Periosteal chondroma. A review of twenty cases

Surgical Resection of Nasal Chondroma via open Rhinoplasty Approach: A rare case Presentation and Review of Literature

Chondromas are benign tumors composed of mature hyaline cartilage tissue with well-defined boundaries that are commonly localised in the extremities with very few cases described in the head and neck region. We present a case of 57-year-old patient who consulted a specialist for an examination due to a change in the tip of the nose that persisted for the past 2 years. The clinical exam revealed a firm, tumor-altered tip of the nasal pyramid, with hyperemia of the skin above the mass. Biopsy was taken under local anesthesia; the histopathology analysis indicated a mesenchymal tumor producing the chondroid matrix suggestive of nasal type chondroma. Computerized tomography showed an ovoid, moderately inhomogeneous, sharply limited formation measuring 21 × 18 × 24 mm present mediosagitally at the top of the nasal pyramid. After preoperative preparation, the surgery was performed by open rhinoplasty approach. Tumor was completely excised with reconstruction of nasal septum and alar cartilage.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12070-023-03661-0.

Chondroma Arising from the Temporomandibular Joint: A Case Report

Periarticular chondromas are common in the humerus and femur but rarely occur in the temporomandibular joint. We report a case of a chondroma in the anterior part of the ear. One year prior to his visit, a 53-year-old man became aware of swelling in the right cheek region which gradually increased in size. In the anterior part of the right ear, there was a palpable 25 mm tumor, elastic and hard, with poor mobility and without tenderness. A contrast-enhanced computed tomography CT showed a mass lesion with diffuse calcification or ossification in the upper pole of the parotid gland and areas of poor contrast within. A magnetic resonance imaging showed a low-signal mass lesion at the parotid gland with some high signals in both T1 and T2. Fine-needle aspiration cytology did not lead to diagnosis. Using a nerve monitoring system, the tumor was resected with normal tissue of the upper pole of the parotid gland in the same way as for a benign parotid tumor. Distinguishing between pleomorphic adenoma, including diffuse microcalcification of the parotid gland and cartilaginous tumors of the temporomandibular joint, may be sometimes difficult. In such cases, surgical resection may be a beneficial treatment option.

Peering beneath the surface: Juxtacortical tumors of bone (part I)

Juxtacortical or surface tumors of bone are neoplasms arising from or just outside the cortex, and are composed of different histologic types. Although the imaging appearances of these lesions have similarities to their intramedullary counterparts, their location alters their radiographic and MR characteristics, creating difficulties in diagnosis. Meanwhile, several non-neoplastic lesions, such as stress reaction/stress fracture and indolent infectious processes, compound the differential diagnosis. Neoplastic juxtacortical lesions of bone have been classified into five categories: cartilaginous, fibrous, lipomatous, osseous, and metastatic tumors. Our goal in part one of this review is to illustrate the characteristic radiographic, CT and MR imaging features of various juxtacortical neoplasms, including pathognomonic imaging findings that can aid in diagnosis, and to develop an appropriate differential diagnosis for surface lesions based on imaging characteristics, lesion location and patient age.

Periosteal chondroma of the cuboid with secondary aneurysmal bone cyst in a setting of secondary hyperparathyroidism

We report the case of a 35-year-old woman with painful, nontender mass at the right lateral hindfoot. Computed tomography (CT) and magnetic resonance imaging (MRI) indicated the suspect of a chondroid tumour in the cuboid. The tumour was resected en bloc and histology revealed the presence of a periosteal (juxtacortical) chondroma with secondary aneurysmal bone cyst. Secondary hyperparathyroidism was detected in laboratory tests and put into context with the histopathologic findings. In conclusion, a rare case of periosteal chondroma of the cuboid with secondary aneurysmal bone cyst in a setting of secondary hyperparathyroidism due to vitamin D deficiency is presented.

LEVEL OF CLINICAL EVIDENCE

4.

Juxtacortical Chondroma of the Hand: Treatment by Resection of the Tumour and the Adjacent Bone Cortex

A recurrence of a juxtacortical chondroma of the finger after marginal excision prompted us to review the treatment of this condition. Although the recommended treatment is simple curettage or marginal excision, the reported recurrence rate is significantly higher for lesions in the hand than those in other locations and recurrences only occurred in patients who had local treatments which did not include excision of the adjacent bone cortex.

