MRI appearances of common benign soft-tissue tumours

Radiological diagnosis of median nerve lipoma: A case report from Palestine

Lipomas are benign neoplasms that develop from adipocyte-rich adipose tissue. They affect up to 2% of the population and make up about 50% of all soft-tissue neoplasms. The most common locations for them to appear asymptomatically are the neck, upper back, proximal limbs, and chest. They typically start off as single, distinct, movable lumps. A 50-year-old man who had pain and edema in his right wrist came to our hospital. The patient's history dates back to 9 years ago, when he first began to complain of swelling in his wrist rest but no discomfort. According to a clinical examination, he has a soft, non-painful bump in his right wrist. After being monitored for 9 years with no change in the size of the tumor on his right wrist, the patient started to experience right hand pain and a weak right grasp. Magnetic resonance imaging is the preferred visualization method for examining hand tumors; it is advised to perform a preoperative complementary ultrasound or magnetic resonance imaging investigation in cases of atypical findings or nonfrequent locations of nerve compression, which are clinically interpreted as idiopathic compression.

The safety of primary surgical excision of small deep indeterminate musculoskeletal soft tissue masses

OBJECTIVE

To determine the suitability of primary excision of small indeterminate deep soft tissue masses presenting to a tertiary musculoskeletal oncology service.

METHODS AND MATERIALS

Review of all patients referred to a specialist musculoskeletal oncology service over a 20-month period with a deep indeterminate soft tissue mass by non-contrast MRI criteria that was recommended for primary surgical excision due to relatively small size (<30 mm). Data collected included age, gender, site and maximal size of the lesion, and final histological diagnosis for excised lesions.

RESULTS

85 patients were included, mean lesion size being 12 mm (range 5-29 mm). Primary surgical resection had been undertaken in 69 cases (81.2%) by the conclusion of data collection, 36 males and 33 females with mean age of 45.6 years (range 11-80 years). Of these, 11 cases (15.9%) were non-neoplastic, 53 (76.8%) were benign, 1 (1.4%) was intermediate grade, while 4 (5.8%) were malignant including 3 synovial sarcomas. Two of these were treated with re-excision of the tumour bed showing no residual disease, with no evidence of local recurrence at a mean of 10.7 months post-excision.

CONCLUSION

Primary surgical excision of small deep soft tissue masses that are indeterminate by non-contrast MRI criteria is considered a safe procedure when undertaken in a specialist musculoskeletal oncology service, with only 4 of 69 cases (5.8%) being malignant.

ADVANCES IN KNOWLEDGE

Small indeterminate deep soft tissue masses can safely be treated with primary excision in the setting of a specialist musculoskeletal oncology service.

Small Subcutaneous Soft Tissue Tumors (<5 cm) Can Be Sarcomas and Contrast-Enhanced Ultrasound (CEUS) Is Useful to Identify Potentially Malignant Masses

Subcutaneous masses smaller than 5 cm can be malignant, in contrast with the international guidelines. Ultrasound (US) and magnetic resonance imaging (MRI) are useful to distinguish a potentially malignant mass from the numerous benign soft tissue (ST) lesions. Contrast-enhanced ultrasound (CEUS) was applied in ST tumors, without distinguishing the subcutaneous from the deep lesions. We evaluated CEUS and MRI accuracy in comparison to histology in differentiating malignant from nonmalignant superficial ST masses, 50% smaller than 5 cm. Sensitivity, specificity, and positive and negative predictive values (PPV, NPV) with their 95% confidence intervals (CI) were calculated. Of malignant cases, 44.4% measured ≤5 cm. At univariate analysis, no statistically significant differences emerged between benign and malignant tumors in relation with clinical characteristics, except for relationship with the deep fascia (p = 0.048). MRI accuracy: sensitivity 52.8% (CI 37.0, 68.0), specificity 74.1% (CI 55.3, 86.8), PPV 73.1% (CI 53.9, 86.3), and NPV 54.1% (CI 38.4, 69.0). CEUS accuracy: sensitivity 75% (CI 58.9, 86.3), specificity 37% (CI 21.5, 55.8), PPV 61.4% (CI 46.6, 74.3), and NPV 52.6% (CI 31.7, 72.7). CEUS showed a sensitivity higher than MRI, whereas PPV and NPV were comparable. Also, masses measuring less than 5 cm can be malignant and referral criteria for centralization could be revised.

