Objective: To investigate the clinicopathological and cytogenetic features of cryptic COL1A1-PDGFB fusion dermatofibrosarcoma protuberans (CC-DFSP). Methods: Three cases of CC-DFSP diagnosed in West China Hospital, Sichuan University, Chengdu, China from January 2021 to September 2021 were studied. Immunohistochemistry for CD34 and other markers, fluorescence in situ hybridization (FISH) for PDGFB, COL1A1-PDGFB and COL1A1, next-generation sequencing (NGS), reverse-transcriptase polymerase chain reaction (RT-PCR) and Sanger sequencing were performed. Results: There were three cases of CC-DFSP, including two females and one male. The patients were 29, 44 and 32 years old, respectively. The sites were abdominal wall, caruncle and scapula. Microscopically, they were poorly circumscribed. The spindle cells of the tumors infiltrated into the whole dermis or subcutaneous tissues, typically arranging in a storiform pattern. Immunohistochemically, the neoplastic cells exhibited diffuse CD34 expression, but were negative for S-100, SMA, and Myogenin. Loss of H3K27me3 was not observed in the tumor cells. The Ki-67 index was 10%-15%. The 3 cases were all negative for PDGFB rearrangement and COL1A1-PDGFB fusion, whereas showing unbalanced rearrangement for COL1A1. Case 1 showed a COL1A1 (exon 31)-PDGFB (exon 2) fusion using NGS, which was further validated through RT-PCR and Sanger sequencing. All patients underwent extended surgical resection. Except for case 3 with recurrence 2 years after surgical resection, the other 2 cases showed no recurrence or metastasis during the follow-up. Conclusions: FISH has shown its validity for detecting PDGFB rearrangement and COL1A1-PDGFB fusion and widely applied in clinical detection. However, for cases with negative routine FISH screening that were highly suspicious for DFSPs, supplementary NGS or at least COL1A1 break-apart FISH screening could be helpful to identify cryptic COL1A1-PDGFB fusions or other variant fusions.
Female ; Humans ; Male ; Collagen Type I, alpha 1 Chain ; Dermatofibrosarcoma/pathology* ; In Situ Hybridization, Fluorescence ; Oncogene Proteins, Fusion/genetics* ; Proto-Oncogene Proteins c-sis/genetics* ; Skin Neoplasms/pathology* ; Adult

PURPOSE: Dermatofibrosarcoma protuberans (DFSP) carries a translocation resulting in the collagen type I alpha 1 (COL1A1)-platelet-derived growth factor beta (PDGFB) fusion gene, which is responsible for PDGFB activation. The purpose of this study is to evaluate the clinicopathological, genetic, and therapeutic features of DFSP in Korean patients. MATERIALS AND METHODS: Clinicopathological features of 37 patients with DFSP were reviewed. Multiplex reverse transcriptase-polymerase chain reaction (PCR) was carried out in 16 patients using formalin-fixed, paraffin-embedded tissues and specific primers for COL1A1 and PDGFB. RESULTS: The mean age of 37 patients was 37.4 years old. The most common tumor location was the trunk. All patients were treated primarily with surgery: 34 (91.7%) cases with Mohs micrographic surgery (MMS) and 3 (8.3%) cases with wide local excision. The median follow-up time was 33.7 months. Two patients, one in each treatment group, demonstrated local recurrence during the follow-up period. The COL1A1-PDGFB fusion gene was expressed in 14 (87.5%) cases, demonstrated by reverse transcriptase PCR analysis. No association was found among the different COL1A1-PDGFB fusion transcripts, the various histological subtypes and clinical features. CONCLUSION: Our results support the effectiveness of MMS in treating DFSP. The COL1A1-PDGFB fusion transcript was observed in 87.5% of patients. Therefore, COL1A1-PDGFB is a useful and accurate tool in diagnosing DFSP in Koreans.
Adolescent ; Adult ; Asian Continental Ancestry Group/*genetics ; Collagen Type I/*genetics ; DNA Primers ; Dermatofibrosarcoma/ethnology/*genetics/*pathology/surgery ; Female ; Humans ; Male ; Middle Aged ; Mohs Surgery ; Multiplex Polymerase Chain Reaction ; Neoplasm Recurrence, Local ; Oncogene Proteins, Fusion/*genetics ; Proto-Oncogene Proteins c-sis/*genetics ; Republic of Korea ; Reverse Transcriptase Polymerase Chain Reaction ; Skin Neoplasms/ethnology/*genetics/*pathology/surgery ; Treatment Outcome

