Recurrent Giant Intramuscular Lipoma of the Vastus Medialis Muscle: A Case Report and Comprehensive Review of the Literature

The aim of this study was to investigate the distribution of intramuscular giant lipomas in the functional compartments of the forearm and to compare their clinical, radiological and histopathological features with those reported in the current literature. The study included 12 patients who were surgically treated for intramuscular lipomas > 5 cm in size located in the forearm that had been confirmed histopathologically between April 2006 and March 2017. Data about the patients with respect to age, sex, affected side, localisation of the lipomas in the forearm functional compartments, size, histopathological features and recurrence were collected. According to the clinical complaints, direct radiography and magnetic resonance imaging were applied. The average diameter was 6.5 cm (range: 5.5-9 cm). All lipomas had a well-defined border. All the patients presented with soft-tissue masses that were painless in seven patients. Five patients had nerve compression symptoms. When the lipomas were classified according to the functional compartments of the forearm, six of them were located in the superficial volar compartment, two in the deep volar compartment, two in the deep dorsal compartment and two in the lateral compartment. All lipomas were surgically removed by marginal excision. None had complications or recurrence at a mean of 6.5 years follow-up (range: 1-12 years) after surgery. Intramuscular lipoma is a relatively uncommon tumour, especially in the forearm. Because of the proximity to the neurovascular structures in the forearm, excision of lipomas should be performed with care and include wide incisions. Additionally, knowing the anatomical features of the compartment where the lipoma is localised in the forearm is important in planning surgery to enable easier dissection of the lipoma and lessen the risk of damage to adjacent neurovascular structures. Level 4.

Dear Editor, Lipoma is the most common mesenchymal tumor. Although very common in other regions of the body, its occurrence in the hand is not as common. Some authors designate lipomas greater than 5 cm as giant lipomas. We recently read, with great interest, an article named “Giant hand lipoma revisited: Report of a thenar lipoma and its literature review” published in the Journal of Hand and Microsurgery [1]. In this letter to the editor, we would like to comment on a few important points regarding this specific article. First, we believe that although the size of the lipoma is important, the anatomical location is even more important when considering treatment and prognosis. Generally, lipomas can be divided into superficial or deep-seated. Deep-seated lipomas are located under the fascia and some of them can be further categorized into two very important subgroups: intermuscular and intramuscular lipomas. Frequently, deep-seated lipomas can grow to a large size and, therefore, the cutoff of 5 cm may not accurately represent their average size. In a study of thirteen deep-seated lipomas of the upper limb, Elbardouni et al. found that the mean size was 7 cm ranging from 5 to 20 cm [2]. In addition, Lee et al. in a sample of 6 intramuscular lipomas of the thenar and hypothenar muscles found the average size to be above 5 cm [3]. Although further evidence is needed to define the size of deep-seated lipomas in general and the hand in particular, size larger than 5 cm may be common and not necessarily represent malignancy. Furthermore, we believe that simply classifying the lipoma as “giant” may be confusing when no further description is provided. Perhaps, terms like “intermuscular giant lipoma”, “intramuscular giant lipoma” or “deep-seated giant lipoma” should be used instead. This is more descriptive and will address the location as well as the size of the tumor. Also, intermuscular lipomas are usually well encapsulated and grow expansively compared to intramuscular lipomas; the majority of which tend to grow infiltratevly. The term “infiltrative lipoma”, which has been used to describe these two subgroups, should be used only with the tumors which disclose infiltrative features to adjacent tissues. Second, the authors of this article state that “many of the giant lipomas have well-differentiated liposarcomatous components, which are difficult to differentiate form their benign counterpart”. Lipomas do not have well-differentiated liposarcomatous components regardless of their size. Even malignant transformation of a pre-existing mesenchymal tumor, including lipoma, has been questioned for a long time [4]. It is true, however, that it can be difficult to differentiate lipoma clinically, histologically and on imaging from well-differentiated liposarcoma. Insufficient sampling of a well-differentiated liposarcoma may erroneously misinterpret this neoplasm for lipoma and a radiologist who is inexperienced with that type of pathology may confuse the infiltrative intramuscular lipoma with liposarcoma [5]. In questionable cases, cytogenetic testing has been useful to differentiate the two groups on the bases of specific chromosomal aberrations. In conclusion, we believe that the term “giant lipoma” should be used in conjunction with other more descriptive terms such as “intramuscular”, “intermuscular” and “deep-seated” when referring to this pathology. Careful pre-surgical imaging evaluation may be pathognomonic in the majority of cases. Thorough histological examination and cytogenetic testing may avoid misdiagnosis of well-differentiated liposarcoma with deep-seated lipoma.

