Dermatofibrosarcoma non-protuberans: description and report of five cases of a morpheaform variant of dermatofibrosarcoma

Atrophic dermatofibrosarcoma protuberans: Two case reports and literature review

Dermatofibrosarcoma protuberans is a rare, locally aggressive, slowly growing cutaneous fibroblastic sarcoma with a high recurrence rate and low metastatic potential. Atrophic dermatofibrosarcoma protuberans is a rare variant usually presents as atrophic plaques, easily neglected and misdiagnosed as benign lesions by patients and dermatologists. Here we report two cases of atrophic dermatofibrosarcoma protuberans, one of which was accompanied by pigment, and review other cases have been reported in the literature. Understanding the most up-to-date literature and early identification of these dermatofibrosarcoma protuberans variants can help clinicians avoid delayed diagnosis and improve prognosis.

Rare Variants of Dermatofibrosarcoma Protuberans: Clinical, Histologic, and Molecular Features and Diagnostic Pitfalls

Dermatofibrosarcoma protuberans (DFSP) is a dermal malignant mesenchymal tumor. Most variants are associated with a high risk of local recurrence and a low risk of metastasis. The classic histomorphology of this tumor is made up of uniform, spindle-shaped cells, arranged in a storiform pattern. Tumor cells characteristically infiltrate the underlying subcutis in a honeycomb pattern. Less common variants of DFSP have been identified: myxoid, pigmented, myoid, granular cell, sclerosing, atrophic, and fibrosarcomatous. Only the fibrosarcomatous variant has been shown to differ significantly from classic DFSP in terms of clinical outcome; fibrosarcomatous DFSP has been shown to be associated with a greater risk of local recurrence and metastatic potential than classic DFSP. However, the other variants may pose diagnostic difficulty as they resemble other types of spindle cell neoplasms, especially in small biopsy specimens. This article reviews the clinical, histologic, and molecular features of DFSP variants, as well as possible pitfalls in their diagnosis and how to resolve them.

Atrophic Dermatofibrosarcoma Protuberans with Eosinophilic Infiltration

Dermatofibrosarcoma protuberans (DFSP) is a rare, locally aggressive spindle cell mesenchymal tumor arising in the dermis, with low metastatic potential. The most commonly affected sites are the trunk and proximal extremities; rarely are acral sites involved. Atrophic DFSP is a rare form of DFSP, that is morphologically different but histologically similar to DFSP. It commonly affects young adults between the ages of 20 to 50 years. The current management strategy for atrophic DFSP is surgical excision with long-term follow-up to detect any recurrence. Only one known case of atrophic DFSP with eosinophilic infiltration is what makes our case an exceptionally rare presentation.

Atrophic dermatofibrosarcoma protuberans: a clinicopathological study of 16 cases

We present a case series of atrophic dermatofibrosarcoma protuberans (DFSP) to further characterise its clinical and pathological features. Sixteen cases were enrolled in the study. There were five males and 11 females with a median age of 28 years. The vast majority occurred in the trunk (12/16, 75%), whereas a minority involved the upper limb or limb gird (2/16, 12.5%), and head and neck region (2/16, 12.5%). The most common presentation was a depressed plaque-like lesion with a greyish-red to purplish-blue colour. Histologically, the lesion was dermal-based consisting of monomorphous spindle cells arranged in parallel fascicles with focal areas displaying storiform architecture. In addition, one case showed remarkable hyalinisation of the matrix, two cases contained scattered pigmented dendritic cells and one case had admixed giant cell fibroblastoma-like component, respectively. The diagnosis was confirmed by immunohistochemical study, and by further fluorescence in situ hybridisation analysis in six cases. Follow-up thus far has revealed a relatively low rate of local recurrence (1/10, 10%). Familiarity with the distinctive clinical and pathological features of atrophic DFSP helps avoid misdiagnosis. Like a classical DFSP, morphological variants can also occur in an atrophic DFSP, including pigmented, sclerosing and hybrid subtypes, albeit rare.

