EMA-Positive Superficial ALK-Rearranged Myxoid Spindle Cell Neoplasm Masquerading as Perineurioma/Hybrid Nerve Sheath Tumor.

ABSTRACT: Superficial anaplastic lymphoma kinase (ALK)-rearranged myxoid spindle cell neoplasm (SAMS) is a recently described entity which coexpresses ALK, CD34, and commonly S100. These neoplasms are characterized morphologically by concentric spindle cell whorls and cords and are commonly set in an abundant myxoid to myxocollagenous stroma, thus mimicking perineurioma or hybrid nerve sheath tumor. EMA immunostain has been reported to be negative in SAMS which helps in excluding the latter entities. Herein, we report the first EMA-positive SAMS of the right leg in a 37-year-old female patient masquerading as perineurioma/hybrid nerve sheath tumor. The tumor morphologically was comprised of spindle cells arranged in loose whorls and short fascicles set in myxoid to collagenous stroma and coexpressed CD34 and EMA, reminiscent of perineurioma. S100 showed focal staining. ALK immunostain was subsequently performed and was positive. ALK gene rearrangement was identified by fluorescence in situ hybridization break-apart assay and was further confirmed by next-generation sequencing-based RNA sequencing demonstrating FLNA::ALK fusion, thus supporting the diagnosis of SAMS. In conclusion, EMA can be expressed in SAMS, thus posing as a diagnostic pitfall. ALK immunostain and molecular studies are essential for confirming the diagnosis of SAMS and excluding potential mimickers, particularly perineurioma or hybrid nerve sheath tumor.

Elastofibroma Dorsi: experience of a single center.

OBJECTIVE: Elastofibroma dorsi (ED) is a rare benign tumor located in the subscapular region. The aim of this study was to evaluate our clinical findings, surgical approach, and management of ED patients based on single-center data with the relevant literature. METHODOLOGY: A retrospective evaluation was conducted on 20 patients who were operated on for ED. RESULTS: Of the 16 (80%) female patients and 4 (20%) male patients, the main complaint was swelling (80%), and 10 cases (50%) had unilateral involvement. All patients were operated on using standard surgical procedures. Despite a long follow-up period (6-53 months, mean of 26.6 months), no recurrences were observed. Two patients (10%) required simple needle aspiration due to post-operative seroma, and one patient, due to infection, required evacuation (5%). CONCLUSION: Although rare, ED should not be overlooked in patients with swelling in the back region. Our data suggests that surgery can be safely performed in such patients after a clinical and radiological diagnosis of ED has been established.

OBJETIVO: Evaluar los hallazgos clínicos, el enfoque quirúrgico y el manejo de los pacientes con urgencias a partir de los datos de un solo centro y la literatura relevante. MÉTODO: Se realizó una evaluación retrospectiva de 20 pacientes que fueron operados de ED. RESULTADOS: En los 16 (80%), pacientes del sexo femenino y cuatro (20%) del sexo masculino, la queja principal fue la tumefacción (80%) y 10 casos (50%) tuvieron afectación unilateral. Todos los pacientes fueron operados utilizando procedimientos quirúrgicos estándar. Con un largo periodo de seguimiento (6-53 meses, media de 26.6 meses), no se observaron recurrencias. Dos pacientes (10%) requirieron aspiración con aguja simple por seroma posoperatorio y un paciente (5%) requirió evacuación por infección. CONCLUSIONES: Aunque es raro, el ED no debe pasarse por alto en pacientes con hinchazón en la región de la espalda. Nuestros datos sugieren que la cirugía se puede realizar de manera segura en estos pacientes después de haber establecido el diagnóstico clínico y radiológico de ED.

Keratin-Positive Giant Cell Tumor of Bone and Soft Tissue With HMGA2::NCOR2 Fusion in Children Under 10 With Response to Imatinib Therapy: A Case Series.

HMGA2::NCOR2 keratin-positive giant cell tumors in children with response to imatinib in an infant.

