Low-grade Fibromyxoid Sarcoma Research Articles

Utility of LEF1 to differentiate desmoid fibromatosis from its histologic mimics.

Diagnosis of desmoid-type fibromatosis (DF) may be challenging on biopsy due to morphologic overlap with reactive fibrosis (scar) and other uniform spindle cell neoplasms. Evaluation of nuclear β-catenin, a surrogate of Wnt pathway activation, is often difficult in DF due to weak nuclear expression and high background membranous/cytoplasmic staining. Lymphoid enhancer-factor 1 (LEF1) is a recently characterized effector partner of β-catenin which activates the transcription of target genes. We investigated the performance of LEF1 and β-catenin immunohistochemistry in a retrospective series of 156 soft tissue tumors, including 35 DF, 3 superficial fibromatosis, and 121 histologic mimics (19 soft tissue perineurioma, 8 colorectal perineurioma, 4 intraneural perineurioma, 26 scars, 23 nodular fasciitis, 6 low-grade fibromyxoid sarcomas, 6 angioleiomyomas, 5 neurofibromas, 5 dermatofibrosarcoma protuberans, 3 low-grade myofibroblastic sarcomas, 3 synovial sarcomas, 3 inflammatory myofibroblastic tumors, 2 schwannomas, and 1 each of Gardner-associated fibroma, radiation-associated spindle cell sarcoma, sclerotic fibroma, dermatofibroma, and glomus tumor). LEF1 expression was not only seen in 33/35 (94%) of DF but also observed in 19/23 (82%) nodular fasciitis, 7/19 (37%) soft tissue perineurioma, 2/3 (66%) synovial sarcoma, and 6/26 (23%) scar, as well as in 1 radiation-associated spindle cell sarcoma. The sensitivity and specificity of LEF1 IHC for diagnosis of DF were 94% and 70%, respectively. By comparison, β-catenin offered similar sensitivity, 94%, but 88% specificity. Positivity for LEF1 and β-catenin in combination showed sensitivity of 89%, lower than the sensitivity of β-catenin alone (94%); however, the combination of both LEF1 and β-catenin improved specificity (96%) compared to the specificity of β-catenin alone (88%). Although LEF1 has imperfect specificity in isolation, this stain has diagnostic utility when used in combination with β-catenin.

Supraclavicular Artery Island Flap for Treatment of Cervical Wound Defects and Persistent Cerebrospinal Fluid Leaks: A Technical Note and Systematic Review of the Literature

BackgroundSoft tissue defects and persistent cerebrospinal fluid (CSF) leaks can create complications after cervical spinal surgery. The supraclavicular artery island (SAI) flap is useful in closing tissue defects, particularly in these complex surgeries and multiple reinterventions. However, technical reports in this context are scarce. We describe application of the SAI flap technique to control persistent CSF leak in the first documented instance (to our knowledge) of a low-grade fibromyxoid sarcoma (LGFMS) in the cervical epidural space. Additionally, we conducted a comprehensive review of PubMed, Embase, and Google Scholar from their earliest records through December 17, 2023 using combined terms, “supraclavicular artery island flap AND spine” and “supraclavicular AND flap AND spine”. Technical NoteA 56-year-old woman with arm pain and weakness presented with a cervical epidural mass extending from C4–C6 and associated spinal cord compression. She underwent a 3-level corpectomy and tumor resection. Primary dural closure was impossible due to the dural invasion, and reintervention with an SAI flap and definitive lumboperitoneal shunting were required to control and seal the CSF leak. Systematic Literature ReviewSeven case reports describing SAI flap for spinal surgery complications were identified. The indications in those cases were correcting esophageal and hypopharyngeal perforations after cervical fusion and discectomy and persistent soft tissue coverage after cervical instrumentation. ConclusionThe SAI flap technique provided wound defect coverage in this case and is suitable for addressing issues such as persistent CSF leaks or soft tissue coverage after cervical spine surgery.