Current Update on the Molecular Biology of Cutaneous Sarcoma: Dermatofibrosarcoma Protuberans

OPINION STATEMENT

Cutaneous sarcoma is a group of malignant mesenchymal tumors primarily involving the dermis, and it is characterized by extreme clinicopathological heterogeneity. Although its occurrence rate is rare, dermatofibrosarcoma protuberans (DFSP) is one of the most common types of dermal sarcoma. DFSP grows slowly and tends to relapse locally after inadequate resection. There are various histological variants of DFSP tumors and it often mimics benign lesions such as dermatofibroma and scar, which make accurate diagnosis difficult and delayed, and some cases progress to the stage where the tumor is unresectable. Recent advancements in cancer genetics and molecular biology methods have elucidated the COL1A1-PDGFB fusion gene, some novel fusion gene variants and pathways related to DFSP pathogenesis that have resulted in the evolution of cutaneous sarcoma diagnosis and treatment. For example, some clinical studies have confirmed the efficacy of imatinib methylate, an αPDGFR-targeted therapy for unresectable or metastatic DFSP. The present review summarizes recent updates in DFSP research, diagnostics, and treatment.

Dermatofibrosarcoma protuberans: clinicopathologic presentation in Nigerians

Introduction

Dermatofibrosarcoma protuberance (DFSP) is in general a rare low grade malignant sarcoma and possesses a tendency for local recurrence. It has a site predilection for the trunk. Occurrence in the facial area is extremely rare. Ample knowledge of its clinical, histological and biologic characteristics is vital for accurate and prompt recognition.

Methods

Over 13 years, clinicohistologic information of cases was retrieved. Histological and immunohistochemical re-evaluation were performed to re-confirm diagnosis. Data collected and analyzed with SPSS Statistics version 20 were presented as frequency tables, charts and proportions as appropriate.

Results

Of 191 soft tissue sarcomas, a total of 28 cases were diagnosed as DFSP (14.7%). Facial types occurred in 3 cases (1.6%). Tumour had age and site predilections for the 4^th decade and trunk respectively. There was an equal gender distribution among cases. Most common clinical presentation was in form of painless protruding nodular mass. General histologic presentation revealed cellular lesions composed of spindle to oval neoplastic cells arranged in a storiform pattern. Mitotic figures were rare. All cases showed positive expressions to CD34.

Conclusion

Facial DFSP is rare among Nigerians. Its clinical appearance may mimic other common benign lesions of the head and neck region often resulting in misdiagnoses. A comprehensive knowledge of its clinical and histologic presentations and biologic behavior, combined with its identification with the aid of advanced histologic and radiographic techniques results in prompt confirmatory diagnosis. Appropriate treatment should include adequate surgical excision techniques combined with adjuvant radiotherapy or chemotherapy.

Guidelines for Diagnosis and Treatment of Cutaneous Sarcomas: Dermatofibrosarcoma Protuberans

Sarcomas comprise a broad group of tumors, many of whose biological behavior and aggressiveness differ from one type to another. The therapeutic approach is generally multidisciplinary and often complex. Developments in surgical and oncological dermatology during the last few decades have positioned dermatologists as specialists in the diagnosis and treatment of skin cancer. The aim of this article is to review the main soft tissue sarcomas that typically affect the skin. Dermatofibrosarcoma protuberans is a low-grade malignant sarcoma. It exhibits slow-growth, is locally invasive, and has low metastatic potential (<3%). Mohs micrographic surgery is the treatment of choice. The COL1A1-PDGFB translocation should be analyzed in cases of unclear diagnosis and when it is necessary to identify candidates for tyrosine kinase inhibitors. Imatinib is indicated for the treatment of locally advanced and metastatic dermatofibrosarcoma protuberans.

Congenital atrophic dermatofibrosarcoma protuberans detected by COL1A1-PDGFB rearrangement

Background

Atrophic variant of dermatofibrosarcoma protuberans (DFSP) is a distinct form of DFSP.