We report five patients with juxtacortical chondroma of the fingers. The first patient underwent marginal excision without resection of the underlying bone cortex. The other four patients underwent intralesional, marginal or wide excisions of tumour with resection of the bone cortex underlying the lesion. Recurrence was only seen in the patient who did not undergo resection of the bone cortex. Resection of the underlying bone cortex after excision of this tumour may be advisable for the treatment of this tumour in the hand to reduce the rate of recurrence.

Periosteal chondroma of the femur: A case report and review of the literature

Periosteal chondroma is a rare benign cartilage tumor located on the cortical bone, which may be mistaken clinically and histologically for other and more common tumors in this location. The current study reports the case of periosteal chondroma located in the distal femur of a 14-year-old female. A non-tender swelling, 5×4 cm in diameter, was identified on computed tomography, a radiological study of which revealed an overhanging edge and a radiolucent shadow with stippled calcification in radiographs and a lobular heterogeneous mass in magnetic resonance imaging. Cytological examination of the excision biopsy revealed cellular pleomorphism and binucleate cells. The patient underwent en bloc resection of the tumor and covering periosteum, and the histological diagnosis was subsequently determined to be periosteal chondroma. The present study also reviews nine previously reported cases of periosteal chondroma in the femur, with a discussion of the demographic characteristics, imaging features, differential diagnosis and treatment of bone tumors in this location. This study aims to inform clincians that periosteal chondromas may occur in the distal femur although osteochondromas are more common and to discuss making a differential diagnosis between periosteal chondroma and other bone tumors.

A giant periosteal chondroma of the distal femur successfully reconstructed with synthetic bone grafts and a bioresorbable plate: a case report

Periosteal chondromas are rare benign cartilaginous tumors that arise adjacent to the cortex beneath the periosteum. These lesions are usually slow-growing and rarely exceed 3 cm in the greatest dimension. Here, we describe a 17-year-old boy who had a giant periosteal chondroma of the right distal femur, which was treated with intralesional resection and intensive curettage. In addition, we report a novel application of a bioresorbable plate in the management of the large bone defect after resection of a benign bone tumor.

Incidence of nonunion after isolated arthroscopic ankle arthrodesis

PURPOSE

To determine the incidence of nonunion after isolated arthroscopic ankle arthrodesis.

METHODS

Electronic databases and relevant peer-reviewed sources, including OvidSP/Medline (http://ovidsp.tx.ovid.com) and Google, were systematically searched for the terms "arthroscopic ankle arthrodesis" AND "nonunion". Additionally, we manually searched common American, British, and European orthopaedic and podiatric scientific literature for relevant articles. Studies were eligible for inclusion only if they included the following: isolated ankle arthrodesis, greater than 20 ankles, minimum mean follow-up of 12-months, a 2-portal anterior arthroscopic approach, fixation with 2 or 3 large-diameter cannulated cancellous screws, and the nonunion rate with no restriction on cause.

RESULTS

After considering all the potentially eligible articles, 7 (25.9%) met the inclusion criteria. A total of 244 patients (244 ankles)-148 (60.7%) male and 96 (39.3%) female patients, with a weighted mean age of 49.2 years-were included. For those studies that specified the exact follow-up, the weighted mean was 24.1 months. A total of 21 nonunions (8.6%) were reported, with 14 (66.7%) being symptomatic and requiring further intervention.

CONCLUSIONS

The results of this systematic review reveal an acceptable incidence of nonunion of 8.6%. However it is important to recognize that of these nonunions, 66.7% were symptomatic. This supports the belief that regardless of approach, nonunion of an ankle arthrodesis is problematic. In light of this finding, additional prospective studies are warranted to compare directly the incidence of nonunion between open, minimum incision, and arthroscopic approaches with a variety of fixation constructs.

LEVEL OF EVIDENCE

Level IV, systematic review of level IV studies.

Chondroma of the vertical ramus of the feline mandible

A 5-year-old, castrated male, domestic shorthair cat presented with firm swelling in the right temporal region of the skull. The cat's jaws were almost locked in the closed position. Radiographs showed a mass with an irregular mineralized matrix superimposed on the caudal right mandible and temporomandibular joint. Surgical exploration revealed that the mass arose from the proximal part of the vertical ramus, which was removed, with the exclusion of the temporomandibular joint. It was possible to open the cat's mouth to nearly normal extension immediately after surgery. Recovery was uneventful - the cat has had no problem eating and no mass recurrence has been detected 3 years after surgery. Histological examination of the mass was consistent with chondroma. To the best of our knowledge, this is the first clinical and pathological description of a chondroma in cats, and one of the rare cases describing clinical presentation and management of primary bone tumours involving the vertical ramus of the feline mandible.