Small indeterminate superficial soft tissue masses: relationship between depth and histological grade

OBJECTIVE

To determine whether the location of a small, indeterminate soft tissue mass within the subcutaneous compartment is related to its histological grade.

METHODS

All Sarcoma Service referrals over a 12 month period of small (<3 cm) superficial soft tissue masses, indeterminate by MRI evaluation which subsequently underwent primary excision biopsy were included. Lesions were categorised by their anatomical location in the subcutaneous compartment. Histopathological diagnoses were categorized according to12 WHO 2013. χ2 statistical analysis was performed to determine the relationship between lesion depth and histological grade.

RESULTS

The study included 43 patients, mean age 42 years (range 15-71 years). Within the subcutaneous compartment, 16 lesions were categorized as superficial, 9 lesions central and 18 lesions deep, of which 9 were non-neoplastic, 29 benign, 1 intermediate-grade and 4 malignant. Location in the deep aspect of the subcutaneous compartment was associated with a higher risk of intermediate or malignant histology (p = 0.02).

CONCLUSION

The location of a small, indeterminate soft tissue mass within the subcutaneous compartment may be an indicator of histological aggressiveness. Lesions in the deep subcutaneous compartment are more likely to be intermediate-grade/malignant lesions. Therefore, if considering excision biopsy as definitive treatment, a wider margin may be appropriate.

ADVANCES IN KNOWLEDGE

Small, indeterminate soft tissue masses can be aggressive and the anatomical depth within the subcutaneous tissue may be a potential indicator of histological aggressiveness.

The incidence and diagnostic relevance of chemical shift artefact in the magnetic resonance imaging characterisation of superficial soft tissue masses

OBJECTIVE

Chemical shift artefact (CSA) is often encountered during MRI evaluation of superficial soft tissue masses. The study aim was to determine the incidence and diagnostic relevance of CSA in a consecutive series of superficial soft tissue masses referred to a specialist musculoskeletal sarcoma service.

METHODS

All patients referred over a 6 month period with a non-lipomatous superficial soft tissue mass were prospectively analysed. Patients characteristics (age, gender), lesion features (anatomical location, size, relationship to the skin and deep fascia), presence of CSA and final histopathological diagnosis were collected. The presence of CSA was statistically analysed against these clinical, imaging and histopathological variables.

RESULTS

128 patients fulfilled the inclusion criteria [63 males, 65 females; mean age = 50.6 years (7-96 years)]. CSA was present in 50 cases (39.1%) overall, but in 39 (41.5%) of 94 cases with histological diagnosis. There was no statistically significant relationship to any assessed variable apart from relationship to the deep fascia, CSA being more frequent in lesions contacting the fascia compared to lesions contacting both skin and fascia (p-value 0.02). In particular, the presence of CSA did not allow differentiation between non-malignant and malignant lesions.

CONCLUSION

The presence of CSA is a not infrequent finding in the MRI assessment of superficial soft tissue masses but does not appear to be of any significance in differentiating between non-malignant and malignant lesions.

ADVANCES IN KNOWLEDGE

CSA is a relatively common finding in association with superficial soft tissue masses, but does not indicate a particular histological diagnosis or help in the differentiation of non-malignant from malignant lesions.

Surgical considerations when reporting MRI studies of soft tissue sarcoma of the limbs

Soft tissue sarcomas (STS) are rare tumours that require prompt diagnosis and treatment at a specialist centre. Magnetic resonance imaging (MRI) has become the modality of choice for identification, characterisation, biopsy planning and staging of soft tissue masses. MRI enables both the operating surgeon and patient to be optimally prepared prior to surgery for the likelihood of margin-negative resection and to anticipate possible sacrifice of adjacent structures and consequent loss of function. The aim of this review is to aid the radiologist in performing and reporting MRI studies of soft tissue sarcomas, with particular reference to the requirements of the surgical oncologist.