Outcomes of non-angiosarcoma radiation-associated soft tissue sarcomas of the chest.

BACKGROUND: Radiation-associated soft tissue sarcomas (RA-STS) are rare complications of patients receiving radiation therapy (RT) and are generally associated with a poor prognosis. Most of the literature surrounding RA-STS of the chest is centered on angiosarcoma. Therefore, we aim to document the management and outcome of patients with non-angiosarcoma RA-STS of the chest. METHODS: We reviewed 17 patients (all female, median age 65 years) diagnosed with RA-STS. The most common primary malignancy was breast carcinoma (n = 15), with a median RT dose of 57.9 Gy. All patients underwent surgical resection; five patients (29%) received radiotherapy; and five patients (29%) received peri-operative chemotherapy. RESULTS: The 5-year local recurrence and metastatic-free survival were 61% and 60%, while the 5-year disease-specific survival was 53%. Local recurrence was associated with death due to disease (HR 9.06, p = 0.01). Complications occurred in nine of patients, most commonly due to a wound complication (n = 7). At the most recent follow-up, the median Musculoskeletal Tumor Society Score was 63%. CONCLUSION: RA-STS involving the chest wall are aggressive tumors with a high risk of local relapse and death due to disease. Local recurrence was associated with death due to disease; as such, we recommend aggressive surgical management with evaluation for adjuvant therapies.

Tumoración en dorso de mano: a propósito de un caso / Tumor on the back of the hand: about a case

Spinocellular carcinoma is a tumor lesion that frequently occurs in photo-exposed areas, presenting characteristics such as keratinization, scaly areas and even ulcerations. Its potential for metastasis makes early identification and diagnosis essential in order to carry out correct treatment of said lesion. In the spectrum of spinocelullar carcinomas is Keratoacanthoma, which has been in debate about its origin and its benignity. We present the clinical evolution, treatment, results, and bibliographic review of a keratoacanthoma.

El carcinoma espinocelular es una lesión tumoral que se da frecuentemente en zonas foto-expuestas, presentando características tales como queratinización, zonas descamativas e incluso ulceraciones. Su potencial de metástasis hace imprescindible la identificación y diagnóstico precoz para poder realizar un correcto tratamiento de dicha lesión. Dentro de su espectro se encuentra el Queratoacantoma, el cual ha estado en debate sobre su origen y su benignidad. Nosotros presentamos la evolución clínica, tratamiento, resultados y revisión bibliográfica de un queratoacantoma.

Prognostic Factors Associated with Tumor Recurrence and Overall Survival in Soft Tissue Sarcomas of the Extremities in a Colombian Reference Cancer Center.

Introduction: Soft tissue sarcomas (STS) are low-incidence tumors whose clinical and histopathological factors are associated with adverse oncological outcomes. This study evaluated prognostic factors (PF) associated with tumor recurrence and overall survival (OS) in patients diagnosed with STS of the extremities, treated at the Instituto Nacional de Cancerología (INC), Bogotá, Colombia. Materials and Methods: An analytical observational study of a historical cohort was carried out, including patients diagnosed with STS and managed surgically in the Functional Unit for Breast and Soft Tissue Tumors of the INC from January 2008 to December 2018. Results: A total of 227 patients were included; 74.5% had tumors greater than 5 cm. Most patients (29.1%) were in stage IIIB at diagnosis. Age was associated with higher mortality (HR = 1.01; CI95%: 1-1.02; p = 0.048). Tumor persistence at admission to the INC (HR = 2.34; CI95%: 1.25-4.35; p = 0.007) and histologic grade III (HR = 5.36; CI95%: 2.29-12.56; p = <0.001) showed statistical significance in the multivariate analysis for recurrence of any type, as did the PFs associated with a higher risk of local recurrence (HR = 2.85; CI95%: 1.23-6.57; p = 0.014 and HR = 6.09; CI95%: 2.03-18.2; p = 0.001), respectively. Tumor size (HR = 1.03; CI95%: 1-1.06; p = 0.015) and histologic grade III (HR = 4.53; CI95%: 1.42-14.49; p = 0.011) were associated with a higher risk of distant recurrence. Conclusions: This cohort showed that in addition to histologic grade and tumor size, tumor persistence at the time of admission has an impact on disease recurrence, so STS should be managed by a multidisciplinary team with experience in this pathology in high-volume reference centers.