Novel KMT2B gene mutation in MUC4 positive low-grade fibromyxoid sarcoma

BackgroundLow-grade Fibromyxoid Sarcoma(LGFM)is a rare fibrosarcoma, which mainly occurs in young people and is mostly seen in the trunk and limbs. The tumor is usually FUS-CREB3L2 fusion caused by t(7;16)(q32-34;p11)chromosome translocation, and rarely FUS-CREB3L1 and EWSR1-CREB3L1 fusion. MUC4 diffuse strong positive can be used as a specific index of LGFM. LGFM is similar to Sclerosing Epithelioid Fibrosarcoma(SEF) and may have the same origin.Case presentationWe report a case of LGFM in the chest wall. A female who is 59 years old. In 2016, CT showed dense nodule shadow and focal thickening of the left pleura, the patient underwent surgery, Pathological report that low to moderate malignant fibrosarcoma(fibromyxoid type). The CT re-examination in 2021 showed that the tumors on the left chest wall were significantly larger than before. Pathological examination showed the disease is composed of alternating collagen like and mucinous areas. Under high-power microscope, the tumor cells are consistent in shape, spindle or short spindle, and the tumor cells are arranged in bundles. In local areas, the density of tumor cells is significantly increased, mixed with collagen fibers, and small focal SEF appear. The result of immunohistochemistry showed that SMA, Desmin, CD34, STAT6, S100, SOX10, HMB45 and Melan A were negative, EMA was weakly positive, MUC4 was diffuse and strongly positive, and Ki67 index was low (3%).ConclusionSequencing results showed that MET, EGFR, KMT2B and RET gene were mutated in LGFM, and KMT2B gene had cancer promoting effect, but there was no literature report in LGFM, which may be of certain significance for the diagnosis and treatment of LGFM.

Soft tissue tumours of the penis. The 30-year Istituto Nazionale Tumori di Milano experience.

Small series and individual cases of penile soft tissue tumours are reported in the literature: these are rare tumours that represent less than 5% of all penile tumours. Penile soft tissue tumours were collected from the archive of the Department of Pathology at the Istituto Nazionale dei Tumori of Milan between January 1990 and October 2021. All available medical records were retrieved and reviewed to obtain clinical information. Our series refers to the 30-year experience of highlighting the heterogeneity in the presentation and microscopic features of these rare sarcomas. 18 penile soft tissue tumours are described, 4 benign and 14 malignant. The mean age at diagnosis was 58.2 years (range 24-96 years) and 53.6 years among malignancies (range 24-89). The most frequent histotype was Kaposi's sarcoma (nr = 4) and very unusual histotypes were observed, namely low-grade fibromyxoid sarcoma, synovial sarcoma, proximal type epithelioid sarcoma and the first reported case of dedifferentiated liposarcoma of the penis. Among sarcomas of the genitourinary tract, tumours of the soft tissues of the penis are the rarest. Penile sarcomas can present at a young age. Kaposi's sarcoma in HIV-negative patients has a favorable outcome, while deep sarcomas have an aggressive behavior and poor prognosis.

Familial multiple endocrine neoplasia type 1 with intrathoracic low-grade fibromyxoid sarcoma

BackgroundMultiple endocrine neoplasia type 1 (MEN1) is a hereditary tumor syndrome characterized by endocrine tumors with mainly a parathyroid, pancreatic, or anterior pituitary origin. Low-grade fibromyxoid sarcoma (LGFMS) is a rare low-grade soft tissue tumor. There is one known report of a patient with MEN1 complicated by LGFMS, which is very rare. Our report represents the second documented case, providing valuable insights.Case presentationA 31-year-old man with the chief complaint of a cough underwent chest contrast-enhanced computed tomography, which revealed a giant hypoabsorptive tumor with a maximum diameter of 23 cm in the left thoracic cavity. The patient was diagnosed with MEN1, as he also possessed a pancreatic neuroendocrine tumor and parathyroid tumor, and because his father had been found to have MEN1. To control hypercalcemia, surgery for the parathyroid tumor was initially performed, followed by surgical resection of the giant thoracic tumor for diagnosis and treatment. Histopathological examination findings of the tumor resulted in a diagnosis of LGFMS.ConclusionWe experienced a very rare MEN1 with LGFMS. Although endocrine tumors generally occur more frequently in MEN1, non-endocrine tumors such as the present case should also be noted, reinforcing the importance of systemic imaging scrutiny in addition to early diagnosis and long-term follow-up of MEN1 patients.