Case presentation

Here, we report the case of a 19-year-old woman with a small congenital atrophic plaque on the right precordium. The lesion remained atrophic for more than 10 years. Several years earlier, a portion of the plaque became tuberous and enlarged. Physical examination revealed a 25 × 30 mm erythematous atrophic plaque surrounded by three hard, smooth, and orange-colored nodules of varying sizes on the right precordium, along with visible subcutaneous adipose tissue and cutaneous veins. Biopsy of the nodule and atrophic plaque revealed dense proliferation of spindle-shaped tumor cells from the dermis to the subcutaneous adipose tissue, and positive immunostaining for CD34 and vimentin in addition to negative staining for factor XIIIa and α-smooth muscle actin. Reverse transcription polymerase chain reaction (RT-PCR) of the tumor tissue revealed the presence of a COL1A1-PDGFB fusion gene. Thus, congenital atrophic dermatofibrosarcoma protuberans was diagnosed. No metastasis to the lungs or regional lymph nodes was found on magnetic resonance imaging. Wide local excision and split-thickness skin grafting was performed and neither recurrence nor metastasis has been observed for 5 years and 8 months since the surgery.

Conclusion

This case indicates that a congenital atrophic lesion could represent a quiescent phase of DFSP. Awareness of this rare condition can aid with early diagnosis and thereby improve the prognosis of DFSP.

Dermatoscopic findings of atrophic dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans (DFSP) is an uncommon locally aggressive mesenchymal tumor with a high local recurrence rate. Atrophic DFSP is a rare variant of DFSP characterized by a non-protuberant lesion. We report on a 23-year-old female, who presented with an atrophic, asymptomatic macule on the right side of her back 2 cm in diameter. Dermatoscopic examination revealed homogenous pigment network on a purplish erythematous background. The histopathological finding of the incisional biopsy material was consistent with DFSP. To our knowledge, this is the second case of atrophic DFSP discussing the dermatoscopic features of this relatively rare condition.

Dermatofibrosarcoma protuberans in an adolescent: a case report and review of the literature

Classically, dermatofibrosarcoma protuberans (DFSP) is a disease of adults. The world literature revision shows that several pediatric cases have been reported so far; this might suggest that the number of infants with the condition might be larger than that estimated previously. Here, we report the 183rd case of histologically confirmed DFSP in young age. A 14-year-old white male patient came under our care for a slowly growing, pale brownish lesion on the neck skin. A biopsy specimen showed a DFSP. Subsequently, a wide surgery excision with 3 cm of resection margins including the underlying fascia was performed. To date, the patient has been in follow-up for 6 years without evidence of recurrent disease. The clinical features and treatment of DFSP diagnosed in childhood and adolescence reported in the published literature are reviewed to provide new insights about this rare entity. The aim is to emphasize the importance of biopsy for histologic evaluation in the cases that show a persistent or a large cutaneous plaque or nodule without pathognomonic clinical features that permit a clinical diagnosis. An accurate knowledge of the disease is the prerequisite for a wider recognition and appropriate treatment.

Atrophic dermatofibrosarcoma protuberans

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is an uncommon malignant mesenchymal tumor that arises in the dermis and is characterised by latency in its initial detection. As a rare form, atrophic or morphea-like DFSP has been documented. Atrophic DFSP resemble other benign lesions such as morphea, idiopathic atrophoderma, atrophic scar, anetoderma or lipoatrophy. It behaves like classic DFSP. It commonly favours young to middle aged adults. It has a slow infiltrative growth and a high rate of local recurrence if not completely excised. Metastases are rare and occur after repeated local recurrence. Surgical excision is the best line of treatment. Long term follow up is required to detect recurrence.

MAIN OBSERVATIONS

We report a case of atrophic DFSP in a 52-year-old female patient. Diagnosis was achieved according to clinical, histopathological and immunohistochemical findings. Tumor was surgically excised with safety margin and the patient is still under follow up.

CONCLUSIONS

Atrophic DFSP is a rare variant of DFSP. It is a tumor of low to moderate grade malignancy. Surgical excision is the best line of management. Long term follow up is necessary.

Dermatofibrosarcoma protuberans: clinical, pathological, and genetic (COL1A1-PDGFB ) study with therapeutic implications

AIMS

To analyse the presence of collagen type I alpha 1-platelet-derived growth factor beta (COL1A1-PDGFB) transcripts in 20 cases of dermatofibrosarcoma protuberans (DFSP) and to assess the relationship between COL1A1 breakpoints and clinical and histopathological variables.

