Parosteal osteosarcoma with low grade chondrosarcoma and liposarcoma components. A rare histologic variant. Case report and literature review.

INTRODUCTION: conventional parosteal osteosarcoma is an uncommon malignant bone tumor, comprising 4% of all osteosarcomas. Although rare, parosteal osteosarcoma is the most common type of osteosarcoma of the bone surface. We present the clinical, histological and imaging characteristics of a rare histologic variant of a parosteal osteosarcoma, review the literature and emphasize the importance of radio-pathological correlation as well as the interpretation of a representative biopsy in order to obtain the correct diagnosis. CASE REPORT: a 36-year old woman began her condition one year prior to admission to the hospital with increased volume in the left knee and pain. Image studies showed a juxtacortical heterogeneous tumor localized on the posterior surface of the distal femoral metaphysis. An incisional biopsy was performed, with the diagnosis of a Parosteal Osteosarcoma and a wide surgical resection was undertaken. According to the findings of the surgical specimen, the diagnosis of a Parosteal Osteosarcoma with low grade chondrosarcoma and liposarcoma components was made. The knowledge of this rare parosteal osteosarcoma variant can lead the orthopedic oncologists to avoid overlooking the adipose component and provide adequate surgical margins. CONCLUSION: we present the clinical, histological and imaging characteristics of a Parosteal Osteosarcoma with low grade liposarcoma and chondrosarcoma components.

INTRODUCCIÓN: el osteosarcoma parosteal convencional es un tumor óseo maligno poco común, que comprende el 4% de todos los osteosarcomas. Aunque es poco común, el osteosarcoma parosteal es el tipo más común de osteosarcoma de la superficie ósea. Presentamos las características clínicas, histológicas y de imagen de una variante histológica rara de un osteosarcoma parosteal, revisamos la literatura y enfatizamos la importancia de la correlación radio-patológica, así como la interpretación de una biopsia representativa para obtener el diagnóstico correcto. REPORTE DE CASO: mujer de 36 años inició su cuadro un año antes de su ingreso al hospital con aumento de volumen en rodilla izquierda y dolor. Los estudios de imagen mostraron una tumoración heterogénea yuxtacortical localizada en la superficie posterior de la metáfisis femoral distal. Se realizó biopsia incisional, con diagnóstico de osteosarcoma parosteal y se realizó resección quirúrgica amplia. De acuerdo con los hallazgos de la pieza quirúrgica se realizó el diagnóstico de osteosarcoma parosteal con componentes de condrosarcoma y liposarcoma de bajo grado. El conocimiento de esta rara variante de osteosarcoma parosteal puede llevar a los ortopedistas oncólogos a considerar otros componentes y proporcionar márgenes quirúrgicos adecuados. CONCLUSIÓN: presentamos las características clínicas, histológicas y de imagen de un osteosarcoma parosteal con componentes de liposarcoma y condrosarcoma de bajo grado.

Dedifferentiated Primary Parosteal Osteosarcoma of the Temporal Bone in a 19-Year-Old Patient: A Case Report.

Osteosarcoma is the most common primary malignant tumor affecting the bone but is a rare occurrence in the head and neck region. Complete surgical resection with wide surgical margins is currently the main treatment strategy for osteosarcoma but can be hard to achieve due to the complex anatomy of the head and neck. We report the first case of primary high-grade dedifferentiated parosteal osteosarcoma arising from the temporal bone in published literature. The 19-year-old patient presented with a left retroauricular lesion measuring 3 cm in diameter. Radiographic imaging and biopsy suggested the diagnosis of intermediate-grade chondrosarcoma, but definitive histopathology confirmed a diagnosis of dedifferentiated parosteal osteosarcoma. The tumor was resected with wide margins, removing the underlying temporal bone, periosteum and overlying soft tissue through a lateral temporal bone resection. The middle ear was reconstructed with cartilage grafting, and the dura of the posterior and middle cranial fossa was covered using temporal fascia grafts and local transpositional flaps. The patient is recurrence free 10 months after treatment. This report was assembled following CARE [The CARE guidelines (for Case Reports)] guidelines and describes clinical, histological, and radiological manifestations of our patient's rare clinical entity and may provide more data in treating patients with osteosarcoma affecting the anatomically complex head-and-neck region.