Chondrosarcomas revisited

Chondrosarcomas are malignant bone tumors with pure hyaline cartilage differentiation; myxoid changes, calcification, or ossification may be present. Several subtypes of chondrosarcomas exist. Behavior patterns vary, ranging from slow-growing nonmetastasizing lesions to aggressive metastasizing sarcomas. Symptoms are usually mild, with duration ranging from several months to years, and usually consist of persistent, dull, aching pain or palpable masses. Radiographic findings include bone expansion with cortical thickening, radiolucent areas with variably distributed punctate or ring-like matrix calcifications, cortical erosion or destruction, endosteal scalloping, and scant or absent periosteal reaction; extension into the soft tissue may be present. Histological differential diagnosis from benign cartilaginous lesions can be achieved by increased cellularity, enlarged plump nuclei, binucleated cells, hyperchromatic nuclear pleomorphism, and permeation of cortical or medullary bone. Atypia is usually mild to moderate; necrosis and mitoses can be seen, particularly in high-grade lesions. Adequate surgery is the mainstay of treatment. High-grade and pelvic chondrosarcomas are best managed with wide resection. Because of the low metastatic potential and low local recurrence rate noted with intralesional surgery, low-grade chondrosarcomas can be treated with curettage (with or without treatment of the defect cavity) with a local adjuvant, such as phenol or cryotherapy. Adjuvant chemotherapy may be considered for mesenchymal and dedifferentiated chondrosarcomas. Radiation therapy can be considered after incomplete resection or if resection is not feasible or would cause unacceptable morbidity.

The geometric osteotomy: joint preservation in juxta-articular surface bone neoplasms

Purpose. To present the oncologic and functional results of a consecutive series of patients treated by geometric osteotomy and allograft reconstruction for juxta-articular surface bone neoplasms.

Patients. Twelve consecutive patients (mean age 28 years) underwent excision of benign aggressive or malignant juxta-articular surface bone neoplasms. In each case, only part of the circumference of the bone was excised, and the joint surface was preserved and kept in continuity with the remainder of the bone. The defects were filled with allograft or autograff, and internally fixed as appropriate.

Methods. Patients were eligible for the study if they had a histologically proven, primary tumour of bone adjacent to a joint such that the turnout could be completely excised with a partial cortical resection and preservation of the joint. The database at the University Musculoskeletal Oncology Unit was used to identify all cases. Patient demographics and oncologic results were recorded. Functional assessment was performed using the Musculoskeletal Tumor Society rating scale and the Toronto Extremity Salvage Score.

Results. Nine tumours were about the knee and three were in the proximal humerus. Negative margins were achieved in all cases. No patient had metastatic disease at a mean follow-up of 56.5 months. There was one local recurrence and this was managed by conversion to a Van Nes rotationplasty. Functional results were excellent in the proximal humeral cases and in cases about the knee where the stabilizing ligaments were preserved. Cases with post-operative knee instability were less successful but none the less were well controlled with bracing.

Discussion. This technique offers an alternative to joint excision and prosthetic replacement in a group of young patients.

An approach to the failed ankle arthrodesis

Ankle arthrodesis remains the gold standard of surgical treatment for advanced ankle joint arthritis. Failure can occur as a result of infection, nonunion or malunion, resulting in pain and poor function. This paper offers a systematic approach to preventing, and managing these problems should they occur. Revision arthrodesis performed with a detailed understanding of the appropriate alignment and mechanics of the ankle joint, combined with meticulous attention to understanding and reversing the cause of the failure can result in successful salvage and restoration of function.

Periosteal chondroma at birth

Periosteal chondroma is a slow-growing, cartilaginous, surface tumor that usually occurs in the second and third decades of life. The youngest reported age at diagnosis is 5 years. Marginal excision is the treatment of choice. We report a case of a periosteal chondroma noted at birth and treated conservatively. This report expands the age range of periosteal chondroma to include neonates and suggests a role for observation in its management.

Lesions of the Bones of the Hands and Feet: A Study of 50 Cases

Context.—The bones of the hands and feet constitute more than half of the bones in the human skeleton (106/ 206), but lesions occurring in them are infrequently reported. Although many of the lesions that occur in the rest of the skeletal bones can occur in bones of the hands or feet, their distribution and frequency differ.