METHODS AND RESULTS

Multiplex reverse transcriptase-polymerase chain reaction was carried out using frozen tissue. Our series contained 14 men and six women. Histologically, most cases were of conventional type (n = 9), followed by fibrosarcoma (n = 4), Bednar tumour (n = 2), sclerosing (n = 2), myoid (n = 1) and atrophic (n = 1) DFSP, and giant cell fibroblastoma (n = 1). Immunohistochemistry revealed CD34 expression in 90% of cases. COL1A1-PDGFB fusion transcripts were present in 89% of cases (exons 18, 19, 20, 25, 26, 31, 33/34, 39, 40, 46, 47 and 48 of COL1A1 with exon 2 of PDGFB). There was no recurrence of DFSP in any of the 19 patients treated by Mohs surgery. A partial response was obtained in the two patients treated with imatinib.

CONCLUSIONS

The COL1A1-PDGFB fusion was present in all histological subtypes of DFSP, but not all cases expressed the fusion transcript. No association was observed between different COL1A1 breakpoints and clinicopathological parameters. Imatinib mesylate can be useful in locally advanced tumours and metastases.

Congenital atrophic dermatofibrosarcoma protuberans in a 7-month-old boy treated with Mohs micrographic surgery

Dermatofibrosarcoma protuberans is a rare, malignant, slow-growing, locally invasive tumor of the skin. Although most cases are acquired and diagnosed in adulthood, there have been an increasing number of congenital dermatofibrosarcoma protuberans mimicking benign birthmarks described in the literature. The clinical presentation of this tumor is often one of an indurated exophytic plaque or nodule; however, a rare variant can present as atrophic or sclerotic in nature. We report a case of congenital atrophic dermatofibrosarcoma protuberans of the groin in a 7-month-old boy, successfully treated with Mohs micrographic surgery.

Dermatofibrosarcoma protuberans in childhood and adolescence: report of eight patients

We reviewed all occurrences of dermatofibrosarcoma protuberans in children under 17 years of age who were evaluated at Sainte-Justine Hospital, a tertiary-care pediatric center, between 1980 and 2002. The medical records and histologic features of all were reviewed. Eight patients were identified, three boys and five girls. The interval between apparent onset and diagnosis ranged from 3 months to 14 years. All lesions except one were removed by surgical excision with a margin of 1.5 to 3 cm including underlying fascia or by Mohs technique. Follow-up ranged from 2 to 15 years with median of 5 years. To date all the patients are alive and none has had a recurrence.

Atrophic dermatofibrosarcoma protuberans with diffuse eosinophilic infiltrate

Atrophic dermatofibrosarcoma protuberans (atrophic DFSP) is a variant of dermatofibrosarcoma protuberans (DFSP), and is clinically characterized by depressed lesions. We report a patient with a typical atrophic DFSP lesion with marked eosinophilic infiltration. The patient was a 55-year-old woman with a dark-red, depressed lesion in the epigastric region. Histopathological examination of the lesion showed proliferation of fibroblast-like cells in a storiform pattern in the dermis and subcutaneous tissue. Immunohistochemical staining of tumor cells was positive for CD34. The lesion was histopathologically typical of DFSP, but no elevated lesion was clinically observed. Thus, a diagnosis of atrophic DFSP was made. Moreover, this tumor tissue exhibited marked eosinophilic infiltration. To our knowledge, they are no reports of eosinophilic infiltration in DFSP tissue. Therefore, this seems to be an extremely rare case of DFSP.

Clinical variants of the preprotuberant stage of dermatofibrosarcoma protuberans

BACKGROUND

Some cases of dermatofibrosarcoma protuberans (DFSP) do not protrude above the skin.

OBJECTIVES

To assess the prevalence of these DFSPs and further to describe their presentation and course.

METHODS

One hundred and forty-three patients were retrospectively collected. They were asked to complete a standardized questionnaire indicating the history and appearance of the DFSP from the first skin changes identified to the time of diagnosis.

RESULTS

Eighty-one DFSPs were described as protuberant ab initio, and 62 as initially nonprotuberant (npDFSP). The latter remained at this stage for a mean period of 7.6 years. Twenty-nine per cent of npDFSPs were 'morphoea-like', 19% were 'atrophoderma-like' and 42% were 'angioma-like'. Age at diagnosis was similar for both initial presentations. npDFSPs were most often misdiagnosed by physicians.