Parosteal osteosarcoma of the thumb: A case report and literature review.

Parosteal osteosarcoma (PO) is a rare malignant tumor arising from the surface of the bone. Locations in the hand are even more exceptional. This low-grade osteosarcoma shows non-specific clinical and radiological presentation, making diagnosis challenging. Moreover, histologic examination is extremely difficult and can easily lead to misdiagnosis. We report the case of a 21-year-old woman who presented PO of the right thumb, initially diagnosed as a "benign exostosis" 9 years previously. En-bloc resection followed by reconstruction using a free corticocancellous iliac crest autograft provided good esthetic and functional outcome. No recurrence occurred at 2 years' follow-up. Our literature review confirmed the rarity of PO of the hand, with only 8 cases reported in the past 60 years. Amputation was the main treatment, but some authors reported limb-sparing surgery. The present result and those in the literature review support conservative surgery when feasible, with little recurrence and better functional and esthetic results. These rare tumors should not be misdiagnosed, and should be treated in specialized centers to optimize outcome.

Parosteal Osteosarcoma: A Benign-Looking Tumour, Amenable to a Variety of Surgical Reconstruction.

Osteosarcoma arising from cortical surface is classified into parosteal, periosteal and high-grade surface osteosarcoma. Along the spectrum, parosteal osteosarcoma occupies the well-differentiated end. It is a relatively rare disease entity, comprised only 4% of all osteosarcomas and barely reported in the literature. The objective of this study is to describe cases of parosteal osteosarcoma as well as a variety of treatment options amenable to such entity. Six cases of parosteal osteosarcoma were identified based on histopathological reports in a tertiary referral hospital in Jakarta, Indonesia between January 2001 and December 2019. The mean age was 29.8 years old; four of them (66.7%) were male. Distal end of femur was the most commonly involved bone (five cases, 83.3%). The patients were treated with wide excision followed by several different reconstruction methods: replacement with endoprosthesis, extracorporeal irradiation, knee arthrodesis, or prophylactic fixation. One of our patients presented with dedifferentiated component, and therefore was treated by limb ablation. While two cases died of pulmonary metastasis, other patients reported fair to excellent functional outcome.

[Dedifferentiated diaphyseal juxtacortical osteosarcoma of ulna with metastasis to the lung]. / Osteosarcoma parostal desdiferenciado en diáfisis de cúbito metastásico a pulmón.

Dedifferentiated parosteal osteosarcoma is a variant in which a high grade osteosarcoma coexists with a parosteal osteosarcoma. We report the case of a 20-year-old female patient who presented with six months of evolution of pain and functional limitation of the right forearm, with no apparent cause; radiographs were performed, observing a tumoral lesion in the diaphysis of the right ulna. Physical examination showed pain upon palpation in the diaphysis of the ulna and limitation of prone-supination. Axial computed tomography of the thorax revealed metastatic disease in the upper lobe of the left lung. An incisional biopsy was performed on the right ulna, with a report of dedifferentiated parosteal osteosarcoma. Therefore, the patient was managed with neoadjuvant chemotherapy with cisplatin and doxorubicin until completing three cycles. Surgical treatment consisted of intercalary resection of the diaphysis of the right ulna, plus reconstruction of the microvascularized autologous graft of the right fibular diaphysis and graft stabilization with 3.5 mm dynamic compression plate (DCP) and one-third tubular plate. In the same procedure, pulmonary metastasectomy was performed by thoracoscopy. Post-surgical histopathological report with 100% necrosis. Currently, the patient is asymptomatic, with no evidence of tumor activity. Dedifferentiated parosteal osteosarcoma is a rare pathology, but should be suspected as a differential diagnosis in the presence of a parosteal osteosarcoma; it should be taken into account that this disease can metastasize due to its dedifferentiated pattern. It is important to plan a surgical treatment that allows an adequate functional reconstruction, always taking into account the oncological principle.

