title: [Cellular fibrous histiocytoma: a clinicopathologic analysis of 27 cases].
abstract: OBJECTIVE
  To study the clinicopathologic characteristics of cellular fibrous histiocytoma (CFH) with emphasis on diagnosis and differential diagnosis.
  
  
  METHODS
  Clinical 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.
  
  
  RESULTS
  The 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.
  
  
  CONCLUSIONS
  CFH 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.
authors.affiliation: Department of Pathology, Fudan University, Shanghai, China.
authors.forename: Yan-ping
authors.initials: YP
authors.lastname: Zhong
authors.forename: Jian
authors.initials: J
authors.lastname: Wang
mesh_terms: D000199:Actins / Q000378:metabolism; D000293:Adolescent; D000328:Adult; D018952:Antigens, CD34 / Q000378:metabolism; D018223:Dermatofibrosarcoma / Q000378:metabolism / Q000473:pathology; D003937:Diagnosis, Differential; D005121:Extremities; D005260:Female; D005500:Follow-Up Studies; D006258:Head and Neck Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D018219:Histiocytoma, Benign Fibrous / Q000378:metabolism / Q000473:pathology* / Q000556:secondary / Q000601:surgery; D006801:Humans; D008175:Lung Neoplasms / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D012189:Retrospective Studies; D012878:Skin Neoplasms / Q000378:metabolism / Q000473:pathology* / Q000601:surgery; D055815:Young Adult
chemical_list: C541116:ACTA2 protein, human; D000199:Actins; D018952:Antigens, CD34