Imaging tumors of the patella

Giant Cell Tumor of the Patella: A Case Report

Giant cell tumors (GCT) are uncommon as primary tumors localized within the patella. This is a case report of a 25-year-old male who developed a GCT in his patella. The patient had intermittent right anterior knee discomfort for a year before presentation. The radiological features pointed to a benign illness. The GCT of the bone was the intraoperative pathological diagnosis. Radiation curettage and adjuvant therapy consisting of phenol and ethanol injections and calcium phosphate cement were used to treat the lesion. Histologically, the tumor comprised several large osteoclastic cells mixed in with spherical- or spindle-shaped mononuclear cells. Sixteen months following surgery, the patient had no symptoms and no signs of distant metastasis or local recurrence. In particular, in young individuals, patellar GCTs may be included in the differential diagnosis of anterior knee discomfort and/or edema despite their rarity.

Oesophageal carcinoma with solitary patellar metastasis: a rare case report

The incidence of tumours found in the patella, including primary and metastatic tumours, is low. Solitary metastasis of oesophageal carcinoma (OC) in the patella is even rarer. A 50-year-old man presented to our clinic because of pain and limited range of motion in the right knee for 4 hours and after a fall. On the basis of the patient’s medical history, he was diagnosed with OC 2 months previously and underwent two cycles of paclitaxel liposome combined with tiggio chemotherapy (oral tiggio, 40 mg, two times/day, with a treatment cycle of 3 weeks). A 99mTc-methylene diphosphonate bone scintigraphy scan showed increased radioactivity in the right patella. A right knee biopsy showed the presence of patellar metastasis from OC. Unfortunately, the patient denied additional treatment and was discharged for personal reasons. At the 1-month follow-up, which was conducted by a telephone survey, we learned that the patient had died of acute pulmonary embolism. X-rays and computed tomography are useful for diagnosing patellar metastases, but 99mTc-methylene diphosphonate bone scintigraphy can help physicians diagnose patellar metastasis of OC more rapidly. Biopsy with pathology is the gold standard for diagnosing patellar metastases. Additionally, timely surgical treatment prolongs the survival time of these patients.

Chondroblastoma of the patella with secondary aneurysmal bone cyst, an easily misdiagnosed bone tumor:a case report with literature review

Background

Chondroblastoma (CB) is a rare, primary, benign bone tumor that commonly affects men aged 15–20 years. It is usually detected in the epiphysis of the long bones, such as the proximal femur, humerus, and tibia. The patella is an infrequent site. CB with secondary aneurysmal bone cyst (ABC) is extremely rare in the patella, which can be easily confused with other common bone tumors of the patella. Thus, it is necessary to make the right diagnosis to get a good outcome.

Case presentation

We have presented here the case of a 30-year-old man who was suffering from anterior knee pain for the past 6 months that had aggravated 2 weeks before the presentation. Osteolytic bone destruction in the patella could be detected in both his X-ray and computed tomography (CT) examinations, while the magnetic resonance imaging (MRI) detected a fluid level. Accordingly, secondary ABC was presumed. We diagnosed the condition as giant cell tumor (GCT) with secondary ABC and, accordingly, performed curettage inside the focus region with autogenous bone grafting following the patient’s medical history, physical manifestations, results of physical and ancillary examinations, and the disease characteristics. However, the intraoperative and postoperative outcomes indicated that the patient’s histopathology was consistent with that of typical CB, suggesting a definitive error in diagnosis. Accordingly, the patient was finally diagnosed with patella CB along with secondary ABC.

Conclusions

Past studies have demonstrated that the 3 commonest bone tumors affecting the patella are GCT, CB, and ABC. CB with secondary ABC can be easily misdiagnosed as GCT with secondary ABC or ABC. Performing incision biopsy or excision biopsy and conducting histological examination may be the most effective method for suspected CB with secondary ABC.