The Regulatory Network of CREB3L1 and Its Roles in Physiological and Pathological Conditions.

CREB3 subfamily belongs to the bZIP transcription factor family and comprises five members. Normally they are located on the endoplasmic reticulum (ER) membranes and proteolytically activated through RIP (regulated intramembrane proteolysis) on Golgi apparatus to liberate the N-terminus to serve as transcription factors. CREB3L1 acting as one of them transcriptionally regulates the expressions of target genes and exhibits distinct functions from the other members of CREB3 family in eukaryotes. Physiologically, CREB3L1 involves in the regulation of bone morphogenesis, neurogenesis, neuroendocrine, secretory cell differentiation, and angiogenesis. Pathologically, CREB3L1 implicates in the modulation of osteogenesis imperfecta, low grade fibro myxoid sarcoma (LGFMS), sclerosing epithelioid fibrosarcoma (SEF), glioma, breast cancer, thyroid cancer, and tissue fibrosis. This review summarizes the upstream and downstream regulatory network of CREB3L1 and thoroughly presents our current understanding of CREB3L1 research progress in both physiological and pathological conditions with special focus on the novel findings of CREB3L1 in cancers.

The Expression of Mucin-4 (MUC4) in Sarcomas Apart From Sclerosing Epithelioid Fibrosarcoma and Low-Grade Fibromyxoid Sarcoma.

Background Low-grade fibromyxoid sarcoma (LGFMS) and sclerosing epithelioid fibrosarcoma (SEF) are two rare but aggressive soft tissue sarcomas that can be difficult to distinguish due to histopathological similarities. The present study examines the diagnostic capacities of mucin-4 (MUC4), a transmembrane mucin, in identifying different types of sarcomas and broadens its evaluation to include a wide range of sarcomas. Methods Immunohistochemical (IHC) examination of tissue samples from various sarcomas was performed using a mouse anti-MUC4 monoclonal antibody. IHC was conducted on 4-mm thick formalin-fixed paraffin-embedded tissue sections after pressure cooker antigen retrieval with a mouse anti-MUC4 monoclonal antibody. Results MUC4 was shown to be highly expressed in SEF (n=13) and LGFMS (n=10), while focal positivity in synovial sarcoma (n=1). Other sarcomas, such as malignant peripheral nerve sheath tumors, fibrosarcoma, leiomyosarcoma, liposarcoma, and myxofibrosarcoma, exhibited no expression (n=0). These findings are consistent with previous research and support MUC4 specificity as a SEF and LGFMS marker.This study provides information on the diagnostic efficacy of MUC4, particularly in the context of certain subtypes. It not only helps our understanding of these unique instances, but it also provides context for histopathological and IHC findings in soft tissue sarcoma. Furthermore, this study investigates the influence of age and gender on MUC4 expression in a range of sarcomas, which was typically understudied in the literature and found no relation with expression of MUC4. Conclusion In conclusion, this study adds to our understanding of soft tissue sarcomas by emphasizing the crucial role of MUC4 in certain sarcoma subtypes while acknowledging the complex variety of the sarcoma landscape. Further research is needed to understand the molecular mechanism that governs marker expression patterns, as well as the therapeutic implications.

Sclerosing Epithelioid Fibrosarcoma (SEF) versus Low Grade Fibromyxoid Sarcoma (LGFMS): Presentation and outcome in the nationwide NETSARC+ series of 330 patients over 13 years