El osteosarcoma parostal desdiferenciado es una variante en la cual un osteosarcoma de alto grado coexiste con un osteosarcoma parostal. Se presenta el caso de un paciente femenino de 20 años; acudió con seis meses de evolución de dolor y limitación funcional en el antebrazo derecho sin causa aparente; se le realizaron radiografías, donde se observó una lesión tumoral en la diáfisis del cúbito derecho. A la exploración física, presentó dolor a la palpación en la diáfisis del cúbito y limitación a la pronosupinación. La tomografía axial computada de tórax reveló enfermedad metastásica en el lóbulo superior del pulmón izquierdo. Se le efectuó una biopsia incisional de la tumoración en el cúbito derecho, con reporte de osteosarcoma parostal desdiferenciado. Por ello, inició manejo con quimioterapia neoadyuvante con cisplatino y doxorrubicina hasta completar tres ciclos. El tratamiento quirúrgico consistió en resección intercalar de la diáfisis del cúbito derecho más reconstrucción de injerto autólogo microvascularizado de la diáfisis del peroné derecho y estabilización del injerto con placa de compresión dinámica (DCP) 3.5 mm y placa tercio de caña. En el mismo procedimiento se le efectuó metastasectomía pulmonar por toracoscopía. El reporte histopatológico postquirúrgico, con necrosis de 100%. Actualmente, la paciente se encuentra asintomática, sin datos de actividad tumoral. El osteosarcoma parostal desdiferenciado es una patología rara, pero que se debe sospechar como diagnóstico diferencial ante un osteosarcoma parostal; se debe tener en cuenta que esta enfermedad puede generar metástasis por su patrón desdiferenciado. Es importante planificar un tratamiento quirúrgico que permita una adecuada reconstrucción funcional, siempre teniendo en cuenta el principio oncológico.

Osteosarcoma parostal desdiferenciado en diáfisis de cúbito metastásico a pulmón / Dedifferentiated diaphyseal juxtacortical osteosarcoma of ulna with metastasis to the lung

Resumen: El osteosarcoma parostal desdiferenciado es una variante en la cual un osteosarcoma de alto grado coexiste con un osteosarcoma parostal. Se presenta el caso de un paciente femenino de 20 años; acudió con seis meses de evolución de dolor y limitación funcional en el antebrazo derecho sin causa aparente; se le realizaron radiografías, donde se observó una lesión tumoral en la diáfisis del cúbito derecho. A la exploración física, presentó dolor a la palpación en la diáfisis del cúbito y limitación a la pronosupinación. La tomografía axial computada de tórax reveló enfermedad metastásica en el lóbulo superior del pulmón izquierdo. Se le efectuó una biopsia incisional de la tumoración en el cúbito derecho, con reporte de osteosarcoma parostal desdiferenciado. Por ello, inició manejo con quimioterapia neoadyuvante con cisplatino y doxorrubicina hasta completar tres ciclos. El tratamiento quirúrgico consistió en resección intercalar de la diáfisis del cúbito derecho más reconstrucción de injerto autólogo microvascularizado de la diáfisis del peroné derecho y estabilización del injerto con placa de compresión dinámica (DCP) 3.5 mm y placa tercio de caña. En el mismo procedimiento se le efectuó metastasectomía pulmonar por toracoscopía. El reporte histopatológico postquirúrgico, con necrosis de 100%. Actualmente, la paciente se encuentra asintomática, sin datos de actividad tumoral. El osteosarcoma parostal desdiferenciado es una patología rara, pero que se debe sospechar como diagnóstico diferencial ante un osteosarcoma parostal; se debe tener en cuenta que esta enfermedad puede generar metástasis por su patrón desdiferenciado. Es importante planificar un tratamiento quirúrgico que permita una adecuada reconstrucción funcional, siempre teniendo en cuenta el principio oncológico.

Abstract: Dedifferentiated parosteal osteosarcoma is a variant in which a high grade osteosarcoma coexists with a parosteal osteosarcoma. We report the case of a 20-year-old female patient who presented with six months of evolution of pain and functional limitation of the right forearm, with no apparent cause; radiographs were performed, observing a tumoral lesion in the diaphysis of the right ulna. Physical examination showed pain upon palpation in the diaphysis of the ulna and limitation of prone-supination. Axial computed tomography of the thorax revealed metastatic disease in the upper lobe of the left lung. An incisional biopsy was performed on the right ulna, with a report of dedifferentiated parosteal osteosarcoma. Therefore, the patient was managed with neoadjuvant chemotherapy with cisplatin and doxorubicin until completing three cycles. Surgical treatment consisted of intercalary resection of the diaphysis of the right ulna, plus reconstruction of the microvascularized autologous graft of the right fibular diaphysis and graft stabilization with 3.5 mm dynamic compression plate (DCP) and one-third tubular plate. In the same procedure, pulmonary metastasectomy was performed by thoracoscopy. Post-surgical histopathological report with 100% necrosis. Currently, the patient is asymptomatic, with no evidence of tumor activity. Dedifferentiated parosteal osteosarcoma is a rare pathology, but should be suspected as a differential diagnosis in the presence of a parosteal osteosarcoma; it should be taken into account that this disease can metastasize due to its dedifferentiated pattern. It is important to plan a surgical treatment that allows an adequate functional reconstruction, always taking into account the oncological principle.

