Acta path. microbiol. scand. Sect. A, 84: 477 -487, 1976
SPINDLE CELL LIPOMA L. ANGERVAI.I., I. DAHI.,L.-G. KINDBLOM and J. SAVE-SODERBERGIi Department of Pathology 11, Sahlgren's Hospital, Goteborg, Sweden
Angervall, L., Dahl, I., Kindblom, L.-G. & Save-Soderbergh, J. Spindle cell lipoma. Acta path. microbiol. scand. Sect. A, 84: 477-487, 1976. A clinical, light- and electronmicroscopic study of 14 patients with spindle cell lipoma is presented. Spindle cell lipoma is considered to be a distinctive lipomatous tumour histologically characterized by a mixture of fat cells and fibroblast-like spindle cells, ultrastructurally similar to fibroblasts, in a matrix with varying amounts of collagen and mucosubstances. T h e tumours showed a predominance for elderly men and all but one were situated in the posterior neck, shoulder region or upper back. T h e tumours varied between 1 and 9 cm, with a median value of 5 cm, in the widest diameter and were entirely or almost entirely situated in the subcutaneous tissue. A follow-up study of 11 patients, observed for 1-25 years, confirmed that the clinical course is benign. T h e differential diagnosis is discussed and it is emphasized that spindle cell lipoma is easily misinterpreted as sarcoma. Three tumours showed a pronounced nuclear polymorphism without mitotic activity, thought to be regressive in nature. 'The cellular change in these three tumours are presumed to be analogous with those in so called ancient neurilemmoma and therefore the name ancient spindle cell lipoma is proposed for the polymorphic spindle cell lipomas. Key words: Spindle cell lipoma; lipoma; soft tissue tumour; pseudosarcomatous lesion.
I,. Angervall, Department of Pathology, Vasa Hospital, S-411 33 Goteborg, Sweden.
Received 19.vi.76
Accepted 19.vi.76
Spindle cell lipoma is a recently described type of soft tissue tumour characterized histologically by a mixture of fat cells and fibroblast-like spindle cells in a matrix of collagen and mucoid material. This lipomatous tumour has frequently been misinterpreted as liposarcoma and other soft tissue sarcomas (Enzinger & Harvey 1975). Experience, however, of 114 cases presented by Enzinger and Harvey has shown the tumour to be perfectly benign, occurring predominantly in the shoulder-neck area of elderly males. This paper presents a clinico-pathological study of 14 patients with spindle cell lipoma including an ultrastructural study of formalinfixed tumour tissue in 3 cases. Three of the '(I
Acta path.
miciobiol. wand. Sect. A. 84. 6
tumours showed pronounced nuclear polymorphism without mitotic activity presumed to be analogous with the nuclear changes in so called ancient neurilemmoma.
MATERIAL AND METHODS Two out of 14 cases were obtained from a Swedish series comprising some 800 cases of malignant soft tissue tumours reported to the Swedish Cancer Registry during a 6-year-period ( 1958-1963). Three cases were selected after reviewing various soft tissue lesions recorded in the Department of Pathology, Sahlgren's Hospital, Goteborg. Four tumours were sent to us for consultations from other pathological laboratories in Sweden. The additional 5 cases, examined in the period from 1972 and onwards, were diagnosed as spindle cell lipoma. Dr. Enzinger, chief of the soft tissue division,
477
‘TAB1.E 1. Clinical Features in 1 4 Patients w i t h S p i n d l e Cell Lipornu
Size Case no.
