Dendritic fibromyxolipoma with intramuscular involvement: A case mimicking slow flow vascular malformation on imaging.

Dendritic fibromyxolipoma (DFML) is a benign, very rare, and slow-growing soft tissue tumor commonly involving the muscular fascia of the foot, calf, shoulders, back, or head and neck muscles. Many authors consider dendritic fibromyxolipoma a variant of spindle cell lipoma composed of a plexiform vascular pattern, dendritic cytoplasmic processes, and keloidal collagen. Only a few cases have been reported in the shoulder region, and the presented case represents the second case in English literature whose histopathology showed intramuscular involvement. Recognition of such an entity is essential because it is considered a scarce type of benign tumor that can be mistaken for other aggressive neoplasms of myxoid pathology. We present a case of a dendritic fibromyxolipoma around the right shoulder with intramuscular involvement to the superficial fibers of the right trapezius muscle.

Expanding the Spectrum of EWSR1::CREM Fusion Tumors: An Unusual Pediatric Intranasal Myxoid Tumor.

EWSR1::CREM gene fusions are increasingly being recognized in a diverse number of soft tissue tumors, including well-defined entities such as angiomatoid fibrous histiocytoma or clear cell sarcoma, and other unclassifiable tumors. As a group, EWSR1::CREM fused tumors often demonstrate primitive spindle or epithelioid cells, myxoid stroma, and a broad immunophenotype. Herein we present an unusual case of a child diagnosed with an intranasal malignant myxoid tumor harboring an EWSR1::CREM gene fusion. To the best of our knowledge, this is the first case of intranasal myxoid tumor with this particular fusion. Diagnosis and management of the case is discussed.

Common Tumor in an uncommon location: Pleomorphic Adenoma of nasal cavity - a case Report.

Pleomorphic adenoma (PA) is the most common benign salivary gland tumor of which parotid gland involvement is the most common. PA may arise from minor salivary glands as well, however, PA is very rare in the sinonasal and nasopharyngeal areas. It usually affects middle aged females. They are frequently misdiagnosed due to high cellularity and myxoid stroma, leading to delay in diagnosis & further appropriate management. Here we present a case report of a female who presented with gradually progressive nasal obstruction, on examination found to have a nasal mass in right nasal cavity. Imaging was done and the nasal mass was excised. Histopathological report revealed a PA. Common tumor in an uncommon location: Pleomorphic adenoma of the nasal cavity - a case report.

A case of acral fibrochondromyxoid tumor / 中华皮肤科杂志

A 44-year-old male patient presented with a subcutaneous nodule in the left little finger for 3 years. Skin examination showed a subcutaneous nodule with rubber-like hardness but no tenderness on palpation, measuring 0.4 cm × 0.4 cm in size at the dorsal distal aspect of the left little finger, and the movement of the distal interphalangeal joint was unrestricted. Postoperative histopathological examination revealed that the tumor contained abundant stroma consisting of variable fiberous, chondroid and myxoid materials; tumor cells were oval to short spindle-shaped with inconspicuous nucleoli but no mitosis; cells were arranged haphazardly or in small clusters. Immunohistochemical study showed positive staining for vimentin, CD34 and transcription factors ERG and SOX9, but negative staining for S100, P63, broad-spectrum cytokeratin AE1/AE3, epithelial membrane antigen, smooth muscle actin and desmin in tumor cells, and the Ki67 labeling index was below 1%. Finally, the patient was diagnosed with acral fibrochondromyxoid tumor.

Conjunctival myxoma: A systematic review of a rare tumor.

Conjunctival myxoma is an uncommon benign tumor that may develop as a localized disease or as part of the Carney complex, in which case it can cause significant morbidity and mortality. Conjunctival myxomas can mimic other pure or mixed tumors and are often overlooked in clinical practice. Histopathological studies are essential for diagnosis; however, controversy regarding their pathological and immunohistochemical features makes the diagnostic process more difficult. Because of the importance of correctly classifying these conjunctival tumors, as well as recognizing when a systematic screening is required owing to the possible association with life-threatening diseases, we comprehensively evaluate the literature on this rare entity based on a systematic approach.