[Imaging characteristics of malignant and benign lesions of skeletal muscle]

There are many different tumors and tumor-like lesions with variable biological behavior that may affect the skeletal musculature. The aim of this study was to review the different intramuscular lesions and to provide a classification based on their radiological patterns. Intramuscular lesions can present as solid, liquid, semiliquid or fat equivalent manifestations and also as diffuse muscle enlargement and muscle calcification. Additionally, lesions with mixed patterns of the aforementioned alterations can also occur. Benign and malignant muscle lesions can often manifest with identical radiological patterns, which is why a certain differentiation is often difficult. A systematic radiological description and when possible assignment with respect to etiology and dignity depending on the patient history is necessary in order to recommend a subsequent histological confirmation or to avoid unnecessary confirmation.

Small, superficial, indeterminate soft-tissue lesions as suspected sarcomas: is primary excision biopsy suitable?

OBJECTIVE

Suspected soft-tissue sarcomas are typically investigated using magnetic resonance imaging (MRI), with a view to planning image-guided core needle biopsy for confirmation of the histological diagnosis. Indeterminate superficial lesions may be small and therefore potentially difficult to biopsy safely, such lesions possibly being more amenable to primary excision biopsy. The aim of this study is to determine the suitability of this practice in the setting of a specialist sarcoma service.

MATERIALS AND METHODS

All patients referred over a 12-month period to the sarcoma service with a small (<3-cm), indeterminate, superficial soft-tissue mass according to MRI criteria, or a small lesion of the hand or foot deemed unsafe for percutaneous biopsy, and who underwent primary excision biopsy were included. The histology results were categorized into neoplastic and non-neoplastic lesions, and assessed for resection completeness.

RESULTS

Fifty-eight patients fulfilled the inclusion criteria from all patients referred to the sarcoma service in a 12-month period. Of these, 42 out of 58 (72.4%) had benign neoplasms, 4 out of 58 (6.9%) had malignant tumours, 2 out of 58 (3.4%) an intermediate grade lesion, while 10 out of 58 (17.2%) were non-neoplastic. All 4 malignant lesions were completely excised at the time of excision biopsy.

CONCLUSIONS

Primary excision biopsy of small, indeterminate soft-tissue masses within the setting of a specialist sarcoma service is a suitable management option. Only a small proportion of small superficial soft-tissue lesions with indeterminate MRI features are malignant tumours.

Benign tumors affecting the median nerve. Case series report of diagnostic and surgical strategies

Objective

The aim of this study was to describe the strategies adopted in this institution to diagnose and treat patients with benign tumors affecting the median nerve.

Methods

A retrospective chart review study of all patients operated on between 2010 and 2015. Histology, symptoms, complementary exams, surgical techniques performed, and demographic characteristics were analyzed.

Results

Fifty-four patients were included in the study. There were three neurofibromas, six schwannomas, 15 lipofibromatous hamartomas, three hemangiomas, 12 lipomas, one benign fibrohistiocytoma, and 14 synovial cysts. Complete tumoral resection was performed in 32 cases, partial resection in five, segmented nerve resection in one, nerve decompression in eight, and amputation for macrodactyly in eight.

Conclusions

The most important recommendations on treating benign tumors of the median nerve are related to the clinical symptoms, tumoral growth, and tumoral nature. The surgical approach resulted in good function for 60% of the patients. However, lipofibromatous hamartomas, hemangiomas, and neurofibromas were associated with preoperative functional deficit. It may be inferred that the diagnosis and treatment of these tumors should be performed earlier.