PURPOSE: Dermatofibrosarcoma protuberans (DFSP) carries a translocation resulting in the collagen type I alpha 1 (COL1A1)-platelet-derived growth factor beta (PDGFB) fusion gene, which is responsible for PDGFB activation. The purpose of this study is to evaluate the clinicopathological, genetic, and therapeutic features of DFSP in Korean patients. MATERIALS AND METHODS: Clinicopathological features of 37 patients with DFSP were reviewed. Multiplex reverse transcriptase-polymerase chain reaction (PCR) was carried out in 16 patients using formalin-fixed, paraffin-embedded tissues and specific primers for COL1A1 and PDGFB. RESULTS: The mean age of 37 patients was 37.4 years old. The most common tumor location was the trunk. All patients were treated primarily with surgery: 34 (91.7%) cases with Mohs micrographic surgery (MMS) and 3 (8.3%) cases with wide local excision. The median follow-up time was 33.7 months. Two patients, one in each treatment group, demonstrated local recurrence during the follow-up period. The COL1A1-PDGFB fusion gene was expressed in 14 (87.5%) cases, demonstrated by reverse transcriptase PCR analysis. No association was found among the different COL1A1-PDGFB fusion transcripts, the various histological subtypes and clinical features. CONCLUSION: Our results support the effectiveness of MMS in treating DFSP. The COL1A1-PDGFB fusion transcript was observed in 87.5% of patients. Therefore, COL1A1-PDGFB is a useful and accurate tool in diagnosing DFSP in Koreans.
Adolescent ; Adult ; Asian Continental Ancestry Group/*genetics ; Collagen Type I/*genetics ; DNA Primers ; Dermatofibrosarcoma/ethnology/*genetics/*pathology/surgery ; Female ; Humans ; Male ; Middle Aged ; Mohs Surgery ; Multiplex Polymerase Chain Reaction ; Neoplasm Recurrence, Local ; Oncogene Proteins, Fusion/*genetics ; Proto-Oncogene Proteins c-sis/*genetics ; Republic of Korea ; Reverse Transcriptase Polymerase Chain Reaction ; Skin Neoplasms/ethnology/*genetics/*pathology/surgery ; Treatment Outcome

Classification ; methods ; Dermatofibrosarcoma ; classification ; pathology ; Gastrointestinal Stromal Tumors ; immunology ; pathology ; Hemangioendothelioma ; classification ; metabolism ; pathology ; Humans ; Neoplasms, Connective and Soft Tissue ; classification ; metabolism ; pathology ; Neurilemmoma ; pathology ; Rhabdomyosarcoma ; metabolism ; pathology ; Sclerosis ; World Health Organization

OBJECTIVETo investigate the clinical pathological features, diagnosis and differential diagnosis of pigmented dermatofibrosarcoma protuberance (PDFSP).

METHODSThe clinical history, histopathological features, immunohistochemical characteristics, treatment and prognosis were analyzed in seven cases of PDFSP. Fluorescence in situ hybridization (FISH) was used to detect the expression of COL1A1/PDGFB fusion gene, and related literature was reviewed.

