PURPOSE: A dedifferentiated chondrosarcoma is a rare lethal tumor characterized by a low grade chondrosarcoma juxtaposed with a high grade dedifferentiated sarcoma, such as osteosarcoma, fibrosarcoma. The aim of our study was to document the clinical manifestation and oncologic outcomes of a dedifferentiated chondrosarcoma. MATERIALS AND METHODS: This study identified 11 patients who were diagnosed and treated for dedifferentiated chondrosarcoma between January 2007 and December 2016. The identified cohort was then reviewed regarding age, sex, symptom onset, tumor location, magnetic resonance imagings (MRIs), surgical margin, and pathologic diagnosis. The time to local recurrence and/or metastasis, follow-up duration, and the patients' final status were analyzed. RESULTS: The patients were comprised of 7 males and 4 females with a mean age of 54 years (range, 33–80 years). The location of the tumor was in the femur in 6 cases, pelvis in 4 cases, and metatarsal in 1 case. The average tumor diameter was 12.7 cm (range, 6.0–26.1 cm). At the time of diagnosis, 2 patients showed pathologic fracture; 1 patient was Enecking stage IIA, 9 patients were stage IIB, and 1 patient was stage III. Eight patients were classified as a primary dedifferentiated chondrosarcoma and 3 patients were secondary. One of the primary lesions was misinterpreted initially as a low grade chondroid lesion by MRI and underwent curettage. Local recurrence occurred in 8 cases and distant metastasis occurred in 10 cases with a mean duration of 8 months (range, 2–23 months) and 7 months (range, 1–32 months), respectively. The three-year overall survival of patients with dedifferentiated chondrosarcoma was 18%, and 10 patients died due to disease progression. CONCLUSION: Dedifferentiated chondrosarcoma developed lung metastases in the early period of the clinical courses and the prognosis was dismal.
Chondrosarcoma ; Cohort Studies ; Curettage ; Diagnosis ; Disease Progression ; Female ; Femur ; Fibrosarcoma ; Follow-Up Studies ; Fractures, Spontaneous ; Humans ; Lung ; Magnetic Resonance Imaging ; Male ; Metatarsal Bones ; Neoplasm Metastasis ; Osteosarcoma ; Pathology ; Pelvis ; Prognosis ; Recurrence ; Sarcoma

Small round cell tumors (SRCTs) are a heterogeneous group of neoplasms composed of small, primitive, and undifferentiated cells sharing similar histology under light microscopy. SRCTs include Ewing sarcoma/peripheral neuroectodermal tumor family tumors, neuroblastoma, desmoplastic SRCT, rhabdomyosarcoma, poorly differentiated round cell synovial sarcoma, mesenchymal chondrosarcoma, small cell osteosarcoma, small cell malignant peripheral nerve sheath tumor, and small cell schwannoma. Non-Hodgkin\'s malignant lymphoma, myeloid sarcoma, malignant melanoma, and gastrointestinal stromal tumor may also present as SRCT. The current shift towards immunohistochemistry and cytogenetic molecular techniques for SRCT may be inappropriate because of antigenic overlapping or inconclusive molecular results due to the lack of differentiation of primitive cells and unavailable genetic service or limited moleculocytogenetic experience. Although usage has declined, electron microscopy (EM) remains very useful and shows salient features for the diagnosis of SRCTs. Although EM is not always required, it provides reliability and validity in the diagnosis of SRCT. Here, the ultrastructural characteristics of SRCTs are reviewed and we suggest that EM would be utilized as one of the reliable modalities for the diagnosis of undifferentiated and poorly differentiated SRCTs.
Chondrosarcoma, Mesenchymal ; Cytogenetics ; Diagnosis ; Gastrointestinal Stromal Tumors ; Genetic Services ; Humans ; Immunohistochemistry ; Lymphoma ; Melanoma ; Microscopy ; Microscopy, Electron ; Microscopy, Electron, Transmission* ; Neurilemmoma ; Neuroblastoma ; Neuroectodermal Tumors ; Osteosarcoma ; Pathology ; Peripheral Nerves ; Reproducibility of Results ; Rhabdomyosarcoma ; Sarcoma, Myeloid ; Sarcoma, Synovial

Any medical diagnosis should take a multimodal approach, especially those involving tumour-like conditions, as entities that mimic neoplasms have overlapping features and may present detrimental outcomes if they are underdiagnosed. These case reports present diagnostic pitfalls resulting from overdependence on a single diagnostic parameter for three musculoskeletal neoplasm mimics: brown tumour (BT) that was mistaken for giant cell tumour (GCT), methicillin-resistant Staphylococcus aureus osteomyelitis mistaken for osteosarcoma and a pseudoaneurysm mistaken for a soft tissue sarcoma. Literature reviews revealed five reports of BT simulating GCT, four reports of osteomyelitis mimicking osteosarcoma and five reports of a pseudoaneurysm imitating a soft tissue sarcoma. Our findings highlight the therapeutic dilemmas that arise with musculoskeletal mimics, as well as the importance of thorough investigation to distinguish mimickers from true neoplasms.
Adult ; Aneurysm, False ; diagnosis ; Biopsy ; Bone Diseases ; diagnosis ; Bone Diseases, Metabolic ; diagnosis ; Bone Neoplasms ; diagnosis ; Cell Proliferation ; Diagnosis, Differential ; Diagnostic Errors ; prevention & control ; Female ; Giant Cell Tumors ; diagnosis ; Humans ; Hyperparathyroidism ; complications ; Leukocytosis ; diagnosis ; Male ; Methicillin-Resistant Staphylococcus aureus ; Middle Aged ; Neoplasms ; diagnosis ; microbiology ; Osteomyelitis ; diagnosis ; microbiology ; Osteosarcoma ; diagnosis ; Sarcoma ; diagnosis ; Soft Tissue Neoplasms ; diagnosis ; Tibia ; pathology

