. The gross and microscopic appearances of the tumor were similar to those reported elsewhere.I" but it had the somewhat unusual presence of extensive vascularization, as in the case described by Johnson and Linn." Previous reports'" indicated that circumscription of the tumor may allow cure by simple total excision. Our patient illustrated that orbital involvement may be extensive, thus precluding total removal of the mass without radical dissection. ACKNOWLEDGMENT
F. M. Enzinger of the Armed Forces Institute of Pathology reviewed the histopathologic sections.
609
References 1. Enzinger, F. M., and Harvey, D. A.: Spindle cell lipoma. Cancer 36:1852, 1975. 2. Enzinger, F. M., and Weiss, S. W.: Soft Tissue Tumors. St. Louis, C. v. Mosby, 1983, pp. 211-214. 3. Johnson, B. L., and Linn, J. G., Jr.: Spindle cell lipoma of the orbit. Arch. Ophthalmol. 97:133, 1979. 4. Henderson, J. M., and Farrow, G. M.: Orbital Tumors, 2nd ed. New York, B. C. Decker/ThiemeStratton, Inc., 1980, pp. 252 and 253. 5. Angervall, L., Dahl, 1., Kindblom, L.-G., and Save-Soderbergh, J.: Spindle cell lipoma. Acta Path01. Microbiol. Scand. 84:477, 1976. 6. Bolen, J. W., and Thorning, D.: Spindle-cell lipoma. A clinical, light- and electron-microscopical study. Am. J. Surg. Pathol. 5:435, 1981. 7. Kim, Y. H., and Reiner, L.: Ultrastructure of lipoma. Cancer 50:102, 1982. 8. McDaniel, R. K., Newland, J. R., and Chiles, D. G.: Intraoral spindle cell lipoma. Case report with correlated light and electron microscopy. Oral Surg. 57:52, 1984.
Visual acuity was R.E.: 20/20 and L.E.: 20/25. Pupillary reflexes, confrontation visual fields, intraocular pressure by applanation, and the results of color plate testing were normal. Results of examination of the right eye and adnexa were unremarkable. The left globe was displaced inferiorly and temporally, and 6 mm of proptosis was measured with Krahn exophthalmometry (Fig. 1). A firm, rubbery, nontender mass was palpable along the entire superior aspect of the left orbit. Moderate resistance to retropulsion of the left globe was noted. There were no audible bruits, discoloration of the eyelids, or change in eye or eyelid appearance with the Valsalva maneuver. Although no diplopia was noted by the patient in primary gaze, mild restriction of the left eye in upgaze resulted in double vision. Slit-lamp findings for the left eye were normal. Ophthalmoscopy disclosed choroidal folds coursing through the posterior pole as well as indentation of the superior aspect of the left globe by the orbital tumor. Results of a medical examination and laboratory tests were within normal limits. Computed tomography of the orbit outlined a large, mild-
Case Report A 27-year-old man was referred here with a seven-year history of "fullness" in the left upper eyelid. His personal and family medical histories were noncontributory.
Accepted for publication June 19, 1985. From the Department of Ophthalmology (Drs. Bartley, Yeatts, Garrity, and Campbell) and the Section of Surgical Pathology (Drs. Farrow and Campbell), Mayo Clinic and Foundation, Rochester, Minnesota. Presented in part at the Theobald Society meeting, San Antonio, Texas, March 29, 1985. This study was supported in part by Research to Prevent Blindness, Inc. Reprint requests to R. Jean Campbell, M.D., Mayo Clinic, Rochester, MN 55905.
©AMERICAN JOURNAL OF OPHTHALMOLOGY
100:605--609,
Fig. 1 (Bartley and associates). Inferotemporal displacement of left globe. Note fullness of left upper eyelid.