RESULTSThe median age of the seven patients (4 females, 3 males) was 47 years with the tumors involving mostly the trunk (four cases). Histologically, PDFSP showed a cellular lesion composed of spindle cells arranged in short fascicles that form a distinct storiform pattern, and the pigmented bipolar or multipolar dendritic cells were present with tentacle like processes emanating from a nucleus containing zone. One case showed fibrosarcomatous change. The pigment was tinctorially similar to melanin. The spindle cells were positive for CD34 and vimentin, but negative for HMB45, Melan A, S-100, desmin, CD68 or α-SMA. HMB45, Melan A, S-100 and vimentin were expressed in the melanin containing cells in 4, 4, 5 and 7 cases, respectively. The labeling index of Ki-67 was 1%-8%. Among the 4 cases successfully examined by FISH, 3 showed t(17;22)(q21;q13) which suggested COL1A1/PDGFB fusion gene. Three patients were treated by wide local excision and four were treated by simple surgical excision. Two patients developed recurrences during the follow-up period of 12 to 123 months. Of those treated by wide local excision, none developed recurrence. No patient died in the follow-up period.

CONCLUSIONSPDFSP is a rare pigmented variant of DFSP and an intermediate grade malignant tumor. The orgin of the tumor cells is still controversial. Surgical pathologists and dermatopathologists need to be aware of the prototypical histological appearance of PDFSP as there is a risk of misdiagonsing it as either pigmented tumors associated with neurocutaneous syndromes or a highly malignant melanocytic neoplasm.

Adult ; Aged ; Antigens, CD34 ; metabolism ; Child, Preschool ; Dermatofibrosarcoma ; diagnosis ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Humans ; Immunohistochemistry ; In Situ Hybridization, Fluorescence ; MART-1 Antigen ; metabolism ; Male ; Melanoma ; metabolism ; pathology ; Melanoma-Specific Antigens ; metabolism ; Middle Aged ; Neoplasm Recurrence, Local ; Neurilemmoma ; metabolism ; pathology ; Neurofibroma ; metabolism ; pathology ; Oncogene Proteins, Fusion ; metabolism ; Prognosis ; Retrospective Studies ; S100 Proteins ; metabolism ; Skin Neoplasms ; diagnosis ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

OBJECTIVETo investigate the clinical pathological features of fibrosarcomatous dermatofibrosarcoma protuberans (FS-DFSP).

METHODSThe clinical history, histopathological features and immunohistochemical characteristics were analyzed in twelve cases of FS-DFSP from January 1997 to February 2011, and related literature were reviewed.

RESULTSAge of the patients (2 females, 10 males) at diagnosis ranged from 41 to 70 years (mean 53 years). Among the 12 cases of FS-DFSP, 9 cases aroused in recurrent ordinary DFSP. Histologically, FS areas in FS-DFSP were characterized by a fascicular and highly cellular histology, frequently showing a characteristic herringbone pattern. FS-DFSP showed diminishment of CD34 staining in FS areas. The labeling index of Ki-67 was much higher in the FS areas (10%-40%) than that in the conventional DFSP areas (2%-5%). All the patients were treated by operation with local excision or wide excision. Postoperative radiotherapy and chemotherapy was administered in two cases respectively. Follow-up information in 9 of 12 patients (9 to 86 months) revealed local recurrence in 6 patients. Distant metastases were seen in two patients. One patient was died in the follow up period.

CONCLUSIONSFS-DFSP is a rare and unique subtype of DFSP and is associated with significant elevated risk of both local and distance metastasis, usually followed by poor outcome. Compared to ordinary DFSP as a borderline neoplasm, FS-DFSP should be considered as a malignant tumor.

Adult ; Aged ; Antigens, CD34 ; metabolism ; Chemotherapy, Adjuvant ; Dermatofibrosarcoma ; metabolism ; pathology ; therapy ; Diagnosis, Differential ; Female ; Fibroma ; pathology ; Fibrosarcoma ; metabolism ; pathology ; therapy ; Follow-Up Studies ; Histiocytoma, Benign Fibrous ; metabolism ; pathology ; Histiocytoma, Malignant Fibrous ; pathology ; Humans ; Ki-67 Antigen ; metabolism ; Lung Neoplasms ; secondary ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Radiotherapy, Adjuvant ; Retrospective Studies ; Skin Neoplasms ; metabolism ; pathology ; therapy

