OBJECTIVETo study the clinicopathologic features, immunophenotype, molecular genetics and differential diagnosis of solid variant of angiomatoid fibrous histocytoma.

METHODSThe clinicopathologic features of 3 cases of solid variant of angiomatoid fibrous histocytoma were analyzed and the literature was reviewed.

RESULTSThere were a total of 2 males and 1 female. The age of patients ranged from 9 to 12 years. The patients presented with a painless mass located in left forearm, left knee or back. The lesions were treated by complete surgical resection. On gross examination, the tumors varied from 1.6 cm to 4.5 cm in greatest dimension. They were well-circumscribed and had pale yellow to grayish-red solid cut surface. Histologically, the tumor was composed of histocytoid cells arranged in sheet-like pattern. A fibrous pseudocapsule surrounded by lymphocytes and plasma cells was identified. Immunohistochemical study showed that the tumor cells in all cases were positive for vimentin and CD68. They were negative for S100 protein, cytokeratin, CD34, CD31, smooth muscle actin, CD35, CD21 and CD30. Two cases also expressed CD99 and one of them was positive for desmin and epithelial membrane antigen. Fluorescence in-situ hybridization was positive for EWSR1 gene.

CONCLUSIONSSolid type represents a variant of angiomatoid fibrous histocytoma and is considered as tumor of borderline malignant potential. Definitive diagnosis requires thorough histologic examination and clinical correlation. Immunohistochemistry and EWSR1 gene study are helpful in further delineation and differential diagnosis. Complete resection or wide local excision with post-operative follow up is the main modality of treatment.

Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Back ; Calmodulin-Binding Proteins ; genetics ; Child ; Dendritic Cell Sarcoma, Follicular ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Forearm ; Histiocytoma, Malignant Fibrous ; genetics ; metabolism ; pathology ; surgery ; Humans ; Knee ; Male ; Neoplasms, Muscle Tissue ; pathology ; Neurilemmoma ; metabolism ; pathology ; RNA-Binding Protein EWS ; RNA-Binding Proteins ; genetics ; Soft Tissue Neoplasms ; genetics ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

Actins ; metabolism ; Angiomyoma ; metabolism ; pathology ; Antigens, CD34 ; metabolism ; Diagnosis, Differential ; Female ; Forearm ; Hemangioma ; metabolism ; pathology ; surgery ; Histiocytoma, Benign Fibrous ; metabolism ; pathology ; Humans ; Middle Aged ; Platelet Endothelial Cell Adhesion Molecule-1 ; metabolism ; Skin Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

OBJECTIVETo study the clinicopathologic characteristics of atypical fibrous histiocytoma (AFH), with emphasis on differential diagnosis.

METHODSThe clinical and pathologic features were reviewed in 24 cases of AFH (from 2007 to 2012). The follow-up data were analyzed. Immunohistochemical study using EnVision method was carried out.

RESULTSThere were 10 males and 14 females with age at presentation ranging from 8 to 67 years (mean = 41 years and median = 39 years). The tumor occurred in the extremities (number = 14), trunk (number = 8) or head and neck region (number = 2). Apart from one case, all were located in the dermis. The clinical appearance was similar to those of classic fibrous histiocytoma. Histologically, the tumor was characterized by various number of hyperchromatic bizarre cells scattered in the background. Mitotic figures including atypical ones were noted, especially in the more cellular areas. Immunohistochemical study showed that the tumor cells expressed vimentin. Focal positivity for alpha-smooth muscle actin was demonstrated in some cases. Follow-up information was available in 14 cases. Three of them suffered local recurrence. None of these cases had distant metastasis.

CONCLUSIONSAtypical fibrous histiocytoma represents a pleomorphic variant of fibrous histiocytoma. Although the tumor exhibits worrisome features, it usually pursuits a relatively benign course. Nevertheless, rare cases may recur, especially after incomplete excision. AFH is sometimes mistaken as atypical fibroxanthoma. A distinction between the two entities is warranted as they represent two different entities.

Actins ; metabolism ; Adolescent ; Adult ; Aged ; Back ; pathology ; Child ; Diagnosis, Differential ; Extremities ; pathology ; Female ; Follow-Up Studies ; Histiocytoma, Benign Fibrous ; metabolism ; pathology ; surgery ; Humans ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Retrospective Studies ; Skin Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism ; Xanthomatosis ; pathology ; Young Adult

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

OBJECTIVETo investigate the clinicopathologic characteristics, differential diagnosis and biologic behaviors of pleomorphic rhabdomyosarcoma (PRMS).

METHODSThe clinical findings, pathological features and immunophenotypes were reviewed in 44 cases of PRMS (encountered during the period from 2005 to 2012). The clinical outcome was analyzed.

