Diagnosis of chondroid lipoma by fine-needle aspiration biopsy

Differential diagnosis of lipoma and atypical lipomatous tumor/well-differentiated liposarcoma by cytological analysis

BACKGROUND

Adipocytic tumors are the most common soft tissue tumors, with lipomas and atypical lipomatous tumor/well-differentiated liposarcomas (ALT/WDL), which comprise most cases. Preoperative differential diagnosis of lipoma or ALT/WDL can provide important information for decisions regarding treatment. We evaluated the cytological findings of 20 cases of lipoma and ALT/WDL.

METHODS

Fluorescence in situ hybridization (FISH) was performed on formalin-fixed paraffin-embedded specimens (FFPE) to examine mouse double minute 2 homolog (MDM2) amplification in all cases. Tissue samples were collected from the center of the surgical materials, stained with Pap, and evaluated for 12 cytological parameters by six cytotechnologists.

RESULTS

The findings regarding large atypical cells, multinucleated cells, and nuclear pleomorphism were highly concordant among the cytotechnologists and were associated with MDM2 amplification. Large atypical cells, considered a highly specific feature of ALT/WDL, were not observed in lipoma cases. However, the sensitivity of the large atypical cell findings was not high (67%); therefore, comprehensive evaluation of multinucleated cells and pleomorphism is crucial for predicting ALT/WDL diagnosis. FISH of MDM2 on Pap-stained specimens was performed in four cases. In two, the results were similar to those of MDM2 FISH performed on FFPE sections and were reproducible, whereas in the other two, the signal could not be evaluated because of the strong background coloration.

CONCLUSIONS

Cytology specimens may be useful for the preoperative diagnosis of adipocytic tumors, particularly if the FISH conditions for Pap-stained specimens and the detection accuracy of MDM2 amplification can be improved.

Chondroid lipoma: multimodality imaging in a 9-year-old female

Chondroid lipomas are rare, benign lipomatous tumors that occur most frequently in adults during the fourth decade of life. While a female predominance was observed in the initial series of 20 cases described in 1993, the subsequent 49 reported cases do not support a strong gender predilection. We report a case of a chondroid lipoma presenting in a 9-year-old female as a painless, enlarging, left gluteal mass. This is the second case to be reported in the first decade of life and the fourth pediatric case reported in the literature (age < 21). We review the imaging and pathology findings as well as present a comprehensive review of the current literature.

Characteristics of chondroid lipoma: A case report and literature review

RATIONALE

Chondroid lipoma (CL) is a rare benign tumor. No relevant epidemiological reports have been published on CL, and there is a lack of uniform diagnostic and treatment criteria for the tumor.

PATIENT CONCERNS

Here, we report a case of CL with a mass on the left buttock for 2 weeks, and further illuminate its diagnosis and treatment.

DIAGNOSIS

The diagnosis of CL was rendered according to the pathological indices.

INTERVENTIONS

The tumor was resected completely under spinal anesthesia.

OUTCOMES

The patient was followed-up for 6 months and showed no tumor recurrence or metastasis and there was resolution of the patient's lower-limb numbness and pain.

LESSONS

The case study presented here provides evidence that CL could be effectively diagnosed by using ultrasound, puncture or biopsy, and/or magnetic resonance imaging. Furthermore, the patient recovered without any complications after completely resecting the tumor.

Intramuscular chondroid lipoma: magnetic resonance imaging diagnosis by 'fat ring sign'

BACKGROUND

Chondroid lipoma is an extremely rare variant of benign lipomatous lesions that is composed of lipoblasts, mature fat, and chondroid matrix. Although benign lipomatous lesions are the most common soft tissue tumors and imaging findings are often pathognomonic, there have been few reports describing the imaging features of chondroid lipoma.

CASE REPORT

We present magnetic resonance imaging (MRI) findings of a pelvic intramuscular chondroid lipoma in a 59 year-old man and describe a "fat ring sign" that may be useful to diagnose this rare tumor radiologically.

CONCLUSION

Magnetic resonance imaging findings of a chondroid lipoma may be heterogenous according to the distribution of the fatty and chondroid tissue. However, in the presence of "fat ring sign," radiologists should consider a diagnosis of chondroid lipoma preoperatively.

Chondroid lipoma of the right thigh: Correlation of imaging findings and histopathology of an unusual benign lesion

Chondroid lipoma is a rare and unusual benign soft tissue lesion. Although there have been several reports of the imaging findings of chondroid lipoma, very few described the radiographic calcification or ossification in a chondroid lipoma. We present a case of chondroid lipoma with adipose tissue and ossified components on plain radiography and MRI images. Correlation of imaging findings and pathological examination is provided to confirm the diagnosis.

Extraskeletal myxoid chondrosarcoma: Diagnosis of a rare soft tissue tumor based on fine needle aspiration cytology

Extraskeletal myxoid chondrosarcoma (EMC) is a rare soft tissue sarcoma with limited literature available on its cytological features. We report here one such case where a diagnosis of EMC was made based on fine needle aspiration cytology (FNAC). A 51 year-old male presented to our FNAC clinic with a slowly growing mass in the left thigh, which was subjected to fine needle aspiration biopsy. Radiological images showed no involvement of the underlying bone. Magnetic resonance imaging was suggestive of a malignant neoplasm. The FNA smears showed cell fragments and cords of monotonous cells embedded in abundant myxoid stroma. A diagnosis of a myxoid sarcoma favoring an EMC was made in this patient. Subsequent excision of the mass for histopathological examination confirmed this diagnosis. EMC has distinctive cytological features that are helpful in confidently making a diagnosis in the appropriate clinical setting.