Wound healing outcomes following treatment with synthetic hybrid-scale fiber matrix after resection of soft tissue tumors or infections.

BACKGROUND: Wide excision of soft tissue tumors or infections often results in large defects that can be challenging to manage. Advanced treatment modalities-including NPWT, skin grafts, and xenografts-can all be considered for post-resection wound management, but each has its limitations. An SHSFM, engineered to resemble human extracellular matrix, has demonstrated positive wound healing outcomes in prior studies. MATERIALS AND METHODS: Adult patients at a single institution who underwent resection of soft tissue tumor or infected tissue followed by treatment with SHSFM from 2020-2023 were retrospectively reviewed. RESULTS: Ten patients were included in the review after meeting the inclusion criteria. Overall, 7 of 10 wounds had documented complete closure, with 3 lost to follow-up. Average time to wound closure was 119 days. Patients either healed via secondary intention or were bridged to a split-thickness skin graft. The average VSS score was 3.3 when assessed. CONCLUSION: The current case series demonstrated that the SHSFM can support granulation tissue formation over exposed structures as a bridge to skin graft or can completely reepithelialize large wounds without skin grafting. The SHSFM offers a novel treatment option for post-resection surgical wounds.

Anaplastic large cell lymphoma with ALK::ATIC fusion mimicking a histiocytic sarcoma debuting as an anterior thoracic soft tissue tumor with exceptional clinicopathological, morphological and molecular features.

A 56-year-old woman debuted with a palpable painless mass in the anterior thorax wall at the level of the second and third right parasternal intercostal space, which progressively increased in size over 5 months accompanied by localized skin rash, mild dyspnea and chest pain when changing position. Imaging studies showed a soft tissue mass measuring 75 × 62 mm and a density of 34 Hounsfield Units that had caused the lysis of the costal arches and grew expansively towards the anterior mediastinum, without identifying mediastinal adenopathies only by this imaging method. Core biopsy was performed, which was initially diagnosed as histiocytic sarcoma (HS); however, when the diagnostic panel was expanded to include molecular and NGS studies, the final diagnosis was anaplastic large cell lymphoma with ALK::ATIC fusion. Here, we report a very rare neoplasm with unusual clinical presentation, histopathology and molecular features.

Tumor metastásico en tejido blando a nivel del sacro secundario a carcinoma de células claras de riñón. Reporte de caso / Metastatic tumor in soft tissue at the level of the sacrum secondary toclear cell carcinoma of the kidney. A case report

Introducción. El cáncer de riñón es la undécima neoplasia maligna más común en los Estados Unidos Mexicanos. El carcinoma de células claras de riñón (CCR) es considerado la estirpe más frecuente y representa el 2-3 % de todos los cánceres a nivel mundial. En el contexto de la enfermedad metastásica, por lo general se identifica un tumor renal primario y las metástasis se localizan en pulmón, hueso, hígado, cerebro y, raramente, en tejidos blandos. Los pacientes con metástasis a tejidos blandos no tienen síntomas en las etapas iniciales y generalmente se identifican sólo cuando las lesiones aumentan de tamaño o durante el estudio de la pieza de resección quirúrgica. Caso clínico. Se presenta el caso de una paciente en la séptima década de la vida, con una metástasis en tejidos blandos de la región sacra, de 10 años de evolución posterior a una nefrectomía secundario a CCR. Resultados. Hallazgos clínicos e imagenológicos de un tumor bien delimitado. Se realizó resección quirúrgica de la lesión, bajo anestesia regional, con extirpación completa. Conclusión. Se recomienda que los pacientes con un sitio metastásico resecable y solitario sean llevados a resección quirúrgica con márgenes libres, como fue el caso de nuestra paciente, por su fácil acceso y ser una lesión única. En el CCR, además de su tratamiento quirúrgico inicial, es indispensable una estrecha vigilancia con examen físico e imágenes transversales, para detectar la presencia de metástasis y con ello evitar tratamientos tardíos.