Sclerosing Epithelioid Fibrosarcoma (SEF) and Low Grade Fibromyxoid Sarcoma (LGFMS) are ultrarare sarcomas sharing common translocations whose natural history are not well known. We report on the nationwide exhaustive series of 330 patients with SEF or LGFMS in NETSARC+ since 2010. Patients and methodsNETSARC (netsarc.org) is a network of 26 reference sarcoma centers with specialized multidisciplinary tumor boards (MDTB). Since 2010, (i) pathological review has been mandatory for sarcoma,and (ii) tumour/patients’ characteristics have been collected in the NETSARC+ nationwide database. The characteristics of patients with SEF and LGFMS and their outcome are compared. Results35/73 (48%) and 125/257(49%) of patients with SEF and LGFMS were female. More visceral, bone and trunk primary sites were observed in SEF (p < 0.001). 30% of SEF vs 4% of LGFMS patients had metastasis at diagnosis (p < 0.0001). Median size of the primary tumor was 51 mm (range 10–90) for LGFMS vs 80 (20−320) for SEF (p < 0.001). Median age for LGFMS patients was 12 years younger than that of SEF patients (43 [range 4–98] vs 55 [range 10–91], p < 0.001). Neoadjuvant treatment was more often given to SEF (16% vs 9%, p = 0.05). More patients with LGFMS were operated first in reference centers (51% vs 26%, p < 0.001). The R0 rate on the operative specimen was 41% in LGFMS vs 16% in SEF (p < 0.001). Median event-free survival (EFS) of patients with SEF and LGFMS were 32 vs 136 months (p < 0.0001). The median overall survival (OS) was not reached. Fifty-months OS was 93% vs 81% for LGFMS vs SEF (p = 0.05). Median OS was 77 months after first relapse, similar for SEF and LGFMS.In multivariate analysis, age, tumor size, metastasis at diagnosis were independent prognostic factors for OS in LGFMS. ConclusionsAlthough sharing close molecular alterations, SEF and LGFMS have a different natural history, clinical presentation and outcome, with a higher risk of metastatic relapse in SEF. Survival after relapse is longer than with other sarcomas, and similar for SEF and LGFMS.

CYP1A1 immunohistochemistry is highly specific for angiofibroma of soft tissue among morphological mimics.

Angiofibroma of soft tissue (AFST) is a benign, morphologically distinctive tumour type that harbours recurrent AHRR::NCOA2 fusions in 60-70% of cases and shows a non-specific immunophenotype, expressing EMA in roughly half of cases. The AHRR::NCOA2 fusion results in increased expression of cytochrome P450 1A1 (CYP1A1); a recent study demonstrated CYP1A1 immunohistochemistry (IHC) to be moderately sensitive and highly specific for AFST. In this study, we sought to validate these findings in a larger independent cohort of 30 AFST, as well as 215 morphological mimics, including 30 solitary fibrous tumours, 29 myxoid liposarcomas, 28 low-to-intermediate grade myxofibrosarcomas (MFS), 20 atypical spindle cell lipomatous tumours (ASCLT), 20 cellular angiofibromas, 10 cases each of spindle cell lipoma, neurofibroma, malignant peripheral nerve sheath tumour, superficial angiomyxoma, cellular myxoma, soft tissue perineurioma and deep fibrous histiocytoma, and nine cases each of low-grade fibromyxoid sarcoma and mammary-type myofibroblastoma. We found CYP1A1 IHC to be 70% sensitive for AFST, with granular cytoplasmic staining in 21 of 30 tumours, and 98% specific, with staining in only five morphological mimics: two deep fibrous histiocytomas, one MFS, one cellular angiofibroma and one ASCLT. These findings confirm that CYP1A1 is 70% sensitive, consistent with the prevalence of AHRR::NCOA2 fusions that up-regulate this protein, and that it is highly specific among morphological mimics.

1928P Differential presentation and outcome of sclerosing epithelioid fibrosarcoma (SEF) vs low grade fibromyxoid sarcoma (LGFMS): The nationwide series of 330 patients in NETSARC since 2010

1928P Differential presentation and outcome of sclerosing epithelioid fibrosarcoma (SEF) vs low grade fibromyxoid sarcoma (LGFMS): The nationwide series of 330 patients in NETSARC since 2010