Ossifying chondroid lipoma

Chondroid lipoma is a rare variant of lipoma that pathologically can mimic liposarcoma or possibly other sarcomas. Variants of lipoma, including chondroid lipoma, may demonstrate radiological evidence of fat within the tumor, but often display heterogeneous features on imaging studies, making a clinical diagnosis difficult. A large collective experience with the imaging characteristics of chondroid lipoma is lacking due to the rarity of this tumor. We present a case of chondroid lipoma of the upper thigh in a 37-year-old woman who had regions of metaplastic bone formation within the tumor. Radiologically, the tumor presented as a large soft tissue mass with calcification and ossification. Although metaplastic bone formation in conventional lipoma is well described, it has been rarely reported to occur in chondroid lipoma and has not been pathologically documented or illustrated. The imaging findings and histopathology of this unusual tumor are presented, along with a review of the literature.

Benign fatty tumors: classification, clinical course, imaging appearance, and treatment

Lipoma is the most common soft-tissue tumor, with a wide spectrum of clinical presentations and imaging appearances. Several subtypes are described, ranging from lesions entirely composed of mature adipose tissue to tumors intimately associated with nonadipose tissue, to those composed of brown fat. The imaging appearance of these fatty masses is frequently sufficiently characteristic to allow a specific diagnosis. However, in other cases, although a specific diagnosis is not achievable, a meaningful limited differential diagnosis can be established. The purpose of this manuscript is to review the spectrum of benign fatty tumors highlighting the current classification system, clinical presentation and behavior, spectrum of imaging appearances, and treatment. The imaging review emphasizes computed tomography (CT) scanning and magnetic resonance (MR) imaging, differentiating radiologic features.

From the archives of the AFIP: benign musculoskeletal lipomatous lesions

Benign lipomatous lesions involving soft tissue are common musculoskeletal masses that are classified into nine distinct diagnoses: lipoma, lipomatosis, lipomatosis of nerve, lipoblastoma or lipoblastomatosis, angiolipoma, myolipoma of soft tissue, chondroid lipoma, spindle cell lipoma and pleomorphic lipoma, and hibernoma. Soft-tissue lipoma accounts for almost 50% of all soft-tissue tumors. Radiologic evaluation is diagnostic in up to 71% of cases. These lesions are identical to subcutaneous fat on computed tomographic (CT) and magnetic resonance (MR) images and may contain thin septa. Lipomatosis represents a diffuse overgrowth of mature fat affecting either subcutaneous tissue, muscle or nerve, and imaging is needed to evaluate lesion extent. Lipoblastoma is a tumor of immature fat occurring in young children, and imaging features may reveal a mixture of fat and nonadipose tissue. Angiolipoma, myolipoma, and chondroid lipoma are rare lipomatous lesions that are infrequently imaged. Spindle cell and pleomorphic lipoma appear as a subcutaneous lipomatous mass in the posterior neck or shoulder, with frequent nonadipose components. Hibernoma appears as a lipomatous mass with serpentine vascular elements. Benign lipomatous lesions affecting bone, joint, or tendon sheath include intraosseous lipoma, parosteal lipoma, liposclerosing myxofibrous tumor, discrete lipoma of joint or tendon sheath, and lipoma arborescens. Intraosseous and parosteal lipoma have a pathognomonic CT or MR appearance, with fat in the marrow space or on the bone surface, respectively. Liposclerosing myxofibrous tumor is a rare intermixed histologic lesion commonly located in the medullary canal of the intertrochanteric femur. Benign lipomatous lesions may occur focally in a joint or tendon sheath or with diffuse villonodular proliferation in the synovium (lipoma arborescens) and are diagnosed based on location and identification of fat. Understanding the spectrum of appearances of the various benign musculoskeletal lipomatous lesions improves radiologic assessment and is vital for optimal patient management.

Chondroid lipoma: correlation of imaging findings and histopathology of an unusual benign lesion

The imaging findings of soft tissue tumours are often non-specific and generally require biopsy to differentiate between benign and malignant lesions. The finding of curvilinear, annular or amorphous mineralisation in an enlarging mass has sinister connotations. In this case report, we present the imaging findings with histological correlation of a chondroid lipoma, an unusual benign soft tissue tumour, which presented with radiographic evidence of calcification, an imaging finding not previously described. We also describe the ultrasound appearance and certain MR imaging appearances that have not been previously attributed to this tumour in the few reported cases.

Intermuscular chondrolipoma of the thigh: the diagnostic way of a rare entity

Cartilaginous metaplasia in lipomas (chondrolipoma) is rare and mainly encountered in large-sized, long-standing lipomas. Chondrolipomas can be found at almost any site of the body, particularly in the connecting tissue of the skeletal system, breast, pharynx, and nasopharynx. We report on an intermuscular tumor of the thigh in a patient who suffered from lipomatosis in his past medical history. We describe how the diagnosis of chondrolipoma was reached and discuss the differential diagnoses.