Introduction. Kidney cancer is the eleventh most common malignancy in the United States of Mexico. Carcinoma renal cell (CRC) is considered the most frequent type and represents 2-3% of all cancers worldwide. In the setting of metastatic disease, a primary renal tumor is usually identified, and metastases are located in the lung, bone, liver, brain, and rarely in soft tissue. Patients with soft tissue metastases do not have symptoms in the initial stages and are generally found only when the lesions increase in size or during the study of the surgical resection piece. Clinical case. In this case, we report a female patient in the seventh decade of life with a soft tissue metastasis located in the sacral region, 10 years after a nephrectomy secondary to CRC. Results. Clinical and radiological findings of a well-defined tumor. Surgical resection of the lesion is performed under regional anesthesia with complete excision. Conclusions. It is recommended that patients with a resectable and solitary metastatic site be candidates for surgical resection with free margins, as was the case with our patient due to its easy access and single lesion. In CRC, in addition to its initial surgical treatment, close surveillance with physical examination and cross-sectional images is essential to monitor the presence of metastases and thus avoid late treatments.

Molecular Tumor Board Improves Outcomes for Hispanic Patients With Advanced Solid Tumors.

PURPOSE: Multidisciplinary molecular tumor boards (MTBs) decode complex genomic data into clinical recommendations. Although MTBs are well-established in the oncology practice in developed countries, this strategy needs to be better explored in developing countries. Herein, we describe the possible benefits and limitations of the first MTB established in Colombia. METHODS: Demographic, clinical, and genomic information was collected between August 2020 and November 2021. By mid-2020, an MTB strategy was created to discuss clinical cases with one or more genomic alterations identified by next-generation sequencing using an open-access virtual platform. We characterized the patient population as benefiting from the recommended treatment option. We assessed the benefits and access to available targeted therapies that have the potential to change clinical management by making recommendations to treating oncologists on the basis of genomic profiling. However, we did not assess the treatment oncologists' compliance with MTB recommendations because they were not intended to replace clinical judgment/standard of care. RESULTS: A total of 146 patients were included in the discussions of the MTB. The median age was 59 years, and 59.6% were women. Genomic results prompting a change in therapeutic decisions were obtained in 53.1% of patients (95% CI, 44.9 to 61.3). The most prevalent malignancy was non-small-cell lung cancer (51%). Other malignancies represented 60%, 50%, and 30% of patients with soft-tissue sarcomas, brain tumors, and breast cancer, respectively. CONCLUSION: Using an open-access virtual platform, MTBs were feasible in low- and middle-income countries on the basis of the capability to provide the benefits and access to available targeted therapies that are not standard of care. Furthermore, MTB recommendations were made available to the treating oncologist in different locations across Colombia, providing the option to modify clinical management in most of these patients.

Moderate hypofractionated radiation therapy and pathologic response for soft tissue sarcomas (STS) of limbs and trunk: experience from a tertiary cancer center.