Intra-osseous tophaceous gout of a bipartite patella mimicking aggressive bone tumour

This is a very rare case of gouty tophus in the patella of a 31-year-old male, without any medical co-morbidities. The patient initially presented after an injury to left knee but came back months later due to persistence of pain. Surgical decision was made based on imaging findings in computed tomography and magnetic resonance imaging of an intraosseous lesion that has increased in size. The initial diagnosis is that of an aggressive bone tumour. The diagnosis of an intraosseous gout was made intra-operatively upon seeing the characteristics of the lesion, and upon confirmation of the biopsy results. Gout can usually be managed medically with urate lowering drugs and lifestyle change. However, when presented with a tophus that is increasing in size and causing mass effect on the involved bone, surgical management is indicated.

Hemangioma in the patella - A case report

Hemangioma in the patella is rare, and the osteolytic finding mimics a solid tumor. In the current report, a 69-year-old male with hemangioma in the patella had pain in the anterior left knee when kneeling. The osteolysis was not obvious on plain radiographs in the anteroposterior or lateral views, but was clear in the axial view, as well as with computed tomography. Bone scintigraphy showed uptake of technetium. Magnetic resonance imaging suggested a cystic lesion, but a primary solid tumor with cystic changes could not be ruled out. After confirmation of the diagnosis by biopsy, curettage and beta-tricalcium phosphate grafting was performed. Preoperative symptoms disappeared 6 months after the operation. It is easy to miss these lesions on plain radiographs. Even after identification of the lesion, a solid tumor with a destructive nature would have been suspected because of the uptake on bone scintigraphy. In a previous report, patellectomy was performed, but curettage may be sufficient for a benign tumor, as in the current case.

Patellar Osteoid Osteoma as a Cause of Intractable Anterior Knee Pain - A Case Report and Systematic Review of Literature

INTRODUCTION

Patellar involvement by osteoid osteoma is very rare. Osteoid osteomas that present as anterior knee pain are frequently misdiagnosed which leads to initial delay in treatment. Plain radiology has poor diagnostic yield. A combination of high index of suspicion, appropriate imaging, and complete ablation of the lesion is necessary to achieve good outcomes.

CASE REPORT

A 16-year-old male presented with insidious onset anterior knee pain for the past 2 years. The pain was intermittent and mild; however, it increased progressively in intensity and frequency, which was worse at night. Examination reveals minimal effusion in the suprapatellar pouch, full range of motion of the knee, and wasting of the quadriceps. Serum biochemistry parameters were in normal limits. Plain radiographs did not reveal any significant abnormality. On magnetic resonance imaging, a hypointense, punctate lesion surrounded by a small hyperintense zone was noted at medial aspect of patella. A computed tomography scan showed the lesion with a central nidus, surrounded by a sclerotic rim, confirming the diagnosis of osteoid osteoma. Radiofrequency ablation was carried out without any post-procedural complications. The patient was pain free a few days after the procedure. At 14-month follow-up, there was no recurrence of symptoms.

CONCLUSION

Osteoid osteomas that present as anterior knee pain are frequently misdiagnosed. Plain radiology has poor diagnostic yield. A combination of high index of suspicion, appropriate imaging, and complete ablation of the lesion is necessary to achieve good outcomes.

Chondroblastoma of the patella with pathological fracture in an adolescent: a case report

BACKGROUND

Chondroblastoma is a rare primary bone tumor of young people that generally occurs in the epiphyseal plate of long bones. To date, only 13 cases of patella with pathological fracture in chondroblastoma have been previously published.