OBJECTIVETo analyze the clinical features and treatment of skull base osteosarcoma.

METHODSThe clinical data of 18 patients with skull base osteosarcoma, who were admitted to the CAMS Cancer Hospital from January 2005 to November 2013, were retrospectively analyzed. The patients were followed up by telephone, outpatient review and other means. Fifteen patients were followed up, 4 cases received surgery only, and 11 cases received surgery with adjuvant chemotherapy and/or radiotherapy. Kaplan-Meier survival curve analysis was used to analyze the clinical data and Log rank method was used for verification.

RESULTSNine patients died among the 15 patients who were followed up for 3-103 months (mean 25.0 months): seven patients died of local recurrence, and two patients died of distant metastasis, and six patients were still alive. Four patients received surgery only, with a median survival time of 25.0 months, and 11 patients received comprehensive treatment, with a median survival time of 47.0 months (P = 0.02). Five patients received sub-total resection, with a mean survival time of 47.0 months, and 10 patients received total resection, with a mean survival time of 45.0 months (P = 0.37). The 1- and 2-year recurrence rates were 46.6% and 68.9%, respectively. The overall 1-, 2-, 3- and 5-year survival rates were 82.4%, 61.8%, 36.0% and 36.0%, respectively, with a median survival time of 30.0 months.

CONCLUSIONSTo compare the long bone and head and neck osteosarcoma with skull base osteosarcoma, the skull base osteosarcoma has a lower total resection rate, a higher recurrence rate, and a poorer prognosis. Radical surgery and comprehensive treatment are appropriate for skull base osteosarcoma.

Bone Neoplasms ; diagnosis ; pathology ; therapy ; Chemotherapy, Adjuvant ; Combined Modality Therapy ; Humans ; Kaplan-Meier Estimate ; Neoplasm Recurrence, Local ; Osteosarcoma ; diagnosis ; pathology ; therapy ; Retrospective Studies ; Skull Base ; pathology ; Survival Rate

Malignant kidney neoplasms are the most frequently encountered solid kidney masses. Although renal cell carcinoma is the major renal malignancy, other solid malignant renal masses should be considered in the differential diagnosis of solid renal masses that do not contain a macroscopic fatty component. In this pictorial essay, we present the imaging findings of a primitive neuroectodermal tumor, primary liposarcoma of the kidney, primary neuroendocrine tumor, leiomyosarcoma, synovial sarcoma, malignant fibrous histiocytoma, sclerosing fibrosarcoma and renal metastasis of osteosarcoma.
Bone Neoplasms/secondary ; Carcinoma, Renal Cell/pathology/radiography ; Diagnosis, Differential ; Fibrosarcoma/radiography ; Histiocytoma/radiography ; Humans ; Kidney Neoplasms/*pathology/radiography ; Leiomyosarcoma/pathology/radiography ; Magnetic Resonance Imaging ; Middle Aged ; Neuroectodermal Tumors, Primitive/pathology/radiography ; Osteosarcoma/pathology ; Sarcoma ; Sarcoma, Synovial/radiography ; Tomography, X-Ray Computed

OBJECTIVETo study the clinicopathologic features and differential diagnosis of giant cell-rich osteosarcoma (GCRO) and giant cell tumor of bone (GCT).

METHODSThe clinical, radiologic, pathologic and immunohistochemical features of 18 cases of GCRO and 118 cases of GCT were evaluated.

RESULTSThe mean age of patients with GCRO was 24.6 years. Fifteen of the 18 cases arose in the metaphysis of long bones. GCRO presented as a large poorly-defined mixed lytic and blastic mass, associated with cortical destruction and formation of large soft tissue component. Histologically, GCRO was characterized by a predominance of numerous osteoclast-like giant cells admixed with scanty osteoid which was formed by neoplastic cells in different levels of anaplasia and pleomorphism. In the 118 cases of GCT studied, the mean age of patients was 34.5 years. Most of them (108 cases) arose in the epiphyseal region of long bones. They usually presented as expansile eccentric and osteolytic lesions. Invasive GCT displayed local cortical destruction. Histologic examination of GCT revealed the presence of large number of osteoclast-like giant cells and mononuclear stromal cells. The mononuclear stromal cells possessed poorly defined cytoplasm, showed little cytological atypia and did not carry atypical mitotic figures. They were positive for p63 (83.9%, 99/118). Reactive bone could be observed at the periphery.