BACKGROUND: Preoperative radiation therapy following by limb-sparing or conservative surgery is a standard approach for limb and trunk STS. Data supporting hypofractionated radiotherapy schedules are scarce albeit biological sensitivity of STS to radiation would justify it. We sought to evaluate the impact of moderate hypofractionation on pathologic response and its influence on oncologic outcomes. MATERIAL AND METHODS: From October 2018 to January 2023, 18 patients with limb or trunk STS underwent preoperative radiotherapy at a median dose of 52.5 Gy (range 49.5-60 Gy) in 15 fractions of 3.5 Gy (3.3-4 Gy) with or without neoadjuvant chemotherapy. A favorable pathologic response (fPR) was considered as ≥ 90% tumor necrosis on specimen examination. RESULTS: All patients completed planned preoperative radiotherapy. Eleven patients (61.1%) achieved a fPR, and 7 patients (36.8%) a complete pathologic response with total disappearance of tumor cells. Nine patients (47%) developed grade 1-2 acute skin toxicity, and 7 patients (38.8%) had wound complications on follow-up. With a median follow-up of 14 months (range 1-40), no cases of local relapse were observed, and actuarial 3-year overall survival (OS) and distant metastases-free survival (DMFS) are 87% and 76.4%, respectively. In the univariate analysis, the presence of a favorable pathologic response (fPR) was associated with improved 3-year OS (100% vs. 56.03%, p = 0.058) and 3-year DMFS (86.91% vs. 31.46%, p = 0.002). Moreover, both complete or partial RECIST response and radiological stabilization of the tumor lesion showed a significant association with higher rates of 3-year distant metastasis-free survival (DMFS) (83% vs. 83% vs. 56%, p < 0.001) and 3-year overall survival (OS) (100% vs. 80% vs. 0, p = 0.002). CONCLUSIONS: Preoperative moderate hypofractionated radiation treatment for STS is feasible and well tolerated and associates encouraging rates of pathologic response that could have a favorable impact on final outcomes.

Uterine Sarcoma With EML4::NTRK3 Fusion: A Spectrum of Mesenchymal Neoplasms Harboring Actionable Gene Fusions.

NTRK gene fusions are part of a paradigm shift in oncology, arising as one of the main genomic alterations with actionability in the so-called "agnostic setting." In gynecologic pathology, the recent description of uterine sarcoma resembling fibrosarcoma and with NTRK rearrangements ( NTRK -rearranged uterine sarcoma) highlights the importance of recognizing clinicopathological cues that can lead to genomic profiling. Herein, we report the case of a 43-year-old woman presenting with vaginal bleeding and pelvic mass. Histopathology of the tumor showed moderately atypical spindle cells arranged in long fascicles reminiscent of fibrosarcoma, along with immunohistochemical positivity for S100, CD34, and pan-tropomyosin receptor kinase. This prompted RNA-sequencing and the finding of a rare EML4::NTRK3 fusion. Clinical, histologic, and molecular findings are described, in addition to discussions regarding differential diagnoses and possible implications of the findings in clinical practice.

Sensory and Motor Median Nerve Neuropathy Due to a Deep Giant Hand Lipoma: A Case Report / Neuropatia sensorial e motora do nervo mediano por um lipoma gigante na mão: Relato de caso

Abstract Lipomas are the most common soft-tissue tumors in the human body, but their location in the hand is rare. Symptomatic hand lipomas, due to nerve compression, are even rarer. We present a case of median nerve neuropathy as a result of a giant palm lipoma, located on the thenar and hypothenar areas of the hand. The patient had typical symptoms of carpal tunnel syndrome, along with compromised thumb motion. Intraoperatively, the recurrent motor branch of the median nerve was sitting on the lipoma under a great tension. This particular location of the motor branch of the median nerve in relation to the lipoma makes this case unique. The tumor was excised protecting the neurovascular structures, and a few weeks later the patient regained full thumb motion, grip strength, and resolution of dysesthesia.

Resumo Os lipomas são os tumores de partes moles mais comuns no corpo humano, mas sua localização na mão é rara. Os lipomas de mão que causam sintomas por compressão do nervo são ainda mais raros. Apresentamos um caso de neuropatia do nervo mediano decorrente de um lipoma palmar gigante, localizado nas regiões tenar e hipotenar da mão. A paciente apresentava sintomas típicos de síndrome do túnel do carpo, além de comprometimento dos movimentos do polegar. Durante a cirurgia, o ramo motor recorrente do nervo mediano repousava sobre o lipoma sob grande tensão. Esta localização particular do ramo motor do nervo mediano em relação ao lipoma torna este caso único. O tumor foi extirpado, protegendo as estruturas neurovasculares e, poucas semanas depois, a paciente havia recuperado totalmente os movimentos do polegar e força de preensão, além de apresentar resolução da disestesia.

