Histopatholog!! 1990. 17, 165-I82
BRIEF R E P O R T
Dermatofibrosarcoma protuberans with areas resembling giant cell fibroblastoma: report of two cases A . REHAM & C. D. M. FLETCHER* lnstittrte of Puthology, University of Gruz School of’ Mdicine, Graz, Austriu m i *l)epurtriwnt of Histopatholog;{, St Thomas’s Hospital Medicul School ( U M D S ) , London. U K Date of submission 6 November 1989 Accepted for publication 12 january 1990
Two cases of otherwise typical dermatofibrosarcoma protuberans showing a gradual transition to areas with the characterstic appearances of giant cell tibroblastoma are described. Both lesions were excised from the trunk of adults, These provide further evidence of the putative close relationship between these two neoplastic entities.
Clinicopathological findings Out of a total of 128 cases of dermatofibrosarcoma protuberans on file in the Department of Histopathology at St Thomas’s Hospital. two cases with areas resembling giant cell fibroblastoma have been identified. Case 1 was a 1 0 cm recurrent mass in the skin of the back of a 3 3year-old male. Case 2 was a ‘lemon-sized’ cutaneous
Keywords: dermatofibrosarcoma protuberans, tibroblastoma, soft tissue, skin, tumour
Introduction Dermatofibrosarcoma protuberans and giant cell tibroblastoma are generally regarded as distinctive soft tissue neoplasms, the former arising predominantly in young to middle-aged adults and the latter being most common in childhood’.’. While both are very prone to local recurrence, only dermatofibrosarcoma protuberans has been reported to occasionally metastasize. In conventional cases they usually bear no great histological similarities. The rather confusing suggestion that giant cell tibroblastoma might represent a juvenile form ofdermatotibrosarcoma protuberans was first mentioned (without any supporting evidence) in 1985 The basis for this hypothesis emerged in the latest edition of Enzinger 8r Weiss’s text‘, when the authors very briefly mentioned (but did not illustrate) the existence of occasional cases of dermatofibrosarcoma protuberans with areas similar to giant cell fibroblastoma in their deep aspect. We wish to document two such cases which would support a possible close relationship between these two entities.
’.
Address for correspondence: I)r C.U.M.I:letcher. Department 01 Histopathology. St Thomas’s Hospital Medical School. I,ondon. SEI 7EH. UK.
Figure I . Case 2: typical monomorphic appearance o f dermatofibrosarcoma protuberans inliltrating subcutaneous fat, x 1 0 0 .
165
166
Brief reports
mass from the umbilical region of a 30-year-old female, which had been present for one year. Unfortunately no further follow-up is available in either case. Conventional haematoxylin and eosin-stained sections in each case revealed that the bulk of each tumour had the typical appearances of a dermatofibrosarcoma protuberans, consisting of bland fibroblast-like cells showing scattered mitoses and arranged in a monotonous storiform pattern (Figure 1). In both cases, this appearance merged imperceptibly into smaller foci showing a totally different pattern, quite characteristic of giant cell fibroblastoma (Figure 2). In these areas, bland spindle cells and multinucleate giant cells were dispersed in a copious myxoid stroma, within which typical irregular ‘angiectoid’spaces lined by similar cells could be identified (Figure 3). In case 1, the giant cell fibroblastoma-like component was situated at the deep (subcutaneous) margin, while in case 2 it occupied a protuberant nodule in the papillary dermis. Immunohistochemically, tumour cells in both components labelled only with vimentin. Staining for S-100, desmin, EMA and keratin was negative. In 11 cases of giant cell fibroblastoma currently no from the Same has been identified in which a focal transition to typical dermatofibrosarcoma protuberans is evident.
Figure 2. Case 1 : gradual transition from dermatotibrosarcoma (top)to more hypocellular. myxoid area resembling giant cell fibroblastoma is evident in this rather fragmented portion of tissue. x 25.
Figure 3 . The giant cell fibroblastoma-like areas show typical so-called angiectoid spaces and multinucleate giant cells in a case 1 and b case 2 . a x 90. b x 225.
Brief reports
Discussion At present, dermatofibrosarcoma protuberans is conventionally regarded as a fibrohistiocytic neoplasm of intermediate malignancy, while giant cell fibroblastoma is seen as a benign fibroblastic lesion, possibly related to the fibromatoses. The two cases described herein would, however, support the concept that these two entities are closely related, particularly since their respective histological patterns are so distinctive and are not readily amenable to alternative interpretation. Further similarities between the two lesions are common anatomical distribution, exclusively superficial location and a tendency to local recurrence. Metastasis is rare in dermatofibrosarcoma protuberans and has never been reported in giant cell fibroblastoma. The suggestion that giant cell fibroblastoma is simply a juvenile variant of dermatofibrosarcoma protuberans would seem to be an over-simplification since we have seen histologicallypure cases of both typical dermatofibrosarcoma protuberans in infancy and childhood (even congenitally) and of giant cell fibroblastoma in adulthood. Although the precise basis for their relatioriship remains uncertain, it
167
seems likely that both are histogenetically-related tumours of fibroblasts showing different patterns of differentiation which, on occasion, may be mixed, presumably in response to subtle differences in environmental or host-derived influences.
