Atrophic Dermatofibrosarcoma Can be Tough Call

CHICAGO — Atrophic dermatofibrosarcoma protuberans is an underrecognized variant that must be treated with wide local excision, Dr. Shari Clarke said at the annual meeting of the American Society for Dermatologic Surgery.

Although both wide local excision and Mohs micrographic surgery are considered treatments of choice, the latter quickly is becoming the favored method because of its lower rate of recurrence, she said.

In presenting three cases of the atrophic variant of dermatofibrosarcoma protuberans (DFSP), she explained that these lesions are slow-growing, locally aggressive fibrohistiocytic tumors that rarely metastasize but have a marked tendency toward local recurrence.

"Clinically, DFSP presents as indurated violaceous plaques which later develop nodules, and they're most commonly located on the trunk," explained Dr. Clarke of the department of dermatology at the Milton S. Hershey Medical Center, Pennsylvania State University, Hershey.

Histologically, DFSPs are characterized by monomorphous spindle cells in a storiform pattern that infiltrate between adipocytes. Later, the tumor can involve the upper dermis, deeper subcutaneous fat, or striated muscle, which correlates with the development of nodules and, as "we've demonstrated in our cases, the CD34 staining is very useful in distinguishing DFSPs from other fibrohistiocytic tumors," Dr. Clarke explained.

A total of five distinct early clinical variants of DFSP have been described in the literature, including confluent nodules forming sclerotic plaques, keloidlike sclerotic plaques, tumor, angiomalike, and atrophic DFSP. As exemplified in three cases described by Dr. Clarke, atrophic DFSP may or may not develop nodules in the later stages. In the first two cases, wide excision was used because the procedures were performed by a plastic surgeon.

The third case, involving the crural fold, was performed by a Mohs surgeon.

The first patient, a 43-year-old woman with a 13-year history of asymptomatic nodules that began as an atrophic plaque on the back of her neck, was clinically diagnosed as having multiple neurofibromas. She presented for a second opinion as the nodules continued to enlarge.

A punch biopsy showed monomorphous spindle cells in a fibrous stroma infiltrating the septa between the adipose. CD34 stains were positive and she was given a diagnosis of DFSP, but since her original clinical exam showed atrophic plaque, the diagnosis was changed to atrophic DFSP, Dr. Clarke explained.

A wide excision with 2-cm margins was performed, producing a gross examination specimen measuring 20 by 15 cm. Intraoperative frozen sections with CD34 showed clear 2-cm margins and the wound was reconstructed with a transverse rectus abdominal muscle cutaneous flap utilizing the inferior epigastric artery and vein for blood supply.

The second patient was a 14-year-old girl who presented with a 7-year history of an enlarging, asymptomatic plaque on her right thigh. She was clinically diagnosed as having a keloid and treated without improvement. Surveillance was stopped for a number of years because the patient thought it was "just a scar," Dr. Clarke said, but the nodules continued to enlarge.

On examination, there was an atrophic plaque with scattered nodules that was found on biopsy to be a DFSP.

As with the first patient, the diagnosis was changed to atrophic DFSP.

"She had an excision with 2-cm margins, and the excised specimen was about 30 by 15 cm. Resection was performed down to the quadriceps complex with the 2-cm margins and intraoperative frozen sections showed clear margins," Dr. Clarke said. Reconstruction consisted of a split thickness skin graft from the uninvolved leg.

The third patient was a 40-year-old woman with a 4-by-2.5 cm violaceous atrophic plaque of the right crural fold, said Dr. Clarke, explaining that the patient initially was biopsied and misdiagnosed as having a dermatofibroma.

A repeat biopsy and tumor appearance confirmed atrophic DFSP, which was cleared in two stages using Mohs surgery. The final defect measured 11 by 6 cm. The reconstruction used an advancement flap. Histology showed spindle cells, and a CD34 stain was grossly positive. There has been no evidence of recurrence in the intervening 8 years, said Dr. Clarke, who had no relevant conflicts to disclose.