1 2
:< 4 5 ti 7 8 9 10 11 12 13 14
Age (Years) 76 50 63 ti7 43 44 24 59 51 67 63 31 74 61
Sex
Anatomical distribution
M M M M F M F
Posterior neck Posterior neck Upper back Shoulder, right Posterior neck Posterior neck Right thigh, mrdial part Shoulder, right Shoulder, right Shoulder, right Posterior neck Forehead Posterior neck Posterior neck
M M
M M M M M
Armed Forces Institute of Pathology, Washington, D.C., was consulted in the first of these cases and thereby drew our attention to this tiimour entity, later descrihed by Enringer & Harrwy (1975). ‘l’he operative specimens were fixed in 4 per cent formaldehyde solution and emhedded in paraffin. Five micron thick sections were stained according to the haematoxylin-van Gimon method and with haematoxylin and eosin. Gordon’s and Sweet’s silver impregnation was used for the demonstration of reticulin fibres, and Weigert’s elastin method for studying elastic tissne in tnmour \-easel$. Alcian blue (Chroma-Gesellschaft) and toluidine blue stains were used at 2 different pHs, p H 2.5 and 0.5 and 4.0 and 0.5, reypectively, for the examination of glucose-aminoglycans (nomenclature according to Jeanlor 1960) as descrihed previously ( A n g e r v a l l e t al. 1973, K i n d b l o n i & Angeruall 1975). ‘I‘hese stains were performed with and without prior treatment of the sections with testiciilar hyaluronidase (hyalnronidase from bovine testes, type IV, Sigma) ( L e p p i K: S t o u m r d 1965). Staining was performed according to S c o t t & Dorling (1965) at p H 5.6 \sith 0.05 per cent Alcian blue in 0.025 M acetate buffer, with the addition of increasing concentrations of MgCI, in order to determine the “critical electrolyte concentration” ( C E C ) of the dye-polymer hinding in the mucoid material. T h e following series of MgCI,concentrations was used: 0.0 M, 0.025 M, 0.05 M, 0.1 M, 0.25 M, 0.35 M, 0.45 M, 0.55 M, 0.65 M, 0.75 M, 0.85 M and 1.0 M . Staining time was 16 hours. In 3 cases, small pieces of trimour tissue were ernliedded in glycol metachrylate and 1-2 micron thick sections were stained according to the haema-
478
(cm) 6 x 4 2.5 ~ 5x4 3x3 5x5 2x1.5 9x8 8 x 5 ~ 3 8 x 5 x 2.5 5x4 2.5 x 2.5
2x2 2x2 1.2 x 1 3.5 x 2.5
Follow-up period (years) 4 25 4 2 8
2 12 1 12 2 12
SPINDLE CELL LIPOMA L. ANGERVAI.I., I. DAHI.,L.-G. KINDBLOM and J. SAVE-SODERBERGIi Department of Pathology 11, Sahlgren's Hospital, Goteborg, Sweden
Angervall, L., Dahl, I., Kindblom, L.-G. & Save-Soderbergh, J. Spindle cell lipoma. Acta path. microbiol. scand. Sect. A, 84: 477-487, 1976. A clinical, light- and electronmicroscopic study of 14 patients with spindle cell lipoma is presented. Spindle cell lipoma is considered to be a distinctive lipomatous tumour histologically characterized by a mixture of fat cells and fibroblast-like spindle cells, ultrastructurally similar to fibroblasts, in a matrix with varying amounts of collagen and mucosubstances. T h e tumours showed a predominance for elderly men and all but one were situated in the posterior neck, shoulder region or upper back. T h e tumours varied between 1 and 9 cm, with a median value of 5 cm, in the widest diameter and were entirely or almost entirely situated in the subcutaneous tissue. A follow-up study of 11 patients, observed for 1-25 years, confirmed that the clinical course is benign. T h e differential diagnosis is discussed and it is emphasized that spindle cell lipoma is easily misinterpreted as sarcoma. Three tumours showed a pronounced nuclear polymorphism without mitotic activity, thought to be regressive in nature. 'The cellular change in these three tumours are presumed to be analogous with those in so called ancient neurilemmoma and therefore the name ancient spindle cell lipoma is proposed for the polymorphic spindle cell lipomas. Key words: Spindle cell lipoma; lipoma; soft tissue tumour; pseudosarcomatous lesion.
I,. Angervall, Department of Pathology, Vasa Hospital, S-411 33 Goteborg, Sweden.