On the importance of considering disease subtypes: Earliest detection of a parosteal osteosarcoma? Differential diagnosis of an osteosarcoma in an Anglo-Saxon female.

A case of potentially dedifferentiated parosteal osteosarcoma was found in the proximal humerus of an adult female buried in the late Anglo-Saxon cemetery of Cherry Hinton, Cambridgeshire, UK. Key features include a large, dense, lobulated mass attached to the medial metaphysis of the proximal humerus by a broad-based attachment, accompanied by cortical destruction and widespread spiculated periosteal reaction. Radiographic images confirm medullary involvement, lack of continuity between the cortex and external mass, a radiolucent cleavage plane and possible radiolucent zones within the bony masses. Differential diagnoses considered include osteochondroma, myositis ossificans, fracture callus, as well as the primary malignancies of osteosarcoma and chondrosarcoma, and their various subtypes. The macroscopic and radiographic analysis of the tumor is described and discussed within clinical and paleopathological contexts. One of only 19 uncontested examples of osteosarcoma from past human populations, most of which remain unconfirmed, this case represents what we believe to be the earliest, and probably singular, bioarcheological example of parosteal osteosarcoma in human history.

Parosteal osteosarcoma of mandible: A rare case report.

With the exception of multiple myelomas, osteosarcoma is the most frequently occurring primary malignant bone tumor with an overall incidence of 1:100,000/year. It has greatest predilection for the metaphyses, most frequently femur and tibia. However, osteosarcomas affecting the craniofacial bones are infrequent. Two main types: intramedullary and juxtacortical varieties are seen. Juxtacortical variety is further subdivided into periosteal and parosteal variants. Due to its rarity, only 13 cases of parosteal osteosarcoma have been reported till date. A 35-year-old male patient with affected postirradiated mandible is being reported as the 14th case of this kind with its unique benign presentation and less aggressive nature.

Recurrence of juxtacortical chondrosarcoma arising on the rib.

Juxtacortical chondrosarcoma developing on the surface of a bone is quite rare. We report a case of juxtacortical chondrosarcoma arising on the fourth rib of a 76-year-old man. Intraregional tumor resection was performed, but local recurrence was detected after 6 months. The patient underwent wide resection including the ribs, and reconstruction of the thoracic wall. He was released with a good prognosis after a year. This case emphasizes the importance of biopsy analysis before surgery to carefully evaluate tumor spread in the cartilage and performing wide resection even if the tumor is easily separated from the bone.

The prognostic and therapeutic factors which influence the oncological outcome of parosteal osteosarcoma.

The aim of this study was to evaluate the prognostic and therapeutic factors which influence the oncological outcome of parosteal osteosarcoma. A total of 80 patients with a primary parosteal osteosarcoma were included in this retrospective study. There were 51 females and 29 males with a mean age of 29.9 years (11 to 78). The mean follow-up was 11.2 years (1 to 40). Overall survival was 91.8% at five years and 87.8% at ten years. Local recurrence occurred in 14 (17.5%) patients and was associated with intralesional surgery and a large volume of tumour. On histological examination, 80% of the local recurrences were dedifferentiated high-grade tumours. A total of 12 (14.8%) patients developed pulmonary metastases, of whom half had either a dedifferentiated tumour or a local recurrence. Female gender and young age were good prognostic factors. Local recurrence was a poor prognostic factor for survival. Medullary involvement or the use of chemotherapy had no impact on survival. The main goal in treating a parosteal osteosarcoma must be to achieve a wide surgical margin, as inadequate margins are associated with local recurrence. Local recurrence has a significant negative effect on survival, as 80% of the local recurrences are high-grade dedifferentiated tumours, and half of these patients develop metastases. The role of chemotherapy in the treatment of parosteal osteosarcoma is not as obvious as it is in the treatment of conventional osteosarcoma. The mainstay of treatment is wide local excision.