"Atrophic DFSP, otherwise known as DFSP nonprotuberans or morpheaform DFSP, has been reported infrequently in the dermatologic literature, and like typical DFSP, the atrophic variant has an insidious and aggressive local growth pattern, a similar age of onset, and predominant truncal location," she said, noting that there appears to be a slight female predominance.

Although the atrophic variety is clinically distinct, the treatment and histology are the same as they are for typical DFSP. Adjuvant treatment with imatinib looks promising for very difficult cases.

"Exciting advances in the molecular genetics behind DFSPs have recently been elucidated and have important implications for treatment," she explained, adding that 90% of DFSPs overexpress platelet-derived growth factor β.

"This is important because imatinib mesylate [Gleevec] currently approved for treating chronic myeloid leukemia, acts as a selective tyrosine kinase inhibitor of the platelet-derived growth factor receptor β and has been used successfully in isolated case reports for the presurgical treatment of locally advanced DFSPs and inoperable recurrent or metastatic disease," she said.

Dr. Clarke suggested using 400 mg of imatinib mesylate, the dose used for gastrointestinal stromal tumors, either daily or twice daily. "The side effects are typically mild, although severe edema and liver toxicity have been reported in the elderly," she said.

A patient with DFSPis shown before undergoing wide local excision (left) and 3-months post excision (right). Photos courtesy Rogerio Neves, M.D., Ph.D.

CHICAGO — Atrophic dermatofibrosarcoma protuberans is an underrecognized variant that must be treated with wide local excision, Dr. Shari Clarke said at the annual meeting of the American Society for Dermatologic Surgery.

Although both wide local excision and Mohs micrographic surgery are considered treatments of choice, the latter quickly is becoming the favored method because of its lower rate of recurrence, she said.

In presenting three cases of the atrophic variant of dermatofibrosarcoma protuberans (DFSP), she explained that these lesions are slow-growing, locally aggressive fibrohistiocytic tumors that rarely metastasize but have a marked tendency toward local recurrence.

"Clinically, DFSP presents as indurated violaceous plaques which later develop nodules, and they're most commonly located on the trunk," explained Dr. Clarke of the department of dermatology at the Milton S. Hershey Medical Center, Pennsylvania State University, Hershey.

Histologically, DFSPs are characterized by monomorphous spindle cells in a storiform pattern that infiltrate between adipocytes. Later, the tumor can involve the upper dermis, deeper subcutaneous fat, or striated muscle, which correlates with the development of nodules and, as "we've demonstrated in our cases, the CD34 staining is very useful in distinguishing DFSPs from other fibrohistiocytic tumors," Dr. Clarke explained.

A total of five distinct early clinical variants of DFSP have been described in the literature, including confluent nodules forming sclerotic plaques, keloidlike sclerotic plaques, tumor, angiomalike, and atrophic DFSP. As exemplified in three cases described by Dr. Clarke, atrophic DFSP may or may not develop nodules in the later stages. In the first two cases, wide excision was used because the procedures were performed by a plastic surgeon.

The third case, involving the crural fold, was performed by a Mohs surgeon.

The first patient, a 43-year-old woman with a 13-year history of asymptomatic nodules that began as an atrophic plaque on the back of her neck, was clinically diagnosed as having multiple neurofibromas. She presented for a second opinion as the nodules continued to enlarge.

A punch biopsy showed monomorphous spindle cells in a fibrous stroma infiltrating the septa between the adipose. CD34 stains were positive and she was given a diagnosis of DFSP, but since her original clinical exam showed atrophic plaque, the diagnosis was changed to atrophic DFSP, Dr. Clarke explained.

A wide excision with 2-cm margins was performed, producing a gross examination specimen measuring 20 by 15 cm. Intraoperative frozen sections with CD34 showed clear 2-cm margins and the wound was reconstructed with a transverse rectus abdominal muscle cutaneous flap utilizing the inferior epigastric artery and vein for blood supply.