Peripheral nerve lipoma: Case report of an intraneural lipoma of the median nerve and literature review

Adipose lesions rarely affect the peripheral nerves. This can occur in two different ways: Direct compression by an extraneural lipoma, or by a lipoma originated from the adipose cells located inside the nerve. Since its first description, many terms have been used in the literature to mention intraneural lipomatous lesions. In this article, the authors report a case of a 62-year-old female who presented with an intraneural median nerve lipoma and review the literature concerning the classification of adipose lesions of the nerve, radiological diagnosis and treatment.

[Retroperitoneal lipoblastoma in an infant. A case report]

INTRODUCTION

Lipoblastoma is a benign neoplasia of the adipose tissue. It is a rare conditionand almost exclusively presents in children under 3 years old. It usually occurs in extremities as a painless volume increase of progressive growth, with the definitive diagnosis being established by pathological and cytogenetic analysis. The treatment of choice is complete resection, and follow-up period of up to five years is recommended due to a recurrence of up to 25%.

OBJECTIVE

To present an unusual location of this uncommon condition in an infant, and review the related literature.

CASE REPORT

A sixteen-month child with an increase in abdominal growth of six-months progression, associated with a decreased food intake, and with no other symptoms. The imaging study revealed a lipoid-like image compromising almost the entire abdominal cavity, very suggestive of lipoblastoma. A resection was performed on an 18cm diameter retroperitoneal tumour that rejected the adjacent organs. Histological analysis was enough to confirm diagnosis without the need for cytogenetic analysis. The follow-up showed no recurrence of the disease.

CONCLUSION

Given the rarity of this disease and its unusual presentation, we communicate this clinical case, in order to be considered in the differential diagnosis of abdominal mass in chilhood.

Carpal tunnel syndrome caused by lipoma: a case report

Lipoma is a relatively frequent, benign soft-tissue tumor rarely located in the hand. A lipoma of the hand causing a carpal tunnel syndrome by compression of the median nerve is exceptional. We report the case of a 70-year-old female presenting with a carpal tunnel syndrome. A compression of the median nerve by a lipoma was discovered during surgery. Transverse carpal ligament release with lipoma excision and neurolysis of the median nerve were performed. Histopathological study of the resected mass was consistent with a lipoma. Two-month postoperatively, the patient recovered full hand function with entire disappearance of acroparesthesia. Carpal tunnel syndrome caused by space occupying lesions is rare. Diagnosis is difficult, usually based on the clinical study, electrophysiology and magnetic resonance imaging (MRI). Transverse carpal ligament release and excision of lipoma provides excellent functional recovery.

Retroperitoneal low-flow vascular malformations: characteristic MRI findings correlated with histopathological findings

PURPOSE

To evaluate the MRI findings of retroperitoneal low-flow vascular malformations (RLVMs) correlated with histopathological findings.

METHODS

Two radiologists reviewed the MRI findings of 4 RLVMs (3 with capillary malformations and 1 with a venous malformation). First, they evaluated the visibility, signal intensities, and signal homogeneity of each lesion on non-fat-suppressed breath-hold T2-weighted single-shot fast spin-echo (non-FS SSFSE) images and fat-suppressed T2-weighted fast spin-echo (FS T2-weighted FSE) images. Second, the kinetic patterns and the internal enhancement patterns were analyzed for each lesion on multi-phasic contrast-enhanced (CE) images. After these image analyses, the MRI findings were correlated with the histopathological findings.

RESULT

Histopathologically, the 4 RLVMs did not exhibit remarkable degeneration and were present in the retroperitoneal fat tissue without clear capsules. On the non-FS SSFSE images, 3 of the 4 RLVMs could not be discriminated from the surrounding retroperitoneal fat tissue (invisible), and the remaining lesion was barely visible with an indistinct margin. On the FS T2-weighted FSE images, however, all the RLVMs were clearly visualized as homogeneous high-signal intensities. On the multi-phasic CE images, all the capillary malformations exhibited fast enhancement, while a venous malformation showed slow enhancement. Furthermore, the RLVMs tended to exhibit a centripetal filling pattern.