Acknowledgements C.D.M.F. is a Cancer Research Campaign Senior Clinical Kesearch Fellow.
References 1 . Pletcher CDM. Evans Bl, Macartney JC. Smith N. Wilson Jones E.
McKee I’H. 1)errnatolibrosarcoma protuberans: a clinicopathological and imrnunohistochernical study with a review of the literature. Histoputhofog~j1985: 9; 921-938. 2. Fletcher CDM. Giant cell fibroblastoma of soft tissue: a clinicopathological and imrnunohistochcrnical study. Histoputhologg 1988: 13: 499-508. 3 . (’hung EB. Pitfalls in diagnosing benign soft tissue tumors in infancy and childhood. I’cithol. Annu. 19x5; 2; 323-386. 4. linxinger PM. Weiss SW. Giant cell fibroblastoma. In So/t Tissup Tunrors. 2nd ed. St I m i s : C.V. Mosby. 1988: 184-185.
BRIEF R E P O R T
Atypical ‘pseudosarcomatous’ variant of cutaneous benign fibrous histiocytoma: report of eight cases A. BEHAM & C .D.M. FLETCHER* Institute of Pathology, University of Gruz School of Medicine, Graz, Austriu and *Dopartrnent of Histoputhology, St Thomas’s Hospital Medical School ( U M D S ) , London, U K Date of submission 2 0 November 1989 Accepted for publication 2 February 1990
Eight cases of benign cutaneous tibrous histiocytoma containing scattered, bizarre. pleomorphic cells of multinucleate or histiocyte-like type are described. All arose in adults and four had originally been diagnosed as sarcomas. Lesions of this type are not well-known and merit wider recognition in order to avoid inappropriate treatment. Differential diagnosis principally includes
Address for correspondence: Dr C.I).M.Fletcher. Department ol Histopathology. St Thomas’s Hospital Medical School. 1,ondon. SEl 7EH. [JK.
atypical fibroxanthoma and pleomorphic malignant fibrous histiocytoma. Keywords: fibrous histiocytoma, pseudosarcoma, skin
Introduction The majority of cutaneous benign fibrous histiocytomas (dermatofibromas) pose no diagnostic difficulty. However, occasional cases may show sufficient pleomorphism, albeit in a minority of cells, to prompt a mistaken diagnosis of malignancy. Such lesions have previously
BRIEF R E P O R T
Dermatofibrosarcoma protuberans with areas resembling giant cell fibroblastoma: report of two cases A . REHAM & C. D. M. FLETCHER* lnstittrte of Puthology, University of Gruz School of’ Mdicine, Graz, Austriu m i *l)epurtriwnt of Histopatholog;{, St Thomas’s Hospital Medicul School ( U M D S ) , London. U K Date of submission 6 November 1989 Accepted for publication 12 january 1990
Two cases of otherwise typical dermatofibrosarcoma protuberans showing a gradual transition to areas with the characterstic appearances of giant cell tibroblastoma are described. Both lesions were excised from the trunk of adults, These provide further evidence of the putative close relationship between these two neoplastic entities.
Clinicopathological findings Out of a total of 128 cases of dermatofibrosarcoma protuberans on file in the Department of Histopathology at St Thomas’s Hospital. two cases with areas resembling giant cell fibroblastoma have been identified. Case 1 was a 1 0 cm recurrent mass in the skin of the back of a 3 3year-old male. Case 2 was a ‘lemon-sized’ cutaneous
Keywords: dermatofibrosarcoma protuberans, tibroblastoma, soft tissue, skin, tumour
Introduction Dermatofibrosarcoma protuberans and giant cell tibroblastoma are generally regarded as distinctive soft tissue neoplasms, the former arising predominantly in young to middle-aged adults and the latter being most common in childhood’.’. While both are very prone to local recurrence, only dermatofibrosarcoma protuberans has been reported to occasionally metastasize. In conventional cases they usually bear no great histological similarities. The rather confusing suggestion that giant cell tibroblastoma might represent a juvenile form ofdermatotibrosarcoma protuberans was first mentioned (without any supporting evidence) in 1985 The basis for this hypothesis emerged in the latest edition of Enzinger 8r Weiss’s text‘, when the authors very briefly mentioned (but did not illustrate) the existence of occasional cases of dermatofibrosarcoma protuberans with areas similar to giant cell fibroblastoma in their deep aspect. We wish to document two such cases which would support a possible close relationship between these two entities.
’.
Address for correspondence: I)r C.U.M.I:letcher. Department 01 Histopathology. St Thomas’s Hospital Medical School. I,ondon. SEI 7EH. UK.
Figure I . Case 2: typical monomorphic appearance o f dermatofibrosarcoma protuberans inliltrating subcutaneous fat, x 1 0 0 .