OCTOBER,
1985
605
606
October, 1985
AMERICAN JOURNAL OF OPHTHALMOLOGY
Fig. 2 (Bartley and associates). Computed tomography shows large, primarily intraconal mass in left orbit. Note superior and nasal extension. Left orbital roof is eroded but intact. Note areas of decreased attenuation within the tumor.
ly enhancing, primarily intraconal mass that extended superiorly and medially within the left orbit. The orbital roof was eroded but intact. Radiolucent areas, thought to represent cystic degeneration or orbital fat, were noted within the tumor (Fig. 2). No intracranial or sinus abnormalities were identified. A left superior orbitotomy was performed. The tumor was tan, partially circumscribed, closely associated with the orbital structures, and well vascularized. Frozen-section examination of a biopsy specimen of the lesion suggested spindle cell lipoma or neurilemoma. Because of the size of the tumor and its proximity to vital structures, a debulking procedure (rather than a total excision) was performed, and a mass measuring 1.6 x 1.3 x x 0.6 em was removed. Histopathologic examination demonstrated a circumscribed, nonencapsulated mass composed of a mixture of mature adult lipocytes, spindle cells, and many capillaries (Fig. 3). The spindle cells were generally of uniform appearance with regular bipolar tapering outlines and were aligned in sheets. Pleomorphism, atypia, and mitotic figures were noticeably absent. The nuclei of the spindle cells were single and elongated (Fig. 4). Areas of prominent vascularity were interspersed among the spindle cells and mature lipocytes. The vessels in these areas varied in size and outline, and many
Fig. 3 (Bartley and associates). Fibrovascular fatty tissue (hematoxylin and eosin, x 40).
appeared sinusoidal (Fig. 5). There was no necrosis. Some areas showed positive staining with Alcian blue (pH 2.5), which digested with testicular hyaluronidase. Giemsa stain showed a sparse infiltration with mast cells. Material from the deparaffinized block was examined with electron microscopy. Thin sections were cut and stained with uranyl acetate and lead citrate and studied with an electron microscope. The spindle cells lacked a basal lamina and contained a single elongated nucleus, the membranes of which showed indentation (Fig. 6). A small nucleolus was observed in
t
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(..
..
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,1 ~ ..
1,')0
/,.,.,
~(
'.
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/'
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.,
_ Ji-d
Fig. 4 (Bartley and associates). Mature lipocytes and uniform spindle-shaped cells. There is no evidence of atypia or mitotic figures (hematoxylin and eosin, x 160).
Vol. 100, No.4
Spindle Cell Lipoma of the Orbit
607
displaced to one margin (Fig. 7). These cells were surrounded in part by a basal lamina. Most fat cells contained numerous lipid droplets; a limiting membrane bounded the larger droplets. The amorphous ground matrix contained collagen fibrils with characteristic cross-banding. The endothelial cells of the vessels showed autolytic changes of organelles, but no fat droplets were observed within the cytoplasm. The basal lamina and the pericytes of the larger vessels appeared to be normal (Fig. 6). Fig. 5 (Bartley and associates). Areas of prominent vascularity. Vessels vary in size and some appear sinusoidal. Matrix is composed of benign spindle cells (hematoxylin and eosin, x 400).
most cells, and the chromatin was fairly evenly dispersed. The organelles were poorly preserved. Lipid material within fibroblasts was not observed. Cells containing osmiophilic material tended to be rounded with the nucleus
Discussion Although benign lipomas are common in subcutaneous tissue and in the retroperitoneal and mediastinal spaces, their presence in the orbit is rare. A Mayo Clinic study by Henderson and Farrow' of 764 orbital tumors included only two lipomas. In 1975, Enzinger and Harvey! described
Fig. 6 (Bartley and associates). Spindle cell (arrowhead) lacks basal lamina. Nucleus is indented and shows a distinct nucleolus. Note normal vessel wall at lower right (x 1,500).
608
October, 1985
AMERICAN JOURNAL OF OPHTHALMOLOGY
..e-.