Objective.—To study lesions involving bones of the hands or feet.

Design.—Retrospective study of all lesions involving bones of the hands or feet during the period from January 2000 to September 2006 from a university hospital in southern India. Clinical, radiologic, and pathologic features were reviewed.

Results.—The 50 lesions encountered included 23 (46.0%) infections/inflammatory lesions, 16 (32.0%) benign tumors, 6 (12.0%) malignant tumors, and 5 (10.0%) tumorlike lesions. Giant cell tumor was the most common benign tumor. Malignant tumors involved the nonphalangeal bones, with chondrosarcoma the most common.

Conclusions.—Lesions of the bones of the hands or feet are uncommon. Awareness and correlation of clinical, radiologic, and pathologic features help in making correct diagnoses.

Hyoid chondroma presenting as an external neck mass

Chondromas of the larynx are rare neoplasms; only a few examples of cartilaginous tumors affecting hyoid bone have been reported. A 33-year-old woman presented with a neck mass on the left carotid triangle. The patient's computed tomography and magnetic resonance imaging revealed a heterogenous mass, which seemed to originate from the left greater cornu of hyoid. The mass was excised using a transcervical approach with left greater cornu of hyoid bone. The pathologic diagnosis was chondroma of hyoid. Expert radiologic and pathologic review is mandatory in cartilaginous neoplasms of the larynx. Cartilaginous neoplasms of the hyoid should be included in the differential diagnosis of neck masses at the carotid triangle.

Periosteal osteoblastoma: report of a case with a rare histopathologic presentation and review of the literature

Osteoblastoma is an uncommon benign bone tumor most commonly located in the vertebral column or metaphysis of a long bone. Periosteal location is rare. We report a periosteal-based osteoblastoma, arising from the proximal tibia, in a 20-year-old woman who presented with knee swelling and pain of 2-year duration. Imaging studies showed a metaphyseal surface-based lesion with patchy radiodensities. The cortico-medullary junction was intact. The lesion was totally excised. Histopathologic evaluation disclosed immature bone and osteoid deposition in a vascularized stroma, associated with numerous osteoblasts and osteoclasts rimming the bony trabeculae. Plate-like arrangements of cartilage in the margin of the neoplastic tissue were also identified. At 16 months postoperatively, the patient was well without recurrence. Although extremely unusual, the presence of cartilage does not necessarily exclude the diagnosis of osteoblastoma.

Intra-articular chondroma of the knee

Chondromas are tumours that develop in relation to the periosteum and, although they are common around the knee, most reports deal with soft tissue chondromas in para-articular locations or intracortical tumours in extra-articular regions. We report a rare case of an intra-articular chondroma in a 16-year-old boy of Asian origin developing in the region of the medial femoral condyle of the femur and extending into the femoral sulcus and the patellofemoral joint.

Surface lesions of the bones of the hand

Surface lesions involving the bones of the hand are uncommon. This pictorial review illustrates the spectrum of conditions including benign primary bone tumours, malignant primary bone tumours and non-neoplastic disorders. The review focuses on the radiographic appearances of these lesions and other techniques such as CT and MR imaging that may suggest a specific diagnosis.

The medial malleolar approach for arthrodesis of the ankle: a report of 13 cases

A series of thirteen patients that had primary fusion of the ankle joint through an isolated medial approach is presented. The technique involves transection of the medial malleolus for access to the articular surfaces, rather than the traditional transfibular approach. The medial malleolus was replaced in all cases, preserving the deltoid ligament. Union was achieved in 12 of 13 patients. The technique is described in detail and the advantages of this approach are discussed with respect to preservation of the blood supply to the talus and tibia.

Tenosynovial (extraarticular) chondromatosis: an analysis of 37 cases of an underrecognized clinicopathologic entity with a strong predilection for the hands and feet and a high local recurrence rate