The second patient was a 14-year-old girl who presented with a 7-year history of an enlarging, asymptomatic plaque on her right thigh. She was clinically diagnosed as having a keloid and treated without improvement. Surveillance was stopped for a number of years because the patient thought it was "just a scar," Dr. Clarke said, but the nodules continued to enlarge.

On examination, there was an atrophic plaque with scattered nodules that was found on biopsy to be a DFSP.

As with the first patient, the diagnosis was changed to atrophic DFSP.

"She had an excision with 2-cm margins, and the excised specimen was about 30 by 15 cm. Resection was performed down to the quadriceps complex with the 2-cm margins and intraoperative frozen sections showed clear margins," Dr. Clarke said. Reconstruction consisted of a split thickness skin graft from the uninvolved leg.

The third patient was a 40-year-old woman with a 4-by-2.5 cm violaceous atrophic plaque of the right crural fold, said Dr. Clarke, explaining that the patient initially was biopsied and misdiagnosed as having a dermatofibroma.

A repeat biopsy and tumor appearance confirmed atrophic DFSP, which was cleared in two stages using Mohs surgery. The final defect measured 11 by 6 cm. The reconstruction used an advancement flap. Histology showed spindle cells, and a CD34 stain was grossly positive. There has been no evidence of recurrence in the intervening 8 years, said Dr. Clarke, who had no relevant conflicts to disclose.

"Atrophic DFSP, otherwise known as DFSP nonprotuberans or morpheaform DFSP, has been reported infrequently in the dermatologic literature, and like typical DFSP, the atrophic variant has an insidious and aggressive local growth pattern, a similar age of onset, and predominant truncal location," she said, noting that there appears to be a slight female predominance.

Although the atrophic variety is clinically distinct, the treatment and histology are the same as they are for typical DFSP. Adjuvant treatment with imatinib looks promising for very difficult cases.

"Exciting advances in the molecular genetics behind DFSPs have recently been elucidated and have important implications for treatment," she explained, adding that 90% of DFSPs overexpress platelet-derived growth factor β.

"This is important because imatinib mesylate [Gleevec] currently approved for treating chronic myeloid leukemia, acts as a selective tyrosine kinase inhibitor of the platelet-derived growth factor receptor β and has been used successfully in isolated case reports for the presurgical treatment of locally advanced DFSPs and inoperable recurrent or metastatic disease," she said.

Dr. Clarke suggested using 400 mg of imatinib mesylate, the dose used for gastrointestinal stromal tumors, either daily or twice daily. "The side effects are typically mild, although severe edema and liver toxicity have been reported in the elderly," she said.

A patient with DFSPis shown before undergoing wide local excision (left) and 3-months post excision (right). Photos courtesy Rogerio Neves, M.D., Ph.D.

CHICAGO — Atrophic dermatofibrosarcoma protuberans is an underrecognized variant that must be treated with wide local excision, Dr. Shari Clarke said at the annual meeting of the American Society for Dermatologic Surgery.

Although both wide local excision and Mohs micrographic surgery are considered treatments of choice, the latter quickly is becoming the favored method because of its lower rate of recurrence, she said.

In presenting three cases of the atrophic variant of dermatofibrosarcoma protuberans (DFSP), she explained that these lesions are slow-growing, locally aggressive fibrohistiocytic tumors that rarely metastasize but have a marked tendency toward local recurrence.

"Clinically, DFSP presents as indurated violaceous plaques which later develop nodules, and they're most commonly located on the trunk," explained Dr. Clarke of the department of dermatology at the Milton S. Hershey Medical Center, Pennsylvania State University, Hershey.

Histologically, DFSPs are characterized by monomorphous spindle cells in a storiform pattern that infiltrate between adipocytes. Later, the tumor can involve the upper dermis, deeper subcutaneous fat, or striated muscle, which correlates with the development of nodules and, as "we've demonstrated in our cases, the CD34 staining is very useful in distinguishing DFSPs from other fibrohistiocytic tumors," Dr. Clarke explained.