165
166
Brief reports
mass from the umbilical region of a 30-year-old female, which had been present for one year. Unfortunately no further follow-up is available in either case. Conventional haematoxylin and eosin-stained sections in each case revealed that the bulk of each tumour had the typical appearances of a dermatofibrosarcoma protuberans, consisting of bland fibroblast-like cells showing scattered mitoses and arranged in a monotonous storiform pattern (Figure 1). In both cases, this appearance merged imperceptibly into smaller foci showing a totally different pattern, quite characteristic of giant cell fibroblastoma (Figure 2). In these areas, bland spindle cells and multinucleate giant cells were dispersed in a copious myxoid stroma, within which typical irregular ‘angiectoid’spaces lined by similar cells could be identified (Figure 3). In case 1, the giant cell fibroblastoma-like component was situated at the deep (subcutaneous) margin, while in case 2 it occupied a protuberant nodule in the papillary dermis. Immunohistochemically, tumour cells in both components labelled only with vimentin. Staining for S-100, desmin, EMA and keratin was negative. In 11 cases of giant cell fibroblastoma currently no from the Same has been identified in which a focal transition to typical dermatofibrosarcoma protuberans is evident.
Figure 2. Case 1 : gradual transition from dermatotibrosarcoma (top)to more hypocellular. myxoid area resembling giant cell fibroblastoma is evident in this rather fragmented portion of tissue. x 25.
Figure 3 . The giant cell fibroblastoma-like areas show typical so-called angiectoid spaces and multinucleate giant cells in a case 1 and b case 2 . a x 90. b x 225.
Brief reports
Discussion At present, dermatofibrosarcoma protuberans is conventionally regarded as a fibrohistiocytic neoplasm of intermediate malignancy, while giant cell fibroblastoma is seen as a benign fibroblastic lesion, possibly related to the fibromatoses. The two cases described herein would, however, support the concept that these two entities are closely related, particularly since their respective histological patterns are so distinctive and are not readily amenable to alternative interpretation. Further similarities between the two lesions are common anatomical distribution, exclusively superficial location and a tendency to local recurrence. Metastasis is rare in dermatofibrosarcoma protuberans and has never been reported in giant cell fibroblastoma. The suggestion that giant cell fibroblastoma is simply a juvenile variant of dermatofibrosarcoma protuberans would seem to be an over-simplification since we have seen histologicallypure cases of both typical dermatofibrosarcoma protuberans in infancy and childhood (even congenitally) and of giant cell fibroblastoma in adulthood. Although the precise basis for their relatioriship remains uncertain, it
167
seems likely that both are histogenetically-related tumours of fibroblasts showing different patterns of differentiation which, on occasion, may be mixed, presumably in response to subtle differences in environmental or host-derived influences.
Acknowledgements C.D.M.F. is a Cancer Research Campaign Senior Clinical Kesearch Fellow.
References 1 . Pletcher CDM. Evans Bl, Macartney JC. Smith N. Wilson Jones E.
McKee I’H. 1)errnatolibrosarcoma protuberans: a clinicopathological and imrnunohistochernical study with a review of the literature. Histoputhofog~j1985: 9; 921-938. 2. Fletcher CDM. Giant cell fibroblastoma of soft tissue: a clinicopathological and imrnunohistochcrnical study. Histoputhologg 1988: 13: 499-508. 3 . (’hung EB. Pitfalls in diagnosing benign soft tissue tumors in infancy and childhood. I’cithol. Annu. 19x5; 2; 323-386. 4. linxinger PM. Weiss SW. Giant cell fibroblastoma. In So/t Tissup Tunrors. 2nd ed. St I m i s : C.V. Mosby. 1988: 184-185.
BRIEF R E P O R T
Atypical ‘pseudosarcomatous’ variant of cutaneous benign fibrous histiocytoma: report of eight cases A. BEHAM & C .D.M. FLETCHER* Institute of Pathology, University of Gruz School of Medicine, Graz, Austriu and *Dopartrnent of Histoputhology, St Thomas’s Hospital Medical School ( U M D S ) , London, U K Date of submission 2 0 November 1989 Accepted for publication 2 February 1990
Eight cases of benign cutaneous tibrous histiocytoma containing scattered, bizarre. pleomorphic cells of multinucleate or histiocyte-like type are described. All arose in adults and four had originally been diagnosed as sarcomas. Lesions of this type are not well-known and merit wider recognition in order to avoid inappropriate treatment. Differential diagnosis principally includes
Address for correspondence: Dr C.I).M.Fletcher. Department ol Histopathology. St Thomas’s Hospital Medical School. 1,ondon. SEl 7EH. [JK.
atypical fibroxanthoma and pleomorphic malignant fibrous histiocytoma. Keywords: fibrous histiocytoma, pseudosarcoma, skin
Introduction The majority of cutaneous benign fibrous histiocytomas (dermatofibromas) pose no diagnostic difficulty. However, occasional cases may show sufficient pleomorphism, albeit in a minority of cells, to prompt a mistaken diagnosis of malignancy. Such lesions have previously