FIBROMYXOID SARCOMA IN RATTUS NORVEGICUS: CASE REPORT

Myxoid sarcoma comprises malignant tumors of myxoid origin. Low-Grade Fibromyxoid Sarcoma (LGFM) has benign histopathological characteristics, slow growth, but with high metastatic potential. There are at least 25 cases of LGFM in humans, being more common in the deep intramuscular region, mainly in the thigh and trunk, but it has also been described in the retroperitoneum, mesentery and renal capsule. In December 2022, a 2-year-old male Wistar rat (Rattus norvegicus) had difficulty walking and a nodule was noted in the dorsal region of the left pelvic limb, measuring 2.5 cm x 3 cm. In January 2023, amputation was performed and the morphological diagnosis obtained was myxoid sarcoma. In February 2023, formation was observed in the left renal capsule measuring 2cm, growing to 6cm in May 2023, with the same diagnosis as that of the limb. The tutors opted for the surgical removal of the neoformation, however, the animal evolved to death, being referred for necroscopic examination. The case represents the first worldwide case of LGFM in Wistar, the second reported in animals.

FIBROMYXOID SARCOMA IN RATTUS NORVEGICUS: CASE REPORT

Myxoid sarcoma comprises malignant tumors of myxoid origin. Low-Grade Fibromyxoid Sarcoma (LGFM) has benign histopathological characteristics, slow growth, but with high metastatic potential. There are at least 25 cases of LGFM in humans, being more common in the deep intramuscular region, mainly in the thigh and trunk, but it has also been described in the retroperitoneum, mesentery and renal capsule. In December 2022, a 2-year-old male Wistar rat (Rattus norvegicus) had difficulty walking and a nodule was noted in the dorsal region of the left pelvic limb, measuring 2.5 cm x 3 cm. In January 2023, amputation was performed and the morphological diagnosis obtained was myxoid sarcoma. In February 2023, formation was observed in the left renal capsule measuring 2cm, growing to 6cm in May 2023, with the same diagnosis as that of the limb. The tutors opted for the surgical removal of the neoformation, however, the animal evolved to death, being referred for necroscopic examination. The case represents the first worldwide case of LGFM in Wistar, the second reported in animals.

Low grade fibromyxoid sarcoma of the oral cavity in an infant The youngest patient in the world A case report

Low grade fibromyxoid sarcoma LGFMS is a rare tumour in the head and neck. The literature reports less than 50 cases with different locations and variable ages from 22 months to 84 years.

Fibrosarcoma with deceptive benign presentations: a report of two cases.

Low-grade fibromyxoid sarcoma and myxofibrosarcoma are malignant soft tissue tumors, fibrosarcomas, of shared clinical and imaging appearances. We report sarcomatous lesions in soft tissue with deceptively benign clinical and imaging appearances, and correlate findings with those of histologic analysis. Two patients presented with a long history of painless swelling at the dorsum and upper extremity and denied any constitutional symptoms. Sonography and magnetic resonance imaging suggested the presence of benign soft tissue lesions of a predominant fluid-like consistency. Despite indolent clinical and imaging characteristics, in both cases, histopathology disclosed a diagnosis of spindle cell-type soft tissue sarcoma, designating an aggressive tumor. Knowledge of the seemingly benign clinical and imaging features of fibrosarcomas is required to raise the possibility of malignancy in soft tissue that may be underdiagnosed or misdiagnosed. The importance of a correct diagnosis and the implications of surgical resection, irradiation, and systemic oncological therapy are quite obvious.

Sclerosing epithelioid fibrosarcoma of bone with hybrid features: clinicopathologic, radiologic, and molecular analysis of three cases.