Low-grade fibromyxoid sarcoma: A rare case report.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare type of sarcoma that is characterized by benign-appearing histologic features but a paradoxically aggressive clinical course. Recognition of this lesion is important because of its indolent but metastasizing nature. These tumors generally occur in young to middle-aged adults, sometimes in children, but rarely in the high-aged adults. LGFMS typically affects the deep soft tissues of the trunk or lower extremities: however, it is rarely seen on the maxillofacial region. Here, we describe a case of LGFMS on the left lower one-third region of the face of a 35-year-old male patient with a 6-month history. On gross examination, the resected specimen consisted of an open ovoid mass of 2 cm × 2 cm × 1 cm. Light microscopy revealed well-circumscribed myxoid tumor with hypocellular areas in nodules merging to collagenized areas. Immunohistochemical examination revealed diffuse positivity to vimentin, whereas tests for desmin, S-100 protein were negative, thus confirming the diagnosis. After the initial healing of the surgical wound, the patient was advised 30 cycles of radiotherapy. Recurrence and metastasis have not been observed for 1 year of surgical excision now. Due to the notably indolent nature of LGFMS, long-term follow-up is necessary to evaluate its clinical course.

Desmoplastic myxoid tumor of pineal region, SMARCB1-mutant, in young adult.

We present a young adult woman who developed a myxoid tumor of the pineal region having a SMARCB1 mutation, which was phenotypically similar to the recently described desmoplastic myxoid, SMARCB1-mutant tumor of the pineal region (DMT-SMARCB1). The 24-year-old woman presented with headaches, nausea, and emesis. Neuroimaging identified a hypodense lesion in CT scans that was T1-hypointense, hyperintense in both T2-weighted and FLAIR MRI scans, and displayed gadolinium enhancement. The resected tumor had an abundant, Alcian-blue positive myxoid matrix with interspersed, non-neoplastic neuropil-glial-vascular elements. It immunoreacted with CD34 and individual cells for EMA. Immunohistochemistry revealed loss of nuclear INI1 expression by the myxoid component but its retention in the vascular elements. Molecular analyses identified a SMARCB1 deletion and DNA methylation studies showed that this tumor grouped together with the recently described DMT-SMARCB1. A cerebrospinal fluid cytologic preparation had several cells morphologically similar to those in routine and electron microscopy. We briefly discuss the correlation of the pathology with the radiology and how this tumor compares with other SMARCB1-mutant tumors of the nervous system.

A case of desmoplastic myxoid tumor, SMARCB1 mutant, in the pineal region.

Desmoplastic myxoid tumor (DMT), SMARCB1 mutant is a recently proposed new entity that mainly occurs in the pineal region and has epigenetic features similar to those of atypical teratoid/rhabdoid tumors (AT/RT)-MYC and poorly differentiated chordomas. Herein, we present a new case of a 33-year-old man with headaches, dizziness, nausea, vomiting, and blurred vision, who was initially found to have a suspicious germinoma on imaging. After surgical removal of the lesion, the postoperative pathological diagnosis was DMT, SMARCB1 mutant. To the best of our knowledge, this is the first case reported in China. Our findings also extend the range of the immunohistochemical phenotype of this rare tumor.

Primary myxoid temporal bone tumor: A rare neurosurgical manifestation of Carney complex?

BACKGROUND: Carney complex (CNC) is a rare autosomal dominant syndrome, manifesting mainly with cardiac, cutaneous, and mucosal myxomas. Osteochondromyxoma is known as an extremely rare bone lesion of CNC which usually appears early in life; however, there were no reports of primary bone myxoma of the skull in the patients with CNC. We present the first case of primary myxoid skull tumor in the patient with CNC. CASE DESCRIPTION: We report the left temporal bone tumor with significant intracranial mass effect in a 58-year- old woman already diagnosed with CNC. Complete resection of the tumor with skull bone reconstruction was carried out. Pathological diagnosis was labeled the lesion as an atypical myxoid spindle cell neoplasm. The features were different from atrial myxoma and osteochondromyxoma which has been described in CNC. There have been no signs of recurrence in 9 years follow-up. CONCLUSION: To the best of our knowledge, there have been no reports of the primary myxoid tumors in the skull in the patients with CNC. This paper highlighted a possible important association between CNC and primary intracranial myxoid tumors.