Cell Differentiation ; Child ; Dermatofibrosarcoma ; metabolism ; pathology ; Diagnosis, Differential ; Humans ; Immunohistochemistry ; Infant ; Lipoblastoma ; metabolism ; pathology ; Liver Neoplasms ; metabolism ; pathology ; Mesenchymoma ; metabolism ; pathology ; Neoplasms, Germ Cell and Embryonal ; metabolism ; pathology ; Sarcoma ; metabolism ; pathology ; Skin Neoplasms ; metabolism ; pathology ; Soft Tissue Neoplasms ; metabolism ; pathology

OBJECTIVETo study the clinicopathologic characteristics of cellular fibrous histiocytoma (CFH) with emphasis on diagnosis and differential diagnosis.

METHODSClinical and pathologic features were reviewed in 27 cases of CFH (encountered during the period from 2008 to 2012) along with outcome analysis. Immunophenotyping was performed with EnVision method.

RESULTSThe patients included 13 males and 14 females. The age at presentation ranged from 15 to 61 years (mean, 34 years; median, 32 years). The tumor occurred in the extremities (n = 14), head and neck (n = 7), and trunk (n = 6). Histologically, the tumors were located in the dermis. Some cases showed wedge like extension into the subcutaneous adipose tissue. On high power, they consisted of dense fibroblasts and myofibroblasts. Other cell components such as psammoma-like histiocytes, hemosiderin-containing macrophages or touton-type giant cells were rare. The spindled tumor cells were arranged mostly in intersecting fascicles. Focal storiform architecture was not uncommon. In addition, a few cases showed prominent hemangiopericytoma-like pattern. There was no prominent cellular atypia but increased mitotic figures were not difficult to find. Two cases exhibited necrosis. By immunohistochemistry, the tumor cells showed variable expression of alpha smooth muscle actin. CD34 positive cells were present in some cases, but were distributed mostly in the periphery or bottom of the lesions. They were all negative for desmin, h-caldesmon, S-100 protein and cytokeratin. Follow-up in 19 cases revealed local recurrences in 5 cases and bilateral pulmonary metastases in 1 case after repeated recurrences.

CONCLUSIONSCFH is a cellular form of benign fibrous histiocytoma which has a risk for local recurrence after incomplete excision. Distant metastasis can occur in rare examples. However, there were no morphological parameters predicting the risk of recurrence or metastasis. Increased awareness of the clinocopathological features and immunophenotypes of CFH is helpful in avoiding misdiagnosing the disease as malignant tumors, especially dermatofibrosarcoma protuberans.

Actins ; metabolism ; Adolescent ; Adult ; Antigens, CD34 ; metabolism ; Dermatofibrosarcoma ; metabolism ; pathology ; Diagnosis, Differential ; Extremities ; Female ; Follow-Up Studies ; Head and Neck Neoplasms ; metabolism ; pathology ; surgery ; Histiocytoma, Benign Fibrous ; metabolism ; pathology ; secondary ; surgery ; Humans ; Lung Neoplasms ; secondary ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Retrospective Studies ; Skin Neoplasms ; metabolism ; pathology ; surgery ; Young Adult

Actins ; metabolism ; Dermatofibrosarcoma ; classification ; pathology ; Desmin ; metabolism ; Head and Neck Neoplasms ; metabolism ; pathology ; Histiocytoma, Benign Fibrous ; classification ; metabolism ; pathology ; Histiocytoma, Malignant Fibrous ; classification ; metabolism ; pathology ; Humans ; Oncogene Proteins, Fusion ; metabolism ; Skin Neoplasms ; metabolism ; pathology ; Vimentin ; metabolism ; Xanthomatosis ; pathology

Adult ; Antigens, CD ; metabolism ; Antigens, CD34 ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Dermatofibrosarcoma ; metabolism ; pathology ; surgery ; Diagnosis, Differential ; Female ; Fibroma ; metabolism ; pathology ; Humans ; Lipoma ; pathology ; Neurofibroma ; metabolism ; pathology ; Receptors, Cell Surface ; metabolism ; Skin Neoplasms ; metabolism ; pathology ; surgery