Sclerosing epithelioid fibrosarcoma (SEF) occurring as a primary bone tumor is exceptionally uncommon. Even more rare are cases of SEF that show morphologic overlap with low-grade fibromyxoid sarcoma (LGFMS). Such hybrid lesions arising within the bone have only rarely been reported in the literature. Due to their variegated histomorphology and non-specific radiologic features, these tumors maypose diagnostic difficulties. Herein we describe three molecularly confirmed primary bone cases of sclerosing epithelioid fibrosarcoma that demonstrated prominent areas showing the features of LGFMS and with areas resembling so-called hyalinizing spindle cell tumor with giant rosettes (HSCTGR). Two patients were female and one was male aged 26, 47, and 16, respectively. The tumors occurred in the femoral head, clavicle, and temporal bone. Imaging studies demonstrated relatively well-circumscribed radiolucent bone lesions with enhancement on MRI. Cortical breakthrough and soft tissue extension were present in one case. Histologically the tumors all demonstrated hyalinized areas with SEF-like morphology as well as spindled and myxoid areas with LGFMS-like morphology. Two cases demonstrated focal areas with rosette-like architecture as seen in HSCTGR. The tumors were all positive for MUC4 by immunohistochemistry and cytogenetics, fluorescence in-situ hybridization, and next-generation sequencing studies identified EWSR1 gene rearrangements confirming the diagnosis in all three cases.Hybrid SEF is exceedingly rare as a primary bone tumor and can be difficult to distinguish from other low-grade spindled and epithelioid lesions of bone. MUC4 positivity and identification of underlying EWSR1 gene rearrangements help support this diagnosis and exclude other tumor types.

A rare case report of pancreatic low-grade fibromyxoid sarcoma (LGFMS)

BackgroundLow-grade fibromyxoid sarcoma (LGFMS) is an uncommon neoplasm generally affecting muscle tissue. It presents rarely in abdominal viscera and even more rarely occurs in the pancreas. All types of pancreatic sarcomas are uncommon, and LGFMS is a rarer still. We present the case of an LGFMS in the pancreas. Because of its rarity, there are no guidelines for appropriate treatment or summations of the natural course of this illness.Case presentationWe present the case of a 49-year-old female who presented with epigastric pain. She had a prior history of three episodes of acute pancreatitis many years earlier. A CT revealed a pancreatic body mass, which was biopsied. Pathology returned LGFMS. The patient underwent a distal pancreatectomy and splenectomy. She did well after the case and did not require further intervention.ConclusionThough it is exceedingly rare, cases of pancreatic LGFMS should be reported in order to guide clinical decisions. LGFMS has been shown to have high malignant potential in other tissues, and there is no reason to think pancreatic masses will be different. By building a body of evidence about these rare tumors, patient care will benefit.

Low-grade fibromyxoid sarcoma of the breast: genetic characterization and immunohistochemical comparison to morphologic mimics

Spindle cell lesions of the breast elicit a specific, relatively limited differential diagnosis, and accurate classification often requires careful morphologic evaluation and immunohistochemical workup. Low-grade fibromyxoid sarcoma (LGFMS) is a rare malignant fibroblastic tumor with deceptively bland spindle cell morphology. Involvement of the breast is exceedingly rare. We examined the clinicopathologic and molecular characteristics of three cases of breast/axillary LGFMS. In addition, we interrogated the immunohistochemical expression of MUC4, a commonly used marker of LGFMS, in other breast spindle cell lesions. LGFMS presented in women at 23, 33, and 59 years of age. Tumor size ranged from 0.9 to 4.7 cm. Microscopically, they were circumscribed nodular masses composed of bland spindle cells with fibromyxoid stroma. Immunohistochemically, tumors were diffusely positive for MUC4 and negative for keratin, CD34, S100 protein, and nuclear beta-catenin. Fluorescence in-situ hybridization demonstrated FUS (n=2) or EWSR1 (n=1) rearrangements. Next-generation sequencing identified FUS::CREB3L2 and EWSR1::CREB3L1 fusions. MUC4 immunohistochemistry performed on 162 additional breast lesions demonstrated only weak and limited expression in a subset of cases of fibromatosis (10/20, ≤30% staining), scar (5/9, ≤10%), metaplastic carcinoma (4/23, ≤5%), and phyllodes tumor (3/74, ≤10%). MUC4 was entirely negative in cases of pseudoangiomatous stromal hyperplasia (n=9), myofibroblastoma (n=6), periductal stromal tumor (n=3), and cellular/juvenile fibroadenoma (n=21). LGFMS can rarely occur in the breast and should be considered in the differential diagnosis of breast spindle cell lesions. Strong and diffuse MUC4 expression is highly specific in this histologic context. Detection of an FUS or EWSR1 rearrangement can confirm the diagnosis.