CONCLUSIONS

Nearly half the patients first identified their early DFSP-related skin changes as patches. Both this frequency and the long duration at this preprotuberant stage should prompt dermatologists to consider the diagnosis of DFSP earlier, in order to make surgical treatment easier.

Atrophic dermatofibrosarcoma protuberans

A 48-year-old woman presented with a 20-year history of an asymptomatic depressed atrophic plaque on the abdomen. Five years earlier a punch biopsy of the same lesion had been carried out and a diagnosis of dermatofibroma was made. She was reassured and discharged. Further consultation was sought due to extension and thickening of the lesion. Re-examination of the initial and new incisional biopsy specimens, along with histochemical staining for CD34, established the diagnosis of atrophic dermatofibrosarcoma protuberans. A wide local excision was carried out. There has been no recurrence at 9 months of follow up.

Atrophic dermatofibrosarcoma protuberans: an uncommon and misleading variant

A 23-year-old man presented with an atrophic lesion on his left anterior shoulder that had been present for at least 10 years. A previous biopsy had suggested a fibrohistiocytic origin; however, clinically it resembled morphoea or atrophoderma, and the lesion was observed. Fifteen months later, the lesion was noted to have grown slightly. A repeat biopsy showed dermatofibrosarcoma protuberans, with a storiform spindle cell proliferation with positive CD34 staining. The lesion was excised with a 3-cm margin. Awareness of this rare presentation may assist in earlier diagnosis.

Atrophic dermatofibrosarcoma protuberans: case report, review, and proposed molecular mechanisms

We report a case of atrophic dermatofibrosarcoma protuberans, an uncommon clinical variant. We discuss molecular and genetic mechanisms of dermatofibrosarcoma protuberans tumorigenesis, review the literature on atrophic dermatofibrosarcoma protuberans, and pose a molecular mechanism for the atrophic variant's phenotype. We also describe using Mohs micrographic excision with CD34 immunostains on the frozen sections to definitively treat the tumor.

A case of childhood dermatofibrosarcoma protuberans without detected cytogenetic abnormality

Dermatofibrosarcoma protuberans (DFSP) is a rare, infiltrative skin tumour of intermediate malignancy, with a limited potential for metastasis but a high rate of recurrence; specific cytogenetic abnormalities are now known. Childhood DFSP has been considered a rarity in the past, but it is now recognized that many cases of childhood DFSP are diagnosed only in adulthood. Despite advances in the understanding of its pathogenesis as well as the development of valuable immunohistochemical and cytogenetic diagnostic techniques, there often remains a significant delay between the initial presentation and diagnosis of DFSP. We report a case of childhood DFSP in which the diagnosis was reached only after a nodular lesion developed in a plaque that was initially present. Causes for delay between initial presentation and diagnosis in childhood DFSP are discussed. Histology and immunostaining in our patient showed the typical features of DFSP, but the G-banded cytogenetic analysis of short-term tissue culture was negative. However, this technique offers only a detection rate between 50% and 80%. Clinicians should be aware of the limitations of newer diagnostic techniques. Increasing recognition amongst paediatricians and paediatric dermatologists that childhood DFSP is not as rare as once believed will probably lead to the use of newer diagnostic methods at an earlier stage, and so reduce the delay between the onset of symptoms and diagnosis.

Congenital and childhood dermatofibrosarcoma protuberans: a case report and review of the literature

Dermatofibrosarcoma protuberans (DFSP) occurs most commonly on the trunk, affects all races, and often develops between the second and fifth decades of life. It is uncommon in childhood and is sometimes mistaken for a vascular lesion, as it often presents as a blue macule or small nodule. Review of the English literature revealed approximately 152 cases of DFSP developing before 16 years of age and only 19 claimed congenital cases. A case of congenital dermatofibrosarcoma protuberans is presented with a literature review and discussion of congenital and childhood presentations of the tumor.