Pseudotumor fibroso calcificante de cuello en una paciente adolescente: reporte de caso / Calcifying fibrous pseudotumor of the neck in an teenager female patient: case report

RESUMEN: Introducción: El pseudotumor fibroso calcificante es un tumor benigno de tejidos blandos que aparece principalmente en niños y adultos jóvenes entre 20 y 30 años de edad, aún sin una etiología clara y definida. De distribución corporal variable, siendo relativamente poco común en el cuello. Caso clínico: Se presenta el caso de una paciente adolescente de 17 años con tumor en el cuello de rápido crecimiento que se manifestó con dolor moderado localizado, ronquido excesivo y dificultad respiratoria progresiva. Tratamiento: Se realiza resección completa del tumor localizado en hipofaringe, la cual confirma el diagnóstico histopatológico e inmunohistoquímico de pseudotumor fibroso calcificante. Conclusión: El pseudotumor fibroso calcificante de cuello es una patología benigna rara, con síntomas inespecíficos y muy probablemente, inducida porque el tumor comprime los tejidos circundantes. La resolución quirúrgica sigue siendo el Gold estándar (GS) en cuanto al tratamiento. El pronóstico postresección es bueno a largo plazo, con tasas bajas de recurrencias. Se discute la aproximación diagnóstica y terapéutica en un paciente adolescente comparado con lo descrito en la literatura.

ABSTRACT Introduction: Calcifying fibrous pseudotumor is a benign soft tissue tumor, appearing mainly in children and young adults between 20 and 30 years of age, still without a clear and defined etiology. It has a variable body distribution, being relatively uncommon in the neck. Case report: We present the case of a 17-year-old teenager female patient with a rapidly growing neck tumor, which manifested with moderate localized pain, excessive snoring and progressive respiratory distress. Treatment: Complete resection of the tumor located in the hypopharynx was performed, which confirmed the histopathological and immunohistochemical diagnosis of calcifying fibrous pseudotumor. Conclusion: Calcifying fibrous pseudotumor of the neck is a benign pathology, rare with non-specific symptoms and most probably induced by the tumor compressing the surrounding tissues. Surgical resolution remains the gold standard for treatment. The prognosis after resection is good in the long term, with low recurrence rates. The diagnostic and therapeutic approach in this teenager patient is discussed compared to that described in the literature

225Ac-iPSMA-RGD for Alpha-Therapy Dual Targeting of Stromal/Tumor Cell PSMA and Integrins.

Prostate-specific membrane antigens (PSMAs) are frequently overexpressed in both tumor stromal endothelial cells and malignant cells (stromal/tumor cells) of various cancers. The RGD (Arg-Gly-Asp) peptide sequence can specifically detect integrins involved in tumor angiogenesis. This study aimed to preclinically evaluate the cytotoxicity, biokinetics, dosimetry, and therapeutic efficacy of 225Ac-iPSMA-RGD to determine its potential as an improved radiopharmaceutical for alpha therapy compared with the 225Ac-iPSMA and 225Ac-RGD monomers. HEHA-HYNIC-iPSMA-RGD (iPSMA-RGD) was synthesized and characterized by FT-IR, UV-vis, and UPLC mass spectroscopy. The cytotoxicity of 225Ac-iPSMA-RGD was assessed in HCT116 colorectal cancer cells. Biodistribution, biokinetics, and therapeutic efficacy were evaluated in nude mice with induced HCT116 tumors. In vitro results showed increased DNA double-strand breaks through ROS generation, cell apoptosis, and death in HCT116 cells treated with 225Ac-iPSMA-RGD. The results also demonstrated in vivo cytotoxicity in cancer cells after treatment with 225Ac-iPSMA-RGD and biokinetic and dosimetric properties suitable for alpha therapy, delivering ablative radiation doses up to 237 Gy/3.7 kBq to HCT116 tumors in mice. Given the phenotype of HCT116 cancer cells, the results of this study warrant further dosimetric and clinical studies to determine the potential of 225Ac-iPSMA-RGD in the treatment of colorectal cancer.