Intracranial myxoid mesenchymal tumor with EWSR1-CREB1 gene fusion: a case report and literature review.

Intracranial myxoid mesenchymal tumors harboring EWSR1 fusions with CREB transcriptional factor gene families were recently described in several case reports and a few case series and this tumor closely resembles the myxoid variant of angiomatoid fibrous histiocytoma. We herein present an intracranial mesenchymal myxoid tumor arising in the third ventricle of a middle-aged woman. The tumor displayed prominent myxoid features consisting of mildly atypical oval to round cells, arranged in reticular and cord-like structures, with starburst-like amianthoid fibers, whereas it lacked pseudoangiomatoid spaces, pseudocapsules and lymphoid cuffing. Immunophenotypically, tumor cells were positive for EMA, desmin, and ALK (focal). EWSR1 and CREB1 rearrangements were identified using FISH assay. The proliferation index was low. It is currently uncertain whether these myxoid tumors represent a variant of angiomatoid fibrous histiocytoma or a novel tumor entity.

Sleeve-Shaped Neurothekeoma of the Ulnar Nerve: A Unique Case of a Still Unclear Pathological Entity.

Background: Neurothekeomas are slow-growing, well-circumscribed benign neoplasms. They usually involve cutaneous or subcutaneous tissues. Although originally described as myxomas deriving from nerve sheath cells, their exact histological classification is still uncertain. Peripheral nerve localization is rarely reported. Here, we describe a unique case of sleeve-shaped neurothekeoma of the ulnar nerve, which was incidentally discovered during a cubital tunnel release surgery. Methods: A 57-year-old man was admitted at our institution with clinical, ultrasonographic, and electromyographic findings highly suggestive of cubital tunnel syndrome. During ulnar nerve decompression surgery, however, no bony or ligament compression was noticed, but a segment of the nerve wrapped by a thick sleeve-shaped tissue, which had no clear-cut cleavage plane from the nerve. Given this unexpected finding, the en bloc excision of the lesion was avoided. A nerve decompression with biopsy of the swelling portion of the lesion was performed instead. Results: Histological examination described abundant myxoid stroma, with epithelioid and ring-shaped cells arranged in cords, negative to S100 protein at immunohistochemical analysis. This pattern was suggestive of neurothekeoma. The patient showed improvement in hypermyotrophy and intrinsic weakness of the hand. Conclusions: To the best of our knowledge, this is the first report of a sleeve-shaped neurothekeoma of the ulnar nerve. The exact pathological characterization of such rare entities remains uncertain. In case of peripheral nerve localization, and when a clear cleavage plane is absent, the correct management of these lesions should be that of simple nerve decompression followed by biopsy.

Intracranial Myxoid Mesenchymal Tumor with Rare EWSR1-CREM Translocation.

Translocations between EWSR1 and members of the CREB family of transcription factors (CREB1, ATF1, and CREM) are rare genetic findings occurring in various sarcomas. Of these, the EWSR1-CREM translocation is the most rarely reported. We present the case of a 9-year-old boy who presented with a year of fatigue, weight loss, and abulia. A brain MRI revealed a frontal interhemispheric tumor arising from the falx. After resection, pathology demonstrated a myxoid mesenchymal tumor with an EWSR1-CREM translocation. A series of recent reports of similar tumors has generated ongoing debate in the literature over the classification of these tumors either as intracranial angiomatoid fibrous histiocytomas, which also harbor EWSR1-CREB family translocations, or as a novel diagnostic entity. The present case provides another example of the rare EWSR1-CREM fusion in an intracranial myxoid mesenchymal tumor that recurred in just 6 months despite gross total resection. The findings are discussed in the context of the existing literature and the ongoing effort to appropriately classify this type of tumor.