Intramuscular lipoma is a relatively uncommon condition and accounts for just 1,8% of all primary tumors of adipose tissue and less than 1% of all lipoma. This tumor arises within skeletal muscle fibers at various locations. However, giant intramuscular lipomas of biceps brachii muscle are rare tumors.
 A 48-years old man presented with a mass on his right upper-arm. The mass existed for one year and has since increased in size. On physical examination, the mass was pain upon palpation and completely mobile. Plain radiography, the soft tissue mass unremarkable. Computed tomography (CT) scan revealed a hypodense mass situated within right biceps brachii muscle with -72 until -83 Hounsfield. Magnetic resonance imaging (MRI), the mass was found inside of biceps brachii muscle. In T1- and T2- weighted images, the lesion area demonstrated high signal intensity, and SPAIR showed signal suppression similar to normal fat. The patient underwent radical excision of the lesion, which was found to be greater than 12 cm in size. Final pathology revealed intramuscular lipoma.
 A lipoma of greater than 5 cm is classified as a giant lipoma. Giant lipoma in the upper extremities and involving biceps brachii muscle are rare. The plain radiographs may either be unremarkable or may demonstrate a radiolucent soft tissue mass of fat opacity. On CT and MRI, the lipoma appears as an non-invasive mass with homogenous fat signal intensity. The main differential diagnosis of intramuscular lipomas is well-differentiated liposarcomas. The proper management is open excision. The pathological report is vital to confirm the diagnosis.
 We reported a rare case of giant intramuscular lipoma of biceps brachii who was successfully opened excision at our institute. CT scan and MRI can identify and localize these tumours, and facilitate the operative planning

Giant intramuscular thigh lipoma: A case report and review of literature

ABSTRACTThough lipomas are the most common benign soft tissue tumors, giant lipomas are rarely reported in the literature. Giant lipomas should be properly evaluated for any evidence of malignant transformation such as symptomatic, progressive growth in size, heterogeneity, hypervascularity, and irregular septation. Surgical resection should be considered in asymptomatic giant lipomas due to the risk of malignant transformation. Lipomas are the most common benign soft tissue tumors of adipose tissue and are typically small, slow‐growing, and asymptomatic. Giant lipomas, defined as lesions measuring ≥ 10 cm in one dimension or weighing ≥ 1 kg, are rare and may mimic malignancy due to their size and deep location. We report a case of a 58‐year‐old woman who presented with a progressively enlarging, asymptomatic mass over the right thigh for 7 years. Clinical examination revealed a firm mass measuring approximately 20 × 8 cm. Magnetic resonance imaging demonstrated a well‐defined, lobulated intermuscular lipomatous lesion measuring 24 × 8.5 × 7 cm involving the vastus medialis muscle, without features suggestive of malignant transformation or neurovascular encasement. Given the progressive enlargement and giant size of the tumor with local mass effect, marginal en‐bloc resection was performed through an anteromedial approach. Histopathological examination confirmed a benign encapsulated lipoma composed of mature adipocytes without atypia or malignancy. The postoperative course was uneventful, and no recurrence was noted at the 6‐month follow‐up. Although most lipomas are managed conservatively, giant lipomas warrant surgical excision for definitive diagnosis, symptom prevention, and exclusion of malignancy. A careful surgical planning, meticulous surgical resection, and close postoperative follow‐up can ensure excellent functional outcomes and prevent surgical complications.