Periosteal osteosarcoma of the mandible: a case report.

This report describes a rare case of a periosteal osteosarcoma of the mandible in a 50-year-old African-American woman who showed no underlying bony changes at panoramic radiography or computed tomography. This report describes the diagnostic workup used to obtain the definitive diagnosis and the surgical treatment and recommended method for subsequent tumor surveillance. Emphasis is placed on distinguishing periosteal osteosarcomas as a separate entity from conventional intraosseous osteosarcomas in the head and neck region.

Precise resection and biological reconstruction under navigation guidance for young patients with juxta-articular bone sarcoma in lower extremity: preliminary report.

BACKGROUND: It is a challenge to perform a joint-preserving resection for young patients with juxta-articular bone sarcomas. We determined whether osteotomy under image-guided navigation make joint-saving resection possible for juxta-articular lesions while adhering oncological principles. METHODS: Between June 2008 and July 2010, joint-preserving limb salvage surgeries were performed on 9 patients with juxta-articular bone sarcomas under navigation guidance. Computed tomography/magnetic resonance imaging fusion images were used for real-time navigation. Eight lesions located around the knee and 1 in hip. Six tumors extend to and 3 beyond the epiphyseal line. Planned osteotomy under image-guided navigation was employed for achieving clear surgical margin while maximizing host tissue preservation. All tumors were en bloc removed and intercalary defect were reconstructed by combination of allograft with vascularized fibula graft. All specimens were examined for resection margin. Patients were followed up for an average of 25.2 months for evaluating of functional and oncology outcomes. RESULTS: Entire joint were preserved in 6 patients and part of joint were saved in another 3 patients. The mean registration error for navigation was 0.40 mm (range, 0.31 to 0.62 mm). Clear surgical margin was obtained in all specimens. The average closest distance between the osteotomy line and tumor edge was 9.6 mm (range, 6 to 14 mm). Entire joint cartilage was preserved in 6 patients and portion of joint were saved in 3 patients (2 in proximal tibia, 1 in distal femur). No patient experienced local recurrence. Two patients developed lung metastasis. One died of disease and the other underwent metastasectomy and had no evidence of disease at the most recent follow-up. All reconstruction was in situ with the Musculoskeletal Tumor Society average score of 26.7 at final follow-up. CONCLUSIONS: With careful patient selection, image navigation-assisted surgery made it possible to resect the bone exactly as planned in length and orientation in the magnetic resonance imaging image, yielding a clear margin and preserving the entire or part of the articular cartilage in joint-sparing limb salvage procedures for treating skeletally immature patients with juxta-articular bone sarcomas. LEVEL OF EVIDENCE: Level IV--therapeutic study.

Imaging features of juxtacortical chondroma in children.

BACKGROUND: Juxtacortical chondroma is a rare benign bone lesion in children. Children usually present with a mildly painful mass, which prompts diagnostic imaging studies. The rarity of this condition often presents a diagnostic challenge. Correct diagnosis is crucial in guiding surgical management. OBJECTIVE: To describe the characteristic imaging findings of juxtacortical chondroma in children. MATERIALS AND METHODS: We identified all children who were diagnosed with juxtacortical chondroma between 1998 and 2012. A single experienced pediatric radiologist reviewed all diagnostic imaging studies, including plain radiographs, CT, MR and bone scans. RESULTS: Seven children (5 boys and 2 girls) with juxtacortical chondroma were identified, ranging in age from 6 years to 16 years (mean 12.3 years). Mild pain and a palpable mass were present in all seven children. Plain radiographs were available in 6/7, MR in 7/7, CT in 4/7 and skeletal scintigraphy in 5/7 children. Three lesions were located in the proximal humerus, with one each in the distal radius, distal femur, proximal tibia and scapula. Radiographic and CT features deemed highly suggestive of juxtacortical chondroma included cortical scalloping, underlying cortical sclerosis and overhanging margins. MRI features consistent with juxtacortical chondroma included isointensity to skeletal muscle on T1, marked hyperintensity on T2 and peripheral rim enhancement after contrast agent administration. One of seven lesions demonstrated intramedullary extension, and 2/7 showed adjacent soft-tissue edema. CONCLUSION: Juxtacortical chondroma is an uncommon benign lesion in children with characteristic features on plain radiographs, CT and MR. Recognition of these features is invaluable in guiding appropriate surgical management.