Comparison of the diagnostic performances of core needle biopsy in myxoid versus non-myxoid tumors.

BACKGROUND: Despite the overall diagnostic utility of core needle biopsy (CNB) comparable to incisional biopsy, increased diagnostic errors have been suggested of CNB for myxoid soft tissue tumors. This study compared the diagnostic performance of CNB between myxoid and non-myxoid soft tissue tumors. METHODS: 369 patients who underwent ultrasound-guided CNB prior to resection for soft tissue tumors were classified into two groups according to resection pathology; myxoid group (n = 75) and non-myxoid group (n = 294). One-hundred and ninety-three patients were male and the median age of the patients was 40 years. Two-hundred and sixty-three tumors were malignant. RESULTS: CNB correctly diagnosed malignancy in 84% (58 of 69) for the myxoid group and 95% (184 of 194) for the non-myxoid group. For diagnosing histologic grade of soft tissue sarcoma, CNB correctly identified high grade in 78% (18 of 23) for the myxoid group and 74% (94 of 128) for the non-myxoid group. Correct diagnosis rate of histological type was significantly lower in the myxoid group (63% [47 of 75] in the myxoid group and 83% [242 of 294] in the non-myxoid group, p = 0.013). CONCLUSION: Our study suggests that CNB is useful for myxoid soft tissue tumors of the extremity, with regard to diagnosing malignancy and histologic grade. However, CNB was less useful for identifying histologic subtype in myxoid tumors than in non-myxoid tumors.

Angiomiofibroblastoma-like, un tumor excepcional: presentación de un caso clínico y diagnóstico diferencial / Angiomyofibroblastoma-like, an exceptional tumor: presentation of a clinical case and differential diagnosis

Presentamos un caso de Angiomiofibroblastoma-like (AML), en el que la ecografía fue importante para determinar la detección, localización y extensión local. Hallazgos: La ecografía demostró una lesión paratesticular sólida hipoecogénica de bordes bien definidos lo que sugirió lesión benigna extratesticular. La histología evidenció una neoplasia mesenquimal benigna tipo mixoide en cuyo diagnóstico diferencial se incluyen el Angiomixoma superficial (AMS), Angiomixoma agresivo (AMA), Angiomiofibroblastoma (AMF) y el AML. En base a estos hallazgos se realizó una revisión de tumores de similares características en la literatura, llegando finalmente al diagnóstico de AML cuya localización paratesticular sólo ha sido descrita en muy pocos casos hasta la fecha. Conclusión: La ecografía es útil para localizar los tumores paratesticulares y determinar su extensión local. No obstante, para llegar al diagnóstico definitivo es necesario realizar un estudio histológico e inmunohistoquímico de la tumoración.

We present a case of a paratesticular Angiomiofibroblastoma-like (AML) tumor in which ultrasound was important to give the specific location and local extension of the lesion. Findings: Ultrasound revealed a hypoechoic paratesticular lesion with well-defined borders, suggesting an extratesticular benign lesion. The histology showed a benign mesenchymal myxoid-type neoplasm. The differential diagnosis included superficial Angiomyxoma (AMS), Aggressive angiomyxoma (AMA), Angiomyofibroblastoma (AMF) and AML. Based on these findings, a review of similar tumors was carried out and ultimately led to the diagnosis of paratesticular AML. This location has been described only in a few cases in the literature. Conclusion: Ultrasound is useful to locate paratesticular tumors and determine their local extension. However, a definitive diagnosis still requires a histological and immunohistochemical study.

Fine needle aspiration cytology findings of myxoinflammatory fibroblastic sarcoma: A case report.