Tenosynovial chondromatosis is a multinodular cartilaginous proliferation that arises from the tenosynovial membranes. This report describes the clinical, radiologic, and histopathologic findings in 37 cases of this uncommon entity. There were 17 males and 20 females, ranging in age from 20 to 86 years (mean and median age, 46 years). The process involved tenosynovium of the fingers (n = 19), feet (n = 8), wrists (n = 4), ankles (n = 2), hand, not otherwise specified, or palm (n = 2), knee (n = 1), and forearm (n = 1). Signs of disease or symptoms were present for 5 weeks to 18 years (median duration, approximately 2 years) before surgical excision. The two most common complaints were a painless mass and a mass that was mildly tender with pressure. None of the tumors had clinical, radiologic, or histopathologic evidence of articular or bone involvement. Histologically, all tumors consisted of a multinodular cartilaginous proliferation involving tenosynovium and/or subsynovial connective tissue. Mild or moderate atypia, as encountered in chondroma of soft parts and synovial chondromatosis, was a frequent finding. Follow-up information was available for 16 patients (43%). Only two patients with follow-up information remained disease free after their initial surgical procedure. Seven patients had one recurrence and seven patients had two or more recurrences. Tenosynovial chondromatosis appears to be an extraarticular counterpart of synovial (intraarticular) chondromatosis. Our review indicates this process is often confused with chondroma of soft parts, in part, because both entities have a predilection for the hands and feet. Diagnosis of this underrecognized entity is of clinical importance because of the high local recurrence rate.

Periosteal chondroid tumors: radiologic evaluation with pathologic correlation

OBJECTIVE

The purpose of this study was to determine whether the imaging features of periosteal chondroid tumors correlate with histopathology.

MATERIALS AND METHODS

Twenty-two patients (nine women and 13 men; mean age, 33 years) with pathologically proven periosteal chondroid lesions were retrospectively reviewed. The imaging modalities included conventional radiography (n = 17), CT (n = 10), and MR imaging (n = 14). The images were reviewed by two osteoradiologists, with agreement by consensus. Evaluation criteria included lesion location, mineralization, and size; periosteal reaction; and cortical response. Intramedullary extension, adjacent intramedullary edema, soft-tissue edema, and intrinsic characteristics were also evaluated on MR imaging. After the evaluation, a radiologic diagnosis of chondroma or chondrosarcoma was obtained. An experienced osteopathologist who was unaware of the patient's medical history and radiologic findings reviewed all histopathology. Agreement between the radiologic and the histopathologic diagnosis was tested using the kappa analysis. Imaging features were correlated with the pathologic findings, and a statistical analysis was performed.

RESULTS

Using strict pathologic criteria, we diagnosed 11 chondromas and 11 chondrosarcomas (nine, grade I; two, grade II). Moderate agreement was reached between the radiologic and the pathologic diagnosis (kappa = 0.55). The size of periosteal chondrosarcomas (range, 3-14 cm; median, 4 cm) was considerably larger than the size of the chondromas (range, 1-6.5 cm; median, 2.5 cm; p < 0.05). Other imaging features did not significantly correlate with benign versus malignant disease at pathology (all p > 0.05).

CONCLUSION

A variable overlap existed in the imaging appearances of benign and malignant periosteal chondroid lesions, with size being the most reliable indicator in distinguishing the two lesions. This and the fact that histologic differentiation of the entities can be difficult, suggests that surgical wide excision may be the most appropriate procedure in treating patients with lesions greater than 3 cm.

Periosteal Chondroma: MR Characteristics

PURPOSE

The purpose of this study was to describe the MR characteristics of periosteal chondroma.

METHOD

MR images of 12 proven cases of periosteal chondroma were analyzed with reference to tumor morphology and size. MR features were correlated with radiographic and pathologic findings.

RESULTS

Tumor size ranged from 1 to 7 cm in maximum diameter with a mean value of 2.6 cm. On MR images, a soft tissue mass at the bone surface with pressure erosion of adjacent cortical bone could be identified in all cases. All lesions were bordered by a hypointense rim (100%) and frequently showed a lobulated configuration (75%). Edema of medullary bone or soft tissues was not observed in any of the cases. Signal intensity of cartilaginous tumor tissue was typically hypo-or isointense relative to muscle on T1-weighted (100%) and hyperintense relative to fat on T2-weighted (92%) and T2*-weighted (100%) MR images. Radiographically significant calcifications of the tumor matrix, present in half of the cases, caused focal signal loss on MR images of all pulse sequences. Contrast enhancement was observed predominantly at the periphery of the lesions (100%), which on pathologic examinations typically contained fibrovascular bundles, surrounding the cartilage lobules.

CONCLUSION

Periosteal chondroma appears to have a relatively typical MR appearance, which reflects the histologic composition of the lesion. In addition to radiography, MRI therefore can substantially aid in the preoperative diagnosis of this rare bone lesion.