CONCLUSIONSGCRO represents a special form of osteosarcoma which shows overlapping clinicopathologic features with invasive GCT. The presence of nuclear atypia, atypical mitoses and osteoid matrix produced directly by neoplastic cells are more in favor of GCRO. These features however may not be demonstrated in full in limited small biopsy samples. It is thus important to analyze all clinical, radiologic and pathologic features before a definitive diagnosis is made.

Adult ; Bone Neoplasms ; diagnosis ; pathology ; Diagnosis, Differential ; Giant Cell Tumor of Bone ; diagnosis ; pathology ; Giant Cells ; pathology ; Humans ; Osteosarcoma ; diagnosis ; pathology

12E7 Antigen ; Antigens, CD ; metabolism ; Cell Adhesion Molecules ; metabolism ; Diagnosis, Differential ; Humans ; Kidney Neoplasms ; metabolism ; pathology ; surgery ; Male ; Middle Aged ; Nephrectomy ; Osteosarcoma ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

Chondroblastoma ; pathology ; Chondroma ; pathology ; Chondrosarcoma ; metabolism ; pathology ; surgery ; Cricoid Cartilage ; Diagnosis, Differential ; Humans ; Laryngeal Neoplasms ; metabolism ; pathology ; surgery ; Laryngectomy ; Lymph Node Excision ; Male ; Middle Aged ; Osteoblastoma ; pathology ; Osteosarcoma ; pathology ; S100 Proteins ; metabolism ; Sarcoma, Clear Cell ; metabolism ; pathology ; surgery ; Vimentin ; metabolism

Breast metastases are uncommon and typically spread from contralateral breast carcinomas. Breast metastases that spread from extramammary malignancies are even less common, and account for 0.5%-6.6% of all malignant breast disease. As extrapulmonary metastases from osteosarcoma are uncommon, breast metastasis from osteosarcoma is extremely rare. We report a case of breast and peritoneal metastases from a tibial osteosarcoma 18 months after diagnosis, and 9 months after surgery and adjuvant chemotherapy. Computed tomography findings of multiple calcified and noncalcified tumour deposits in the lungs, pleura, peritoneum, chest wall and both breasts are described.
Adolescent ; Bone Neoplasms ; diagnosis ; diagnostic imaging ; pathology ; Breast Neoplasms ; diagnostic imaging ; secondary ; Female ; Humans ; Neoplasm Metastasis ; Osteosarcoma ; diagnosis ; diagnostic imaging ; pathology ; Peritoneal Neoplasms ; diagnostic imaging ; secondary ; Tomography, X-Ray Computed

OBJECTIVETo compare the pathologic diagnosis and immunohistochemistry of small cell malignant tumors (SCMT) of bone using both core needle biopsy and surgical specimen.

METHODSSeventy-seven cases of SCMT with core needle biopsies and surgical specimens available were respectively analyzed by histologic examination and immunohistochemical study, with literature review.

RESULTSThe male-to-female ratio was 48:29. The age of the patients ranged from 6 to 73 years. The tumors studied included Ewing sarcoma/PNET (n = 38), myeloma (n = 23), lymphoma (n = 10), small cell osteosarcoma (n = 2), small cell carcinoma (n = 2) and mesenchymal chondrosarcoma (n = 2). The tumors involved limbs, axial skeleton and flat bones. Microscopically, the tumors shared similar histology, with small round cells and spindly cells arranged in diffuse sheets. The pathologic diagnosis by core needle biopsies correlated with that by surgical specimens in 84.4% (65/77) of the cases.

CONCLUSIONSSCMT represents a heterogeneous group of malignancy. Correlations with clinicoradiologic findings and application of ancillary investigations including immunohistochemistry and molecular study are important for definitive diagnosis. Pathologic diagnosis using core needle biopsies shows good results and provides useful information for surgical planning.

12E7 Antigen ; Adolescent ; Adult ; Aged ; Antigens, CD ; metabolism ; Biopsy, Large-Core Needle ; Bone Neoplasms ; diagnosis ; metabolism ; pathology ; Carcinoma, Small Cell ; diagnosis ; metabolism ; pathology ; Cell Adhesion Molecules ; metabolism ; Child ; Female ; Humans ; Lymphoma ; diagnosis ; metabolism ; pathology ; Male ; Middle Aged ; Neuroectodermal Tumors, Primitive, Peripheral ; diagnosis ; metabolism ; pathology ; Oncogene Proteins, Fusion ; metabolism ; Osteosarcoma ; diagnosis ; metabolism ; pathology ; Plasmacytoma ; diagnosis ; metabolism ; pathology ; Proto-Oncogene Protein c-fli-1 ; metabolism ; RNA-Binding Protein EWS ; metabolism ; Retrospective Studies ; Sarcoma, Ewing ; diagnosis ; metabolism ; pathology ; Vimentin ; metabolism ; Young Adult