Intramuscular lipomas and atypical lipomatous tumors (ALT) are common deep-seated lipomatous tumors of the chest wall and extremities. Distinguishing between these two entities can be difficult based on histologic analysis alone. However, the cytogenetic profiles of ALT and intramuscular lipomas are distinct. Correct classification is important, because aggressive local disease recurrence occurs more frequently in patients with ALT than in patients with intramuscular lipoma. The authors examined their single institutional experience and correlated their classification with clinical features and outcome. In the current study, 106 patients with deep-seated, well differentiated adipose tumors of the chest wall and extremities were classified as having ALT or intramuscular lipoma using a combined approach of histology and cytogenetics, if available. The classification was correlated with clinicopathologic features and follow-up data. Fifty-five patients were classified as having intramuscular lipoma and 51 were classified as having ALT. Classification did not correlate with age and gender (P = 0.28 and P = 0.96, respectively). Intramuscular lipomas were smaller than ALTs (P < 0.0001), but there was significant overlap between the 2 groups. ALT occurred preferentially in the lower extremity (P < 0.0009). Four percent of patients with intramuscular lipomas and 27% of patients with ALTs developed local disease recurrence (P = 0.0006). Disease recurrence did not correlate with patient age at diagnosis, patient gender, tumor size, and tumor location (P = 0.45, P = 0.26, P = 0.49, and P = 0.28, respectively). Within the subset of patients with ALTs, disease recurrence did not correlate with patient age at diagnosis, patient gender, or tumor location (P = 0.38, P = 0.54, and P = 0.86, respectively). Classification of deep-seated, well differentiated lipomatous tumors of the extremities and chest wall using a combined approach of histology and cytogenetics correlated well with biologic behavior/disease recurrence. This combined approach is advocated to better stratify patients for treatment purposes and follow-up.

Lipoma is a very common soft tissue neoplasm, but only infrequently found in the oral region. Intramuscular lipoma (IML) is a relatively common variant of lipoma. The most common site for IML is the large muscles of the extremities, and it is quite rare in the oral cavity. A case of IML affecting the floor of the mouth/tongue of a 42-year-old female is described. The patient presented with a 4 cm diameter yellow mass in the right side of the sublingual area. Axial and coronal magnetic resonance imaging demonstrated its infiltrating nature that can be distinguished from the ordinary well-encapsulated lesion. The lesion was excised with adequate surgical margins. Histopathologically, the lesion was composed of mature adipose tissue that infiltrated the muscle in a diffuse manner. No lipoblasts, atypical cells, or high mitotic index were found. There was no evidence of recurrence two years postoperatively. Review of the literature yielded that IML occurring in the sublingual region is extremely rare.

To review the literature on the diagnostic performance of clinical examination and magnetic resonance imaging (MRI) in detecting parametrial invasion and advanced stage disease (FIGO stage ≥ IIB) in patients with cervical carcinoma. Reports of studies were searched using the MEDLINE, EMBASE and Cochrane databases. Two observers reported on data relevant for analysis and methodological quality using the QUADAS scoring system. Publication bias was analysed using Deeks funnel plots. Covariates were added to the model to study the influence on the summary results of the technical and methodological aspects of the clinical examination and MRI. In total, 3,254 patients were included. Partial verification bias was often encountered. Pooled sensitivity was 40 % (95 % CI 25-58) for the evaluation of parametrial invasion with clinical examination and 84 % (95 % CI 76-90) with MRI, 53 % (95 % CI 41-66) for the evaluation of advanced disease with clinical examination, and 79 % (95 % CI 64-89) with MRI. Pooled specificities were comparable between clinical examination and MRI. Different technical aspects of MRI influenced the summary results. MRI is significantly better than clinical examination in ruling out parametrial invasion and advanced disease in patients with cervical carcinoma. • MRI has a higher sensitivity than clinical examination for staging cervical carcinoma. • Clinical examination and MRI have comparably high specificity for staging cervical carcinoma. • Quality of clinical examination studies was lower than that of MRI studies. • The use of newer MRI techniques positively influences the summary results. • Anaesthesia during clinical examination positively influences the summary results.