A total of five distinct early clinical variants of DFSP have been described in the literature, including confluent nodules forming sclerotic plaques, keloidlike sclerotic plaques, tumor, angiomalike, and atrophic DFSP. As exemplified in three cases described by Dr. Clarke, atrophic DFSP may or may not develop nodules in the later stages. In the first two cases, wide excision was used because the procedures were performed by a plastic surgeon.

The third case, involving the crural fold, was performed by a Mohs surgeon.

The first patient, a 43-year-old woman with a 13-year history of asymptomatic nodules that began as an atrophic plaque on the back of her neck, was clinically diagnosed as having multiple neurofibromas. She presented for a second opinion as the nodules continued to enlarge.

A punch biopsy showed monomorphous spindle cells in a fibrous stroma infiltrating the septa between the adipose. CD34 stains were positive and she was given a diagnosis of DFSP, but since her original clinical exam showed atrophic plaque, the diagnosis was changed to atrophic DFSP, Dr. Clarke explained.

A wide excision with 2-cm margins was performed, producing a gross examination specimen measuring 20 by 15 cm. Intraoperative frozen sections with CD34 showed clear 2-cm margins and the wound was reconstructed with a transverse rectus abdominal muscle cutaneous flap utilizing the inferior epigastric artery and vein for blood supply.

The second patient was a 14-year-old girl who presented with a 7-year history of an enlarging, asymptomatic plaque on her right thigh. She was clinically diagnosed as having a keloid and treated without improvement. Surveillance was stopped for a number of years because the patient thought it was "just a scar," Dr. Clarke said, but the nodules continued to enlarge.

On examination, there was an atrophic plaque with scattered nodules that was found on biopsy to be a DFSP.

As with the first patient, the diagnosis was changed to atrophic DFSP.

"She had an excision with 2-cm margins, and the excised specimen was about 30 by 15 cm. Resection was performed down to the quadriceps complex with the 2-cm margins and intraoperative frozen sections showed clear margins," Dr. Clarke said. Reconstruction consisted of a split thickness skin graft from the uninvolved leg.

The third patient was a 40-year-old woman with a 4-by-2.5 cm violaceous atrophic plaque of the right crural fold, said Dr. Clarke, explaining that the patient initially was biopsied and misdiagnosed as having a dermatofibroma.

A repeat biopsy and tumor appearance confirmed atrophic DFSP, which was cleared in two stages using Mohs surgery. The final defect measured 11 by 6 cm. The reconstruction used an advancement flap. Histology showed spindle cells, and a CD34 stain was grossly positive. There has been no evidence of recurrence in the intervening 8 years, said Dr. Clarke, who had no relevant conflicts to disclose.

"Atrophic DFSP, otherwise known as DFSP nonprotuberans or morpheaform DFSP, has been reported infrequently in the dermatologic literature, and like typical DFSP, the atrophic variant has an insidious and aggressive local growth pattern, a similar age of onset, and predominant truncal location," she said, noting that there appears to be a slight female predominance.

Although the atrophic variety is clinically distinct, the treatment and histology are the same as they are for typical DFSP. Adjuvant treatment with imatinib looks promising for very difficult cases.

"Exciting advances in the molecular genetics behind DFSPs have recently been elucidated and have important implications for treatment," she explained, adding that 90% of DFSPs overexpress platelet-derived growth factor β.

"This is important because imatinib mesylate [Gleevec] currently approved for treating chronic myeloid leukemia, acts as a selective tyrosine kinase inhibitor of the platelet-derived growth factor receptor β and has been used successfully in isolated case reports for the presurgical treatment of locally advanced DFSPs and inoperable recurrent or metastatic disease," she said.

Dr. Clarke suggested using 400 mg of imatinib mesylate, the dose used for gastrointestinal stromal tumors, either daily or twice daily. "The side effects are typically mild, although severe edema and liver toxicity have been reported in the elderly," she said.

A patient with DFSPis shown before undergoing wide local excision (left) and 3-months post excision (right). Photos courtesy Rogerio Neves, M.D., Ph.D.