CASE PRESENTATION

A 15-year-old male patient presented with acute pain in the left knee after an injury occurred while playing basketball. Plain radiographs and computed tomography showed a pathological fracture of the left patella with an osteolytic lesion (1.5 × 2 × 3 cm). Magnetic resonance imaging revealed an expansile lesion within the patella with a slightly high signal on the T1-weighted image, a high signal on the T2-weighted image and soft tissue swelling in front of the patella. A ^m99Tc bone scintigraphy revealed moderate uptake. The preoperative diagnosis was chondroblastoma. This patient underwent intralesional meticulous extended curettage, adjuvant high-speed burr, 95% alcohol and electrotome treatment, autogenous iliac crest bone grafting, and internal fixation. A postoperative pathological diagnosis was chondroblastoma. The patient's function was satisfactory, and there was no sign of tumor recurrence. The internal fixator was good, with no loosening or migration observed at the last follow-up at 20 months after surgery.

CONCLUSIONS

Rarely, chondroblastoma of the patella can present with acute pain due to pathological fracture. We present the 14th such case in the literature to associate patellar chondroblastoma with pathological fracture. The patient was treated with curettage, inactivation, autogenous bone grafting, and internal fixation. A satisfactory therapeutic effect was obtained. This case may be beneficial to the diagnosis and treatment of chondroblastoma patella.

Giant cell tumour of the patella with local recurrence: successful management with excision, curettage and artificial bone grafting

Primary patellar neoplasms are rare, comprising 0.12% of primary bone tumours; thus, no standardised treatment related to staging exists. 70%-90% of primary patellar neoplasms are benign or intermediate with giant cell tumour (GCT) being the most common. GCTs are locally aggressive, have a high recurrence rate and metastasise in 1%-2%. We report the case of a 23-year-old man with histologically confirmed recurrent GCT of the patella to demonstrate that aggressive surgical management options described in the literature, such as patellectomy with or without complex reconstruction, may be excessive and cause patients undue morbidity. Initially, the patient underwent intralesional curettage with excellent recovery, but presented again with a local recurrence within a year. A further definitive operation was performed which included excision of the inferior pole followed by curettage of the patellar body and artificial bone grafting. The patient made a good recovery and at 5-year follow-up has maintained good function.

Chondrosarcoma of the patella: A case report

RATIONALE

Chondrosarcoma, characterized by the production of cartilage matrix, is a common bone tumor, accounting for 20% to 27% of all malignant bone tumors. It often occurs in the cartilage of the pelvis, femur, tibia, and humerus. However, chondrosarcoma of the patella is extremely rare.

PATIENT CONCERNS

The present study describes a case of chondrosarcoma affecting the right patella in a 68-year-old woman. The chief complaints were painful swelling and limitation of motion of the right knee for about half a year. The pain was a kind of dull ache. The skin around the right knee was red and hot. Moreover, she had a claudication gait due to the symptoms.

DIAGNOSES

Irregular lytic lesions with ill-defined margins in the patella were determined through computed tomography and magnetic resonance imaging. The diagnosis of primary grade II chondrosarcoma was finally confirmed on the basis of postoperative pathological examination.

INTERVENTIONS

The patient underwent an open surgery named extensive resection of patellar tumor to remove the tumor tissue completely.

OUTCOMES

The patient was discharged without any complications 1 week after the surgery. At the 3-month follow-up, the patient was completely free from pain during daily activities, and normal range of motion of the right knee was achieved. Her gait was normal. There was no evidence of recurrence.

LESSONS

We believe that an extensive resection is suitable for treating chondrosarcoma to avoid as far as possible local recurrence. An awareness of the potential for chondrosarcoma to present in the patella is crucial for both orthopedic surgeons and radiologists when confronted with similar cases. Besides, as reports of chondrosarcoma of the patella are rare, this study adds a better understanding of this rare condition to the medical literature.