Myxoinflammatory fibroblastic sarcoma (MIFS) is rare low-grade soft-tissue tumor that occurs in extremities. Clinically it is difficult to differentiate from benign lesions, such as nodular fasciitis, and malignant tumors, such as liposarcoma. We report a case of MIFS in the forearm of a 34-year-old man. The resected tumor measured 5.3 × 2.7 × 2.5 cm3 , had a lobular structure with indistinct boundary, and consisted of a large amount of translucent and yellow mucous-like substrate. Cytological examination of a preoperative puncture aspiration specimen showed histiocyte- and fibroblast-like tumor cells in a mucous-like matrix together with scattered lipoblast- and ganglion-like cells. Nuclear chromatin of the tumor cells showed a fine granular appearance but no notable hyperchromasia. There were no clear malignant findings. On Giemsa staining of the tumor cells, there were fine granular and hyaline intracytoplasmic substances that showed purple to reddish-purple metachromaticity. Prominent inflammatory cells were not observed in the specimens. MIFS should be considered in the differential diagnosis for a myxoid tumor in the extremities.

Cyto-Histo Correlation of a Very Rare Tumor: Superficial Angiomyxoma.

Superficial angiomyxoma (SA) is one of the superficially located myxoid soft tissue tumor. Because of the rarity of this tumor, there is paucity of fine needle aspiration cytology (FNAC) findings. Here, we present a case of SA in a 14-year-old girl who presented with a left leg swelling. The cytology of the lesion along with the histopathologic correlation is presented.

Superficial Acral Fibromyxoma: A Rare Soft Tissue Tumor.

Superficial acral fibromyxoma is a rare clinical entity, first described in 2001. It is a soft tissue tumor with a predilection for the fingers and toes. Since it was described, few cases have been reported. We present a case of an 88-year-old male with a history of a slow-growing lump in his left great toe after local trauma. The patient underwent surgical excision, and pathologic analysis revealed the diagnosis of superficial acral fibromyxoma. Although an unusual diagnosis, surgeons should be aware of this myxoid tumor, which requires complete surgical excision and short-term follow-up to detect recurrence.

Extraskeletal Myxoid Chondrosarcoma of Larynx / 대한이비인후과학회지

Primary cartilaginous tumors of the laryngeal lesion are rare and it accounts for only 1% of laryngeal tumor pathology. They are most commonly located on the endolaryngeal surface of cricoid cartilage, and it is extremely rare to find them in vocal muscle lesion. In most cases, treatment of choice is based on surgical excision, and postoperative radiotherapy is typically recommended. We experienced a case of a 22-year-old young woman without underlying disease, presenting extraskeletal myxoid chondrosarcoma of vocal cord, especially in the vocal muscle. The patient underwent mass excision through suspension laryngoscope and radiation therapy.

Useful MRI Features for Distinguishing Benign Peripheral Nerve Sheath Tumors and Myxoid Tumors in the Musculoskeletal System

PURPOSE: To identify the differential MRI findings between myxoid tumors and benign peripheral nerve sheath tumors (BPNSTs) in the musculoskeletal system. MATERIALS AND METHODS: The study participants included a total of 35 consecutive patients who underwent MRI between September 2011 and December 2013. The patients were pathologically diagnosed with myxoid tumors (22 patients) or BPNSTs (13 patients). Evaluation was done by two radiologists, based on the following characteristics: size, margin, degree of signal intensity (SI) on T2-weighted images (T2WI), homogeneity of SI on T2WI, enhancement pattern, enhancement homogeneity, presence of cystic portion, internal fat component, presence of fat split sign, presence of target sign, presence of continuation with adjacent neurovascular bundle, and presence of surrounding halo. RESULTS: Large size, high SI on T2WI, heterogeneous enhancement, and internal fat component were commonly observed in myxoid tumors, while homogenous enhancement, fat split sign, target sign were common in BPNSTs. The differences were statistically significant (P 0.05). CONCLUSION: In the differential diagnosis of myxoid tumors and BPNSTs involving the musculoskeletal system, several MRI findings such as degree of SI on T2WI, enhancement homogeneity, internal fat component, fat split sign, and target sign, may be helpful in establishing the diagnosis.