Low-grade fibromyxoid sarcoma as a content of perineal hernia. A case report

Low-grade fibromyxoid sarcoma as a content of perineal hernia. A case report

Abstract #1400148: Anterior Cervical Liposarcoma Masquerading as a Thyroid Nodule

Primary sarcomas of the head and neck account for < 1% of tumors in this anatomic region. We present a case of a large anterior neck mass initially thought to originate from the thyroid gland but diagnosed as a cervical liposarcoma closely adjacent to the thyroid. A 64-year-old woman was referred for a right anterior neck mass that she first noticed about 6 weeks prior to evaluation. The patient reported mild degrees of dysphagia and dyspnea. Examination was notable for a large, painless, right anterolateral neck mass that was mobile on deglutition. Serum TSH level was unremarkable. Neck ultrasound revealed a well circumscribed 6.0 x 3.7 x 5.4 cm isoechoic mass that appeared to largely replace the right thyroid lobe. Fine needle biopsy yielded a specimen composed only of peripheral blood elements. Computed tomography of the neck revealed a 9.1 x 6.2 x 6.0 cm hypodense (- 4 Hounsfield units) mass originating in the right carotid space and displacing the trachea, larynx, and esophagus to the left of midline, the right sternocleidomastoid muscle anteriorly, and the right carotid artery and jugular vein laterally. Cytology on a core biopsy was notable for a pleomorphic spindle cell neoplasm with lipoid differentiation and positive staining for CD34 and vimentin felt to be consistent with a liposarcoma. The mass was removed during a right modified radical neck dissection, and postsurgical histopathology revealed an encapsulated tumor with negative surgical margins and MDM2 amplification by fluorescent in situ hybridization (FISH), making the final diagnosis a well-differentiated liposarcoma. Neck masses adjacent to the thyroid may appear to arise from thyroid parenchyma. Several tumors, including paragangliomas, very large parathyroid tumors, lipomas, and a case of low-grade fibromyxoid sarcoma are reported as mimicking thyroid nodules on initial evaluation. There is limited literature on liposarcomas of the head and neck, with 30 patients seen at M.D. Anderson from 1945-2005 the largest published case series. Well-differentiated liposarcomas accounted for approximately 25% (7/30) of cases, and painless neck mass as in this case was the most common presenting symptom. No patients with well-differentiated extrathyroidal liposarcomas died of their tumors in the M.D. Anderson series, in contrast to a tumor-related mortality rate of approximately 30% in the rare (N=13) cases of liposarcoma arising from the thyroid. A PubMed search failed to reveal any cases of liposarcoma mimicking a thyroid nodule. This case illustrates that large anterior neck masses require careful imaging evaluation to confirm apparent origin from the thyroid gland.

Challenging Diagnosis of Low-grade Fibromyxoid Sarcoma of the Chest Wall: Case Report

Introduction: Low-grade fibromyxoid sarcoma (LGFMS) is a rare special subtype of fibrosarcoma, it is more common in the trunk and proximal limbs. First described by Evans in 1987, this tumor is also named Evans tumor. Diagnosis of LGFMS may be quite challenging, either due to the low suspicion rate of the tumor or low specificity of its morphological pattern and immunohistochemical profile, a phenomenon that is magnified when tumor location is less usual, such as in the chest wall. The present article presents a challenging case of LGFMS of the chest wall. Case report: Female, 58-year-old patient was referred to the oncology referral clinic with a breast tumor. Diagnostic investigation included imaging tests (breast US and chest CT scan) and core needle biopsy. CT scan revealed the epicenter of the tumor in the left anterior thoracic wall. Biopsy to evaluate the histologic type of tumor was carried out and the result was inconclusive. Therefore, surgical excision of the tumor was performed. Histopathology and immunohistochemistry studies of the surgical specimen confirmed the diagnosis of LGFMS of the chest wall. Currently, after 36 months of the surgical excision, the patient is still doing well and continues under clinical follow-up. Conclusion: Although the diagnosis of LGFMS of the chest wall is challenging, it should be done correctly, since these cases require a long and thorough clinical follow-up.