RESULTSThere were 33 males and 11 females with age ranging from 2 to 85 years (mean, 51 years; median, 55 years). Of 44 tumors, 22 occurred in the extremities (50.0%), 16 in the trunk (36.4%), 5 in the internal organs (11.4%), and 1 in the head and neck (2.2%). Histologically, 40 tumors showed features of pleomorphic sarcoma with striking resemblance to undifferentiated pleomorphic sarcoma (UPS)/malignant fibrous histiocytoma(MFH). However, variable amount of pleomorphic rhabdomyoblasts (PRMB) were identified in most cases. The remaining 4 tumors were composed predominantly of fascicles of spindle cells with interspersed PRMBs. Immunohistiochemically, tumor cells showed diffuse staining of desmin (41/41,100%), with variable expression of myogenin (18/32, 56.3%), MyoD1 (10/21, 47.6%) and MSA (21/29, 72.4%), whereas α-SMA was negative in most cases. Follow-up data (range, 2 to 51 months) available in 29 cases showed 12 patients were alive with unresectable or recurrent disease and 17 patients were alive with no evidence of disease. The median disease-free and overall survivals was 6.0 months (mean, 9.1 months) and 8.0 months (mean, 11.2 months) respectively. Thirteen patients (44.8%) exhibited progression of disease with recurrence in 4 cases and metastasis in 9 cases. The median interval to progression was 6.0 months (mean, 5.9 months).

CONCLUSIONSThe presence of pleomorphic cells with strong eosinphilic cytoplasm in a pleomorphic sarcoma is suggestive of a PRMS. Diffuse, strong expression of desmin and negative staining for α-SMA further facilitate the diagnosis of PRMS and its differential diagnosis from pleomorphic leiomyosarcoma. Although PRMS may affect children or adolescents, it should be cautious not to misdiagnose anaplastic rhabdomyosarcoma as PRMS. PRMS is a high-grade sarcoma with a poor prognosis.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Chemoradiotherapy, Adjuvant ; Chemotherapy, Adjuvant ; Child ; Child, Preschool ; Desmin ; metabolism ; Diagnosis, Differential ; Extremities ; Female ; Follow-Up Studies ; Histiocytoma, Malignant Fibrous ; metabolism ; pathology ; Humans ; Lung Neoplasms ; secondary ; Male ; Middle Aged ; MyoD Protein ; metabolism ; Myogenin ; metabolism ; Neoplasm Recurrence, Local ; Retrospective Studies ; Rhabdomyosarcoma ; metabolism ; pathology ; secondary ; surgery ; therapy ; Survival Rate ; Young Adult

Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Diagnosis, Differential ; Histiocytoma, Benign Fibrous ; metabolism ; pathology ; surgery ; Humans ; Male ; Middle Aged ; Neprilysin ; metabolism ; Receptors, Cell Surface ; metabolism ; Skin Neoplasms ; metabolism ; pathology ; surgery ; Thigh ; Vimentin ; metabolism

Actins ; metabolism ; Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Diagnosis, Differential ; Female ; Granuloma, Plasma Cell ; metabolism ; pathology ; Histiocytoma, Benign Fibrous ; diagnostic imaging ; metabolism ; pathology ; surgery ; Humans ; Lung Neoplasms ; diagnostic imaging ; metabolism ; pathology ; surgery ; Middle Aged ; Neprilysin ; metabolism ; Pneumonectomy ; methods ; Radiography ; Sarcoma ; metabolism ; pathology ; Solitary Fibrous Tumors ; metabolism ; pathology ; Vimentin ; metabolism ; Xanthomatosis ; metabolism ; pathology

OBJECTIVEto study the clinicopathologic features and differential diagnosis of low-grade central osteosarcoma (LGCOS).

METHODSnine cases of LGCOS were retrieved from the archival consultation files. The clinical, radiologic and pathologic features were analyzed, with literature review.

RESULTSthe mean age of the patients was 31 years. The male-to-female ratio was 3:6. All of the patients presented with painful mass and/or swelling. The sites of involvement included thigh (n = 4), tibia (n = 1), fibula (n = 1), cervical vertebra (n = 1), lumbar vertebra (n = 1) and maxilla (n = 1). Radiologic examination showed mixed lytic/blastic lesions with soft tissue shadow in 5 cases and associated periosteal reaction in 3 cases. The tumors were treated by surgical excision, with no adjuvant therapy given. The duration of follow up ranged from 2 to 43 months. Four cases had recurrence which occurred at 8 to 25 months after the operation. Gross examination showed that the tumors were fragmented on submission in 5 cases and en bloc in 4 cases. They had solid and firm cut surface, with various degree of grittiness. Histologically, LGCOS was characterized by the presence of hypocellular fibroblastic stroma associated with focal osteoid production. The spindly tumor cells showed mild degree of nuclear pleomorphism, with occasional mitotic figures demonstrated in all of the 9 cases. The newly formed neoplastic woven bone did not have any osteoblastic rimming. The bony trabeculae were slender and seam-like. Parallel arrays of woven bone were seen in 6 cases. Some of the bony trabeculae appeared irregularly branched and curved. The tumor cells permeated adjoining pre-existing bony trabeculae and bone marrow in all cases. Three cases also showed soft tissue involvement.