Received 19.vi.76
Accepted 19.vi.76
Spindle cell lipoma is a recently described type of soft tissue tumour characterized histologically by a mixture of fat cells and fibroblast-like spindle cells in a matrix of collagen and mucoid material. This lipomatous tumour has frequently been misinterpreted as liposarcoma and other soft tissue sarcomas (Enzinger & Harvey 1975). Experience, however, of 114 cases presented by Enzinger and Harvey has shown the tumour to be perfectly benign, occurring predominantly in the shoulder-neck area of elderly males. This paper presents a clinico-pathological study of 14 patients with spindle cell lipoma including an ultrastructural study of formalinfixed tumour tissue in 3 cases. Three of the '(I
Acta path.
miciobiol. wand. Sect. A. 84. 6
tumours showed pronounced nuclear polymorphism without mitotic activity presumed to be analogous with the nuclear changes in so called ancient neurilemmoma.
MATERIAL AND METHODS Two out of 14 cases were obtained from a Swedish series comprising some 800 cases of malignant soft tissue tumours reported to the Swedish Cancer Registry during a 6-year-period ( 1958-1963). Three cases were selected after reviewing various soft tissue lesions recorded in the Department of Pathology, Sahlgren's Hospital, Goteborg. Four tumours were sent to us for consultations from other pathological laboratories in Sweden. The additional 5 cases, examined in the period from 1972 and onwards, were diagnosed as spindle cell lipoma. Dr. Enzinger, chief of the soft tissue division,
477
‘TAB1.E 1. Clinical Features in 1 4 Patients w i t h S p i n d l e Cell Lipornu
Size Case no.
1 2
:< 4 5 ti 7 8 9 10 11 12 13 14
Age (Years) 76 50 63 ti7 43 44 24 59 51 67 63 31 74 61
Sex
Anatomical distribution
M M M M F M F
Posterior neck Posterior neck Upper back Shoulder, right Posterior neck Posterior neck Right thigh, mrdial part Shoulder, right Shoulder, right Shoulder, right Posterior neck Forehead Posterior neck Posterior neck
M M
M M M M M
Armed Forces Institute of Pathology, Washington, D.C., was consulted in the first of these cases and thereby drew our attention to this tiimour entity, later descrihed by Enringer & Harrwy (1975). ‘l’he operative specimens were fixed in 4 per cent formaldehyde solution and emhedded in paraffin. Five micron thick sections were stained according to the haematoxylin-van Gimon method and with haematoxylin and eosin. Gordon’s and Sweet’s silver impregnation was used for the demonstration of reticulin fibres, and Weigert’s elastin method for studying elastic tissne in tnmour \-easel$. Alcian blue (Chroma-Gesellschaft) and toluidine blue stains were used at 2 different pHs, p H 2.5 and 0.5 and 4.0 and 0.5, reypectively, for the examination of glucose-aminoglycans (nomenclature according to Jeanlor 1960) as descrihed previously ( A n g e r v a l l e t al. 1973, K i n d b l o n i & Angeruall 1975). ‘I‘hese stains were performed with and without prior treatment of the sections with testiciilar hyaluronidase (hyalnronidase from bovine testes, type IV, Sigma) ( L e p p i K: S t o u m r d 1965). Staining was performed according to S c o t t & Dorling (1965) at p H 5.6 \sith 0.05 per cent Alcian blue in 0.025 M acetate buffer, with the addition of increasing concentrations of MgCI, in order to determine the “critical electrolyte concentration” ( C E C ) of the dye-polymer hinding in the mucoid material. T h e following series of MgCI,concentrations was used: 0.0 M, 0.025 M, 0.05 M, 0.1 M, 0.25 M, 0.35 M, 0.45 M, 0.55 M, 0.65 M, 0.75 M, 0.85 M and 1.0 M . Staining time was 16 hours. In 3 cases, small pieces of trimour tissue were ernliedded in glycol metachrylate and 1-2 micron thick sections were stained according to the haema-
478
(cm) 6 x 4 2.5 ~ 5x4 3x3 5x5 2x1.5 9x8 8 x 5 ~ 3 8 x 5 x 2.5 5x4 2.5 x 2.5
2x2 2x2 1.2 x 1 3.5 x 2.5
Follow-up period (years) 4 25 4 2 8
2 12 1 12 2 12