CONCLUSION

The RLVMs blended in with the surrounding retroperitoneal fat tissue on non-FS SSFSE images, like phantoms, whereas they were clearly visualized on FS T2-weighted FSE images. On multi-phasic CE images, the RLVMs tended to exhibit a centripetal filling pattern. These imaging features may be useful diagnostic clues for RLVMs.

Malignant and benign lesions of the skeletal musculature

There are several tumors and tumorlike conditions with variable biological behavior that may involve the skeletal musculature. The aim of this work was to review different intramuscular lesions and to provide a classification of muscle lesions based on their radiological patterns as well as to provide as a pictorial essay the imaging characteristics of typical muscle lesions. Radiologically, intramuscular lesions can manifest as solid masses, liquid or semiliquid masses, fat-containing lesions, diffuse muscle enlargement, and muscle calcifications. Additionally, lesions with mixed patterns can also occur. It is noteworthy that different malignant or benign muscle lesions can manifest with identical radiological patterns.

Median nerve compression in carpal tunnel caused by a giant lipoma

A lipoma is a common, benign soft-tissue tumor that rarely arises in the upper limb. When one does occur in the hand, the location of the lipoma can cause nerve compression, which can mimic carpal tunnel symptoms. Magnetic resonance imaging is the visualization modality of choice for diagnosis and surgical planning of lipomas. Surgical resection is recommended to relieve the neurological manifestations of this disease. The surgeon should always suspect liposarcoma first before voluminous, atypical, or recurrent tumors are considered.

The role of MRI in image-guided needle biopsy of focal bone and soft tissue neoplasms

Magnetic resonance imaging (MRI) plays a critical role in the management pathway of both soft tissue and bone neoplasms, from diagnosis through to post-treatment follow-up. There are a wide range of surgical, oncological, and combined treatment regimes but these rely on accurate histopathological diagnosis. This article reviews the role of MRI in the planning of image-guided needle biopsy for suspected soft tissue and bone tumors.

Assessment of referrals into the soft tissue sarcoma service: evaluation of imaging early in the pathway process

Purpose. To prospectively evaluate regional referrals into a soft tissue sarcoma service from outside the tertiary centre with local hospital imaging. Materials and Methods. Consecutive referrals were prospectively assessed for: patient demographics, source, referral date, date received by Multidisciplinary Team (MDT), lesion size, local radiology, MDT radiology and final diagnoses. Radiology diagnosis was categorised benign, indeterminate or malignant by consensus. Delays were defined as >10 days. Results. 112 patients were included with high correlation between local and MDT radiology categrorisation and histology (P = 0.54 and P = 0.49, resp.). There was only a trend for MDT radiology diagnosis to downgrade local imaging diagnosis (n = 15, P > 0.05). 48 cases (43%) had ultrasound and MRI at referral and 20 (18%) ultrasound only. 85% of cases were benign (lipoma most common), 15% malignant (sarcoma most common). Delay occurred in 34% of cases. Discussion. In comparison to previous series these results show a reduction in benign lesions, increased biopsy and malignancy rate for lesions referred to a tertiary centre when imaging is performed and reviewed by local radiologists. Advances in Knowledge. Imaging triage of soft tissue masses can decrease benign referral rates and increase the proportion of indeterminate and malignant lesions referred to specialist centres.

Soft-tissue tumors and tumorlike lesions: a systematic imaging approach

Soft-tissue lesions are frequently encountered by radiologists in everyday clinical practice. Characterization of these soft-tissue lesions remains problematic, despite advances in imaging. By systematically using clinical history, lesion location, mineralization on radiographs, and signal intensity characteristics on magnetic resonance images, one can (a) determine the diagnosis for the subset of determinate lesions that have characteristic clinical and imaging features and (b) narrow the differential diagnosis for lesions that demonstrate indeterminate characteristics. If a lesion cannot be characterized as a benign entity, the lesion should be reported as indeterminate, and the patient should undergo biopsy to exclude malignancy.