•
' . . '
Fig. 7 (Bartley and associates). Mature lipocytes surrounded in part by a basal lamina. Numerous fat droplets, some membrane-bound, are present within cytoplasm (x 4,500).
spindle cell lipomas as a histologically distinct variant of lipoma in which mature fat is replaced by collagen-forming spindle cells.! The tumor is typically found in the posterior aspect of the neck and shoulder areas of men (91 % of cases) between the ages of 45 and 65 years (mean age, 56 years)Y Although lipomas grossly appear as normal, homogeneous, yellow adipose tissue, spindle cell lipomas may look variegated because of the gray-white areas of spindle cell proliferation. These lesions are usually circumscribed and scantly vascularized; in a few cases, blood vessels may be so abundant that the tumor resembles a neoplasm of vascular origin. Interestingly, only five of the 114 spindle cell lipomas originally described by Enzinger and Harvey! displayed prominent vascular channels, yet both our case and that described by Johnson and Linn" exhibited this feature. The microscopic appearance is variable; some tumors are composed primarily of spindle cells but others consist predominantly of lipocytes. The spindle cells show no cellular pleomorphism and are uniformly arranged
in a matrix of collagen fibrils or a mucoid Alcian-blue-positive ground substance; these features allow the important distinction from a liposarcoma. Nuclear palisading may cause confusion with neurilemomas, leiomyomas, or fibrous histiocytomas. The immunostains 5100 and Factor VIII were weakly positive in obvious vascular areas. Ulex europaeus binding was shown with erythrocytes as well as endothelial cells. The cross-reactivity of Ulex for blood group antigens and endothelial surface antigens obviates its specificity for the latter. The only other tissue that shows blood group expression is epithelium, and spindle cell lipoma is clearly not of epithelial origin. The material for electron microscopic examination was obtained from a deparaffinized block and therefore was not of optimum quality. Nevertheless, the cell features present were consistent with those described by others. l ,2,5.8 Computed tomographic findings for orbital spindle cell lipoma have not been previously reported. The variegated appearance caused by
Vol. 100, No.4
Spindle Cell Lipoma of the Orbit
cystic degeneration or the adipose component of the tumor is rarely observed in other wellcircumscribed intraconal orbital lesions, such as cavernous hemangioma or neurogenic tumors. Although our patient was younger than those in whom spindle cell lipomas are usually found, his gender was typical. The gross and microscopic appearances of the tumor were similar to those reported elsewhere.I" but it had the somewhat unusual presence of extensive vascularization, as in the case described by Johnson and Linn." Previous reports'" indicated that circumscription of the tumor may allow cure by simple total excision. Our patient illustrated that orbital involvement may be extensive, thus precluding total removal of the mass without radical dissection. ACKNOWLEDGMENT
F. M. Enzinger of the Armed Forces Institute of Pathology reviewed the histopathologic sections.
609
References 1. Enzinger, F. M., and Harvey, D. A.: Spindle cell lipoma. Cancer 36:1852, 1975. 2. Enzinger, F. M., and Weiss, S. W.: Soft Tissue Tumors. St. Louis, C. v. Mosby, 1983, pp. 211-214. 3. Johnson, B. L., and Linn, J. G., Jr.: Spindle cell lipoma of the orbit. Arch. Ophthalmol. 97:133, 1979. 4. Henderson, J. M., and Farrow, G. M.: Orbital Tumors, 2nd ed. New York, B. C. Decker/ThiemeStratton, Inc., 1980, pp. 252 and 253. 5. Angervall, L., Dahl, 1., Kindblom, L.-G., and Save-Soderbergh, J.: Spindle cell lipoma. Acta Path01. Microbiol. Scand. 84:477, 1976. 6. Bolen, J. W., and Thorning, D.: Spindle-cell lipoma. A clinical, light- and electron-microscopical study. Am. J. Surg. Pathol. 5:435, 1981. 7. Kim, Y. H., and Reiner, L.: Ultrastructure of lipoma. Cancer 50:102, 1982. 8. McDaniel, R. K., Newland, J. R., and Chiles, D. G.: Intraoral spindle cell lipoma. Case report with correlated light and electron microscopy. Oral Surg. 57:52, 1984.