To determine the diagnostic performances of clinical examination and selective magnetic resonance imaging in the evaluation of intraarticular knee disorders in children and adolescents we compared them with arthroscopic findings in a consecutive series of pediatric patients (< or = 16 years old). Stratification effects by patient age and magnetic resonance imaging center were examined. There were 139 lesions diagnosed clinically, 128 diagnosed by magnetic resonance imaging, and 135 diagnosed arthroscopically. There was no significant difference between clinical examination and magnetic resonance imaging with respect to agreement with arthroscopic findings (clinical examination, 70.3%; magnetic resonance imaging, 73.7%), overall sensitivity (clinical examination, 71.2%; magnetic resonance imaging, 72.0%), and overall specificity (clinical examination, 91.5%; magnetic resonance imaging, 93.5%). Stratified analysis by diagnosis revealed significant differences only for sensitivity of lateral discoid meniscus (clinical examination, 88.9%; magnetic resonance imaging, 38.9%) and specificity of medial meniscal tears (clinical examination, 80.7%; magnetic resonance imaging, 92.0%). For magnetic resonance imaging, children younger than 12 years old had significantly lower overall sensitivity (61.7% versus 78.2%) and lower specificity (90.2% versus 95.5%) compared with children 12 to 16 years old. There was no significant effect of magnetic resonance imaging center. In conclusion, selective magnetic resonance imaging does not provide enhanced diagnostic utility over clinical examination, particularly in children, and should be used judiciously in cases where the clinical diagnosis is uncertain and magnetic resonance imaging input will alter the treatment plan.

Background: Preoperative identification of pathologic complete response (pCR) is important to decrease surgical morbity. The objective of this study was to determine diagnostic validity of clinical examination and magnetic resonance imaging (MRI) in determining pathologic response in patients with breast cancer subtypes HER 2 overexpressed and triple negative after neoadjuvant therapy. Methods: This is a cross- sectional study, with a sample comprising 72 patients woman with HER-2 overexpressed or triple negative breast submitted to neoadjuvant treatment at Hospital Sirio Libanês between January 2005 and December 2012. All patients were clinically evaluated by a group of seven breast surgeons. Double reading of breast MRI was performed in three periods: at the beginning of treatment, after the second cycle of chemotherapy and after treatment. Photographic record of the breast was done before and after chemotherapy. HER-2 and hormone receptors were assessed using immunohistochemistry. Sensitivity (Se), specificity (Sp), positive predictive value (PPV), and negative predictive value (VNP) were estimated using pathology as the gold standard. Area under ROC curve and the corresponding 95% confidence intervals (95% CI) were calculated. Results: Thirty- two patients (44,4%) had triple negative tumors while 40 (55.6%) overexpressed HER-2. Among those with triple negative tumors, clinical examination evidenced a completed response in 31.2% (10/32) of the cases. pCR was observed in 3 patients (9.4%). Diagnostic validity measures for clinical examination were: Se= 100%, Sp=75.9%, PPV=42.9% and NPV=100%. In this group, MRI detected a complete response in 7 cases (21.9%). Therefore, MRI presented a Se=66.8%, Sp=82.8%, PPV 28.6% and NPV= 96%. Area under ROC curve was 0.88 (95% CI 0.80-0.96) and 0.75 (95% ci 0.41-1.00) for clinical examination and MRI, respectively. Among woman with tumors over expressing HER-2, complete response was observed through clinical examination in 45% (18/40) of these cases, showing Se= 100%, Sp=71%, PPV=100% and NPV=70,9%. In this group, complete radiological response was noted in 8 cases (20%). Therefor, MRI had Se=33.3%, Sp=83.9%, PPV 37.5% and NPV=96%. Area under ROC curve was 0.85 (95% CI 0.77-0.94) and 0.59 (95% CI 0.41-0.76) for clinical examination and MRI, respectively. Conclusions: Our findings demonstrate that clinical examination is superior to MRI to predict pCR for woman wth tumor overexpressing HER-2, while for tumor patients with triple negative tumors the two methods were equivalent. Therefore, clinical examination can be used with MRI to monitor tumor response to neoadjuvant chemotherapy and also to determine the best course of surgical action. Monitoring and assessment, however, are better when both methods are associates. Citation Format: Andrade FEM, De Barros ACS, Docema MF, Heinzen RN, De Andrade JZ, Nimir C, Mano MDS, Gianotti D, Ribeiro KDCB. Clinical examination and breast MRI as predictors of pathologic complete response post neoadjuvant therapy in HER2 overexpressed subtypes and triple negative breast cancer [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P3-02-11.