A pediatric case of dermatofibrosarcoma protuberans: an immunohistochemical study

Dermatofibrosarcoma protuberans (DFSP) is a fibrohistiocytic tumor of intermediate malignancy that usually occurs in early or mid-adult life as a nodular cutaneous mass. DFSP has rarely been reported during childhood or at birth. We report a case of childhood DFSP that illustrates the usefulness of immunohistochemical analysis in the differential diagnosis between DFSP and other fibrohistiocytic proliferations occurring in the skin. A prompt and correct diagnosis is very important in order to ensure appropriate treatment and to prevent local recurrences.

Dermatofibrosarcoma protuberans: an early non-protuberant phase of the tumour

A 40-year-old female patient presented with a flat scar like plaque on the upper chest. The patient's perception of subtle change in the lesion was of paramount importance in the decision to biopsy this lesion of innocuous clinical appearance. Histopathological findings were those of dermatofibrosarcoma protuberans. This case illustrates the early clinical features of the tumour and a recommendation for taking a biopsy of any scar-like plaque where there is no clear history of preceding trauma.

Atrophic and plaquelike dermatofibrosarcoma protuberans

It is clinically important to realize that dermatofibrosarcoma protuberans (DFSP) often begins as a nonprotuberant plaque and occasionally persists as such. Cases of what has been called atrophic DFSP have recently been reported. None of these cases varied either histologically or prognostically from classical nodular DFSP, and all should be considered part of the clinical spectrum of DFSP. However, histologic variants of DFSP can portend a worse prognosis. The fibrosarcomatous variant, which is fascicular and does not immunostain with anti-CD34, is an example. Recently, another fascicular variant that does positively immunostain with anti-CD34 has been described as plaquelike DFSP. We described a case of a DFSP that had histologically banal, slender fascicles of anti-CD34 immunostaining spindle cells in a clinically nonprotuberant plaque despite subsequently developing a nodule with typical storiform histology. The importance of anti-CD34 immunoperoxidase staining in the diagnosis and prognosis of DFSP variants is emphasized.

Malignant fibrous tumors

Dermatofibrosarcoma protuberans (DFSP), atypical fibroxanthoma (AFX), and malignant fibrous histiocytoma (MFH) are rare soft tissue sarcomas of intermediate to high-grade malignancy that the dermatologist must evaluate and treat. DFSP is a fibrohistiocytic tumor of intermediate malignancy characterized by aggressive local growth and propensity to recur after surgical excision. AFX is a superficial malignant tumor that arises on sun-exposed surfaces and is characterized by local aggressive behavior. MFH is the most aggressive of the fibrohistiocytic tumors with a high local recurrence rate and significant metastatic rate usually associated with a poor prognosis. This article reviews the epidemiology, pathogenesis, clinical presentation, histology, management, prognosis, and follow-up of these malignant tumors.

Unusual cutaneous malignancies

The most commonly occurring cutaneous malignancies are basal cell and squamous cell carcinoma. There are, however, other rare malignancies that are encountered and should be included in the differential, in which both the clinical and the histological diagnosis may be difficult. Here, the clinical and histological features, management, and prognostic factors of merkel cell carcinoma, microcystic adnexal carcinoma, leiomyosarcoma, dermatofibrosarcoma protuberans, and angiosarcoma are reviewed.

Dermatofibrosarcoma protuberans

Dermatofibrosarcoma protuberans is a tumor of intermediate malignancy characterized by its aggressive local growth and marked propensity to recur after surgical excision. This article reviews the incidence, clinical presentation, histologic features, immunocytochemical studies, histogenesis, prognosis, management, and follow-up recommendations for this unusual neoplasm.

Soft tissue sarcomas in dermatology

BACKGROUND

Dermatofibrosarcoma protuberans, atypical fibroxanthoma, and cutaneous leiomyosarcoma are uncommon soft tissue sarcomas that tend to have a high recurrence rate when removed with standard excisional surgery, and in some cases have been reported to metastasize. These tumors have been reported in the surgical, medical, and pathology literature. The diagnosis and treatment of these tumors is still evolving. Wide excision and surgical techniques involving meticulous surgical margin control appear to be the most efficacious treatment for these problematic tumors.

OBJECTIVE

The surgical, medical, and pathology literature was extensively reviewed to collate the observations of multiple investigators, and to summarize their findings. Literature from medical journals of multiple subspecialties as well as textbooks were reviewed with particular emphasis on diagnosis, histologic features including immunohistochemistry, and useful surgical techniques that facilitate the removal of these difficult tumors.