Neuroblastoma with superficial soft tissue mass as the first symptom: case reports with atypical ultrasonic image and literature review.

Neuroblastoma is one of the most common tumors in children. Cases where an isolated soft-tissue metastasis mass is the initial symptom are rare, with only four such cases reported to date. We describe the imaging findings of ten cases of neuroblastoma patients in our hospital with superficial soft tissue mass (SSTM) as the primary symptom. The main ultrasound finding of SSTM was hypoechoic masses or scattered speck-like hyperechoic masses. However, when this type of SSTM is caused by soft tissue metastasis, the location is often atypical, and ultrasound findings are difficult to distinguish from other benign diseases. Therefore, this research should remind clinicians to recognize atypical presentations of this common childhood malignant tumor. Radiologists should also consider the possibility of neuroblastoma when finding this type of SSTM with atypical ultrasound features.

Localización atípica de un lipoblastoma en una niña de 5 años / Atypical location of lipoblastoma in a 5-year-old girl

Se informa de un lipoblastoma perineal en una niña de 5 años localizado en el labio mayor derecho. La lesión aumentó gradualmente en 6 meses. En la ecografía y la resonancia magnética (RM), se observó un tumor heterogéneo sólido limitado con componente graso. Tras su extirpación quirúrgica, el estudio anatomopatológico confirmó un lipoblastoma. El lipoblastoma es un tumor mesenquimatoso benigno poco frecuente de la lactancia y la primera infancia. Los síntomas varían en función de la localización; pueden observarse signos de compresión de los órganos adyacentes. Este tipo de tumores inusuales de los tejidos blandos son más frecuentes en menores de 3 años. Los lipoblastomas se localizan predominantemente en las extremidades, pero también pueden encontrarse en la cabeza y el cuello, el tronco, el mediastino, el riñón, el mesenterio, el retroperitoneo y el perineo. Se debe sospechar su presencia en función de los hallazgos de la ecografía y la RM.

We reported a perineal lipoblastoma in a 5-year-old girl located in the right labia mayor. The lesion gradually increased within 6 months. Ultrasound and magnetic resonance imaging (MRI) showed a limited solid heterogenous tumor with fatty component. After it had been surgically removed, the anatomopathological examination confirmed that it was a lipoblastoma. Lipoblastoma is a rare benign mesenchymal tumor of infancy and early childhood. Symptoms vary depending on localization; signs of compression of adjacent organs may be seen. This type of unusual soft tissue tumors occurred most often in under 3 years old. The localization of lipoblastomas is predominantly in the extremities but may be also found in other sites including the head and neck, trunk, mediastinum, kidney, mesentery, retropritoneum and perineum. The suspicion should be considered according to ultrasound and MRI findings.

Primary Orbital Myxoid Liposarcoma.

Although liposarcoma is the most prevalent soft tissue sarcoma in adults, head and neck liposarcomas are rare and account for less than 5% of all liposarcomas. The primary orbital location is even more exceptional, with fewer than 100 cases documented in the medical literature. Given the scarcity of cases of orbital liposarcoma and the limited familiarity of physicians and pathologists with this pathology, there is an increased risk of non-diagnosis or misdiagnosis, which may lead to inappropriate patient management. To address these challenges, we present a case of primary orbital myxoid liposarcoma and subsequently discuss the primary findings of this case based on the evidence documented in the medical literature. This comprehensive text is designed to serve as a valuable resource for healthcare professionals and pathologists, with the goal of promoting both clinical suspicion and accurate diagnosis and treatment of this rare condition in future cases.