Periosteal chondroma of the distal radius

We report a case of periosteal chondroma in an unusual location at the distal end of the radius.

Non-tuberculous mycobacterial tenosynovitis: a review

The clinical characteristics, outcome and treatment of non-tuberculous mycobacterial tenosynovitis are reviewed. From lesions localized in the hand, 10 different species of non-tuberculous mycobacteria have been reported. The most common are Mycobacterium marinum and Mycobacterium kansasii. Other less frequent organisms are Mycobacterium avium complex, Mycobacterium szulgai, Mycobacterium terrae, Mycobacterium fortuitum, Mycobacterium chelonae, Mycobacterium abscessus, Mycobacterium malmoense and Mycobacterium xenopi. The infections appear to be the result of previous trauma, surgical procedure, corticosteroid injection or non-apparent inoculation (water contamination). Immunosuppression is sometimes associated with the infections and can be considered as a risk factor. Surgical debridement and appropriate mycobacterial cultures are critical to enable diagnosis and appropriate management. Specimens should be inoculated on a range of media and incubated at a range of temperatures in order to isolate mycobacteria with different growth characteristics (with prolonged incubation). The optimal treatment of these infections is discussed.

Periosteal chondroma developing in a rib at the side of a chest wall wound from a previous thoracotomy: report of a case

We describe herein the case of a 45-year-old man who developed a periosteal chondroma in a rib at the site of a thoracotomy that had been performed 24 years previously. To our knowledge, this is only the third case of a periosteal chondroma in a rib to be documented in the world literature. Some authors have suggested that trauma, including that of surgery, may induce chondroma formation and this association could have been an important contributing factor in the induction of the tumor in this patient.

Technique and clinical evaluation of arthroscopic ankle arthrodesis

Arthroscopic ankle arthrodesis has recently been shown to be an effective procedure with significant advantages when properly indicated. We report on the results of arthroscopic ankle fusion in 16 patients with idiopathic or posttraumatic osteoarthritis and rheumatoid disease. We used standard ankle arthroscopic technique and simple noninvasive distraction with hanging weights. All 16 patients had a successful fusion at an average of 9.5 weeks postoperatively. Complications included 1 lateral cutaneous neuroma, and 1 patient who required removal of screws because of superficial pain. Postoperative evaluation showed complete resolution of pain in 14 of 16 patients and significant improvement in gait. Fourteen of 16 patients were completely satisfied with the result and cosmesis, and only 1 patient required shoe modification. These results substantiate previous reports that arthroscopic ankle arthrodesis is successful, and where indicated, has significant advantages over the open technique.

Lesions of juxtacortical origin (surface lesions of bone)

A large variety of tumor and tumor-like conditions have been shown to originate from the surface of bone (Table 1). Most surface lesions are associated with periosteal reaction. The periosteum is a multipotential membrane. Its cellular composition may give rise to a variety of both neoplasms and tumor-like conditions. To avoid misinterpretation, the orthopedist, radiologist, and pathologist should be familiar with the entire spectrum of surface lesions. A better understanding of the natural history and biological behavior at different lesional maturity stages and correlation of the history with the radiographic and pathological findings is essential to establish the correct diagnosis. A history of injury or blunt trauma is very important. A stress fracture may produce a periosteal reaction acd callus that can be difficult to distinguish from osteosarcoma. In this review article, the authors wish to describe and define each term by its anatomy and radiographic features while discussing the entire spectrum of surface lesions. All the illustrative cases in this review article have been proven histologically.

Case report 588: Intracortical chondroma of the left femur

A case of intracortical chondroma in the left femur in a 22-year-old man is presented. Proof was obtained by open biopsy. The issue of periosteal vs intracortical chondroma was discussed in depth, with emphasis on the radiographic appearances. The differential diagnosis of this benign intracortical lesion was also included. The histopathologic characteristics of this intracortical chondroma were described and a possible explanation for the unusual location of the cartilage lesion within the cortex was considered.

Two cases of periosteal chondroma

One of our 2 cases of periosteal chondroma of the tibia recurred three times before definitive cure, and required extensive radiographic and histologic evaluation to avoid overinterpreting the malignancy. Our experience confirms that marginal excision should be employed.

Staging of musculoskeletal neoplasms. Musculoskeletal Tumor Society

This review reports the natural evolution of benign and malignant lesions of connective tissue derivation that led to the staging system, the system for both benign and malignant lesions, its articulation with surgical treatment and early experience with its use.