RESULTS

Dermatofibrosarcoma protuberans is a soft tissue neoplasm of intermediate malignancy that shows a high recurrence rate when treated with standard excision. Wide surgical excision using a 3-cm margin greatly reduces the risk of recurrence, but is not practical in some cases. Evidence is continuing to accumulate that Mohs micrographic surgery may be the treatment of choice for this tumor. Atypical fibroxanthoma is best thought of as a superficial form of malignant fibrous histiocytoma. It is histologically indistinguishable from certain forms of malignant fibrous histiocytoma and differs primarily in its size and superficial location. These tumors are best removed surgically. For most smaller tumors a 1-cm margin, which is carried down to the subcutaneous tissue, provides adequate treatment. In cases where tissue conservation is important, Mohs micrographic surgery has been shown to be very effective. Cutaneous leiomyosarcoma is a rare superficial soft tissue sarcoma that has a high incidence of recurrence after excision and can metastasize. Because of the small number of patients treated, treatment recommendations are still evolving. Currently, wide local excision is recommended with a 3-5 cm margin and removal of the underlying subcutaneous tissue. Mohs micrographic surgery has been used in a small number of cases with good success.

CONCLUSION

Dermatofibrosarcoma protuberans, atypical fibroxanthoma, and cutaneous leiomyosarcoma are soft tissue sarcomas that have a high rate of recurrence when treated with standard surgical techniques and may occasionally metastasize. When removing these tumors it is very important to take adequate margins. Mohs micrographic surgery is proving to be very useful in treating these difficult neoplasms.

Dermatofibrosarcoma protuberans

BACKGROUND

Dermatofibrosarcoma protuberans (DFSP) is an uncommon malignant tumor of the skin, the diagnosis of which can be difficult not only clinically but also histologically. The tumor has a low metastatic potential, but tends to recur locally if removal is incomplete.

METHODS

We reviewed the clinical and histologic features of 19 cases of DFSP, seen at the Department of Dermatology (14 cases) and Department of Surgery (5 cases) at the Hull Royal Infirmary between 1975 and 1992.

RESULTS

There were only 19 cases of DFSP diagnosed from a population of 500,000 over a period of 17 years. None of the cases were diagnosed clinically prior to histologic diagnosis. The highest incidence was in the 4th decade of age. The most frequent site was on the head and neck. None of the lesions metastasized but there were a total of eight incidents of local recurrence in five patients. Histologically all the cases showed presence of storiform-pattern spindle-shaped cells and new collagen formation.

CONCLUSIONS

Dermatofibrosarcoma protuberans is a soft tissue tumor that is often not recognized clinically due to its rarity and variable appearance. Local recurrence is frequent. A wide surgical excision is the treatment of choice.

Atrophic dermatofibroma and dermatofibrosarcoma protuberans

Dermatofibroma and dermatofibrosarcoma protuberans usually are seen as firm nodules in the skin. We have observed several patients, all female, with an atrophic or depressed lesion on the chest or back. When biopsy was done, the biopsy punch was often noted to sink into the lesion. In each case the biopsy specimen showed a cellular dermatofibroma or dermatofibrosarcoma protuberans. The correct diagnosis was rarely suspected clinically. This uncommon clinical presentation may be related to the marked cellularity of the fibrous tumors in this series.

Colonization of nonmelanocytic cutaneous lesions by dendritic melanocytic cells: a simulant of acral-lentiginous (palmar-plantar-subungual-mucosal) melanoma

Four cases of colonization of nonmelanocytic lesions by dendritic melanocytic cells are reported, one in a verruca vulgaris of the lip, one in a squamous cell carcinoma in situ of mucous membrane overlying a tonsil, one in a lesion of lichen simplex chronicus with a nevocellular nevus of the external ear, and one in a dermatofibrosarcoma protuberans (Bednar tumor). This is an important biological process of melanocytes that must not be confused with the acral-lentiginous (palmar-plantar-subungual-mucosal (P-S-M) melanoma. It is probably much more common than the paucity of published reports would indicate.