[Parosteal osteosarcomas: unusual findings]. / Osteosarcomas parostales: resultados infrecuentes.

OBJECTIVE: To study and evaluate the unusual findings in the natural history of parosteal osteosarcomas. Parosteal osteosarcomas are well-differentiated tumours of low grade malignancy, but may dedifferentiate into a more aggressive lesion. MATERIAL AND METHODS: We reviewed 7 parosteal osteosarcomas treated in La Paz Hospital between 2005 and 2009 (3 were dedifferentiated parosteal osteosarcomas). The authors analysed the clinical and radiological features, histology, treatment and outcomes in this patient group. RESULTS: There were 5 men and 2 women, with a mean age of 32.14 years, range 24-47 years. Three of seven tumours (42.8%) were dedifferentiated osteosarcomas. All three patients received chemotherapy. One patient presented with pulmonary metastases. No patient died. CONCLUSIONS: It is important to understand that the biological phenomenon of dedifferentiation can occur in parosteal osteosarcomas. The prognosis, treatment and survival changes radically.

Local recurrence of a parosteal osteosarcoma 21 years after incomplete resection.

Parosteal osteosarcoma (POS) is the most common form of surface osteosarcoma. Its symptoms are insidious and its duration prior to diagnosis is considerably longer than that of other types of osteosarcoma. We report a case of POS with a growing mass but no evidence of metastasis. This tumor, which was diagnosed as calcified hematoma with benign characteristics, was incompletely resected in our hospital 21 years before the diagnosis of recurrence. The patient underwent a wide en bloc resection in our hospital and was free of symptoms, with no signs of tumor recurrence or metastasis during a 53-month follow-up.

Parosteal osteosarcoma: report of a case and review of the literature.

Parosteal osteosarcoma is a rare malignancy of the bone that usually arises in the long bones. Involvement of the oral cavity is rare. Only 12 cases of intraoral parosteal osteosarcoma have been reported in the English language literature. This paper defines the major clinical, radiographic and histologic features of parosteal osteosarcoma and illustrates these with a case of a 33-year-old male presenting with a three-month history of a painless enlarging lump in the right maxilla. A critical and comprehensive review of the English language literature is also provided.

[Bizarre parosteal osteochondromatous proliferation or Nora's lesion]. / Prolifération ostéocartilagineuse parostéale bizarre ou lésion de Nora.

Bizarre parosteal osteochondromatous proliferation (BPOP) is a very rare benign lesion on face bones. The first line treatment is surgical exeresis. The frequency of recurrence after exeresis may suggest a malignancy.

Parosteal osteosarcoma.

In this retrospective clinical study, 6 cases of osteosarcoma of the bone have been analyzed. Five patients were with parosteal osteosarcoma and one with periosteal osteosarcoma. The study was performed at the Clinic for Orthopaedic Surgery in Skopje, Macedonia, from 1995 to 2005. This tumor represents 1.5% of all primary bone tumors treated at the Clinic in the 11 year period. The age of the 6 patients (2 female and 4 male) ranged from 8 to 39 years (average 23.8). The history analysis of the patients showed misinterpreted diagnosis in 50% of the cases, with 83.3% rate of local recurrence, 33.3% of metastases and 33.3% of mortality. Follow-up varied from 11 months to 9 years (average 4.5). The clinical and histopathological findings (identical with those reviewed in the literature) confirmed occurrence of two biologically different types of parosteal osteosarcoma: predominant type is originally "benign" but has a definite malignant potential, causing metastases after long symptom-free interval. The other type is highly malignant from the beginning. More radical surgery is recommended for the latter category of tumors, followed by chemotherapy. Compartmental, radical "en bloc" resection, followed by regular review of the patients, is recommended for the former (Tab. 1, Fig. 3, Ref. 20). Full Text (Free, PDF) www.bmj.sk.