CONCLUSIONSLGCOS often posses important diagnostic pitfalls due to the relatively bland-looking tumor cell morphology and associated large woven or longitudinal seams of lamellar-like bone. Thorough understanding of the histologic features, when coupled with clinical and radiologic findings, are essential in arriving at a correct diagnosis.

Adolescent ; Adult ; Bone Neoplasms ; diagnostic imaging ; pathology ; surgery ; Diagnosis, Differential ; Female ; Fibrous Dysplasia of Bone ; pathology ; Fibula ; diagnostic imaging ; Histiocytoma, Benign Fibrous ; pathology ; Humans ; Magnetic Resonance Imaging ; Male ; Middle Aged ; Neoplasm Recurrence, Local ; Osteosarcoma ; diagnostic imaging ; pathology ; surgery ; Radiography ; Radionuclide Imaging ; Reoperation ; Thigh ; diagnostic imaging ; pathology ; Young Adult

Abdominal Neoplasms ; drug therapy ; metabolism ; pathology ; secondary ; surgery ; Dendritic Cell Sarcoma, Follicular ; drug therapy ; metabolism ; pathology ; surgery ; Dendritic Cell Sarcoma, Interdigitating ; metabolism ; pathology ; Diagnosis, Differential ; Female ; Gastrointestinal Stromal Tumors ; metabolism ; pathology ; Histiocytoma, Malignant Fibrous ; metabolism ; pathology ; Humans ; Middle Aged ; Neoplasm Recurrence, Local ; Omentum ; Peritoneal Neoplasms ; secondary ; Receptor, Epidermal Growth Factor ; metabolism ; Receptors, Complement 3b ; metabolism ; Receptors, Complement 3d ; metabolism

OBJECTIVETo study the clinicopathologic features, immunophenotype and differential diagnosis of angiomatoid fibrous histiocytoma (AFH).

METHODSThe clinicopathologic features of 5 cases of AFH were analyzed. Immunohistochemical study was carried out and the literature was reviewed.

RESULTSThere were a total of 3 males and 2 females. The average age of patients was 21.4 years old. The average duration of symptoms was 13 months. The patients primarily presented with a slowly enlarging painless deep dermal or subcutaneous mass. The mass was located in the head and neck region in 3 cases, elbow in 1 case and foot in 1 case. The patients underwent complete resection of the tumor, with no adjuvant chemotherapy and/or radiotherapy given. During a period of follow up for 10 to 29 months, all of them had no recurrence or distant metastasis. Gross examination showed that the tumor was well-circumscribed and had a grey-colored cut surface, with focal hemorrhagic cystic changes. The average tumor dimension was 1.9 cm. Histologically, the tumor was composed of histiocytoid or spindly cells arranged in nodular pattern. Fibrillary neuropil-type intercellular material was identified in all cases and a fibrous pseudocapsule surrounded by lymphocytes and plasma cells was demonstrated in 3 cases. Immunohistochemical study showed that all of them were positive for vimentin and negative for S-100 protein, pan-cytokeratin, CD34 and CD31. Three of the cases expressed desmin and CD68. Two cases were epithelial membrane antigen and CD99-positive.

CONCLUSIONSAFH is a rare tumor of intermediate malignant potential. Definitive diagnosis requires thorough histologic examination and clinical correlation. Immunohistochemistry is also helpful for diagnosis and differential diagnosis. Wide local excision with post-operative follow up is the main modality of treatment.

Adolescent ; Adult ; Aneurysm ; metabolism ; pathology ; Antigens, CD ; metabolism ; Antigens, Differentiation, Myelomonocytic ; metabolism ; Chemotherapy, Adjuvant ; Child ; Desmin ; metabolism ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Histiocytoma, Benign Fibrous ; metabolism ; pathology ; surgery ; Histiocytoma, Malignant Fibrous ; pathology ; Humans ; Male ; Radiotherapy, Adjuvant ; Soft Tissue Neoplasms ; metabolism ; pathology ; surgery ; Vimentin ; metabolism ; Young Adult