INTRAMUSCULAR VARIANT OF LIPOMA IN THE TONGUE: A CASE REPORT

MRI Diagnosis of Pelvic Organ Prolapse Compared with Clinical Examination

Objective:The purpose of the present study was to determine the local recurrence rate, risk of dedifferentiation, and distant metastasis after surgical excision of intramuscular lipomas (IML) and atypical lipomatous tumors (ALT). Subjects and Methods: We retrospectively assessed all IML and ALT surgically removed from the extremities or trunk wall in our clinic between 1997 and 2006. Data from 141 patients with IML and 35 patients with ALT were extracted from the National Pathology Registry and patient files. Results: IML and ALT recurred in 10 and 6 tumors, respectively. No metastases were observed in either group. The 5- and 10-year local recurrence-free survival rates were 97.1% (94.3–99.9) and 94.8% (CI: 91.1–98.6) for IML and 84.6% (CI: 72.1–97.1) and 81.1% (CI: 67.6–94.8) for ALT, respectively. ALT were found to dedifferentiate in 2/35 cases. Conclusion: Both IML and ALT showed a low recurrence rate when removed surgically from the extremities or trunk wall with intended marginal resection. No distant metastases were observed in any of the groups. It, therefore, seems safe to treat these tumors with marginal resection.

The role of imaging modalities in the diagnosis, differential diagnosis and clinical assessment of peripheral joint osteoarthritis

Introduction: Lipomas represent the most frequent type of soft tissue tumor. A giant lipoma is typically defined as a lesion measuring ≥10 cm in at least one dimension or weighing more than 1000 g. While these tumors are often asymptomatic, they may occasionally produce compressive symptoms, including neuropathic pain or motor impairment, particularly when located in areas that affect gait or mobility. Presentation of case: We report the case of a 48-year-old woman with no relevant past medical history who presented with a nine-year history of a progressively enlarging, painless mass on the right thigh. The lesion had gradually increased in size, leading to discomfort and limitation of daily activities. Magnetic resonance imaging (MRI) revealed a well-defined intramuscular , adipose mass measuring 26.5 × 12.5 × 6 depending on the rectus femoris muscle, well defined and encapsulated, with the same signals as fat. Its lower pole reaches the myotendinous junction of the quadriceps, and its upper pole reaches the trochanteric massif.. Complete excision with clear margins was achieved while preserving the affected musculature. The postoperative course was uneventful, and the patient demonstrated a satisfactory functional recovery. Discussion: Lipomas are common benign tumors originating from adipose tissue. Their considerable size or deep extension can pose challenges in surgical management. Although malignant transformation is rare, careful excision is warranted. Close collaboration between radiologists and surgical pathologists is essential, particularly in assessing muscular involvement and identifying any infiltrative growth patterns. Conclusion: Giant lipomas should always prompt consideration of potential malignant transformation. Radiological assessment usually provides sufficient information to determine the necessity of a biopsy, thereby preventing unnecessary invasive procedures. During surgical excision, maintaining a margin of approximately 1 cm of healthy tissue is recommended to minimize the risk of local recurrence.