Giant cell tumor of the patella with a secondary aneurysmal bone cyst: A case report

The substance of the patella is an uncommon location for tumor occurrence and development. The present study reports a case of giant cell tumor (GCT) of the patella, combined with an aneurysmal bone cyst (ABC). To the best of our knowledge, this is the second report of GCT with ABC published in English. GCT is the most common type of benign tumor. Secondary ABC is frequently associated with GCT, but this symbiotic tumor rarely occurs in the patella. A 27-year-old male patient was examined at the outpatient clinic, and clinicopathological characteristics of the tumor were observed. X-ray and computed tomography (CT) scans revealed a lytic lesion located in the center of the right patella. Curettage, followed by autogenic and allograft bone grafting, was performed. Histopathologically, the lesion was diagnosed as a GCT with secondary ABC. No recurrence or metastasis was identified during the 1-year follow-up period. The present study reports a case of GCT with secondary ABC, and discusses the rare location and histopathological type of this tumor, in order to improve diagnosis and treatment of patellar tumors in general.

Primary tumors of the patella

The patella is an uncommon location for cancerous occurrence and development. The majority of tumors of the patella are benign, with a significant incidence of giant cell tumors and chondroblastoma. With the development of modern diagnostic technologies, there appear however many other histological types which raise challenges of diagnosis and treatment. In this article, we review the reported histological types of primary patellar tumors. Specifically, epidemiology, symptomatology, imageology, histopathology, and treatment options for these histological lesions will be discussed, respectively. As there is an increasing focus on the diagnosis and the treatment of these lesions, the availability of the integrated information about primary patellar tumors becomes more significant.

Giant cell tumor of the patella: An uncommon cause of anterior knee pain

The patella is a rare site for the development of primary tumors. This is the case report of a giant cell tumor (GCT) occurring in the patella in a 25-year-old woman. The patient presented with a 1-year history of occasional right anterior knee pain. The radiological characteristics suggested a benign condition. The intraoperative pathological diagnosis was GCT of the bone. The lesion was treated by radical curettage with adjuvant therapy comprising phenol and ethanol and injection of calcium phosphate cement. Histologically, the tumor consisted of round or spindle-shaped mononuclear cells admixed with numerous osteoclastic giant cells. The patient was asymptomatic and there was no evidence of local recurrence or distant metastasis 16 months after surgery. Although rare, patellar GCT may be included in the differential diagnosis of anterior knee pain and/or swelling, particularly in young adults.

Chondroblastoma of the patella with aneurysmal bone cyst

Chondroblastoma of the patella is rare. Aneurysmal bone cysts, which develop from a prior lesion such as a chondroblastoma, are seldom seen in the patella. The authors report a case of a 36-year-old man who presented with 2 years of right knee pain without calor, erythema, pain on palpation, or abnormal range of motion. Radiological studies suggested aneurysmal bone cyst. The lesion was excised with curettage and the residual cavity filled with autogenous bone graft. Histopathology revealed chondroblastoma associated with a secondary aneurysmal bone cyst. In the follow-up period, the patient demonstrated normal joint activities with no pain. Normal configuration of the patella and bone union were shown on plain radiographs. The authors present a review of the literature of all cases of patellar chondroblastoma with aneurysmal bone cyst. This case is the 14th report of aneurysmal bone cyst arising in a chondroblastoma of the patella. According to the literature, computed tomography and magnetic resonance imaging are useful in the study of these lesions. The pathologic diagnosis is based on the presence of chondroblastoma and aneurysmal bone cyst. Treatment of this lesion includes patellectomy, curettage alone, and curettage with bone grafting. Despite the risk of recurrence of this lesion in the patella, the authors first recommend curettage followed by filling the cavity with bone graft. To protect the anterior tension of the patella intraoperatively, the bone window should be made at the medial edge of the patella to perform the curettage and bone grafting.

Secondary aneurysmal bone cyst following chondroblastoma of the patella

Aneurysmal bone cyst (ABC) is a rare benign cystic lesion of the bone that composes 1-2% of the entire bone tumors. Some are idiopathic, and some occur secondary to other tumors such as giant cell tumor and chondroblastoma. In this article, we report the clinical, radiographic, and histological findings of a secondary ABC following chondroblastoma of the patella with a review of the literature.