Primary intrathoracic low-grade fibromyxoid sarcoma

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

BACKGROUND

Multiple 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 PRESENTATION

A 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.

CONCLUSION

We 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.

Case report: Primary pleural low-grade fibromyxoid sarcoma in a 4-year-old boy with molecular confirmation

Low-grade fibromyxoid sarcoma (LGFMS) is a rare malignant fibroblastic tumor, principally affecting the deep tissues of the proximal trunk and extremities in young adults. However, primary pleural LGFMS is extremely rare, and only three cases have been reported in the previous English literature without genetic confirmation. Furthermore, the historical pleural LGFMS cases were all adults, and the primary pleural LGFMS in children has never been reported to date. Here, we presented a primary pleural LGFMS in a 4-year-old boy with detailed clinical, pathological, and molecular results. Histologically, the current tumor showed typical alternating collagenous and myxoid areas, containing spindled or oval tumor cells arranged in a whorled and short fascicular pattern. In some areas, the tumor cells exhibited moderate atypia, and mitotic figures were identified but without the identification of giant collagen rosettes. Immunohistochemically, all the neoplastic cells showed strong and diffuse positivity for MUC4. Genetically, FUS gene rearrangement was revealed by fluorescence in-situ hybridization (FISH), and subsequently, next-generation sequencing (NGS) and polymerase chain reaction (PCR) further demonstrated the FUS::CREB3L2 fusion transcript. To the best of our knowledge, this is the first case of primary pleural LGFMS with the identification of FUS gene rearrangement and FUS::CREB3L2 fusion in a 4-year-old child. Our study expands the age range of pleural LGFMS and highlights the combination of morphological, immunohistochemical, and molecular analyses in such challenging cases.

Rapidly developing intrathoracic low-grade fibromyxoid sarcoma: A case report

Low-grade fibromyxoid sarcoma (LGFMS) is a rare mesenchymal tumor that primarily arises in the limbs and trunk of young adults, and rarely in the thoracic cavity. An 84-year-old Japanese woman presented with a right intrathoracic mass which was 8 cm in size. CT-guided needle biopsy did not provide a definitive diagnosis. Perioperatively, a mass was found in the right lower lobe of the lung and was suspected to have invaded the chest wall at the sixth-eighth ribs. A right lower lobectomy and combined chest wall resection were performed. Microscopic examination revealed that the tumor was a low-grade spindle cell tumor originating from the pleura demonstrating focal invasion of the lung. The tumor exhibited positivity for MUC4, and FUS gene translocation was confirmed through fluorescence in situ hybridization. Unfortunately, 10 months postoperatively, tumor recurrence was noted as peritoneal dissemination, and the patient passed away 13 months postoperatively. Although LGFMS may be diagnosed histologically as a low-grade tumor by needle biopsy, in this case, it was highly malignant. Postoperative long-term regular medical follow-up is recommended considering the highly malignant nature of the tumor and the high risk of local recurrence and pulmonary metastasis.

Superficial low-grade fibromyxoid sarcoma

BACKGROUND

Low-grade fibromyxoid sarcoma (LGFMS) typically involves deep soft tissue (beneath the fascia) of the proximal extremities and trunk. Long-term follow-up has shown a high rate of local recurrence, metastasis, and death. To the best of our knowledge, there is only one previous large series focusing on superficial LGFMS suggesting superficial tumors are disproportionately more common in children and may have a better prognosis. Our study's primary goals are to confirm these findings and increase general awareness that LGFMS may arise in superficial soft tissue.

METHODS

We retrieved our cases of superficial LGFMS diagnosed between 2008 and 2020. Available slides were reviewed, and clinical data and follow-up information were obtained.

RESULTS

The patients included nine males and 14 females with a median age of 29 years; eight (35%) were children (<18 years) and five (22%) were young adults (18-30 years). The majority involved the lower extremities (65%). The tumors were primarily centered in the subcutis (91%) and dermis (9%). Microscopically, they had typical features of LGFMS with alternating fibrous and myxoid zones composed of bland, slightly hyperchromatic spindled cells. All were positive for MUC4 by immunohistochemistry and/or FUS rearrangement by FISH. Follow-up on 14 cases ranged from 11 to 148 months (median 61 months) with no evidence of recurrences or distant metastases.

CONCLUSIONS

Compared to conventional deep-seated counterparts, superficial LGFMS is more likely to occur in the extremities of children and young adults and may have a better clinical outcome. Further studies with longer follow-up will likely help support these findings.

Case report and review of literature: Resection of a huge mediastinal low-grade fibromyxoid sarcoma with neck, axillary, and lung involvement

Low-grade fibromyxoid sarcoma is an extremely rare malignant neoplasm, with an incidence of 0.18 per million, and comprises 0.6% of all soft tissue sarcomas. It has a high recurrence rate and late metastatic spread and is chemotherapy and radiotherapy insensitive. This paper reports a case of an unusually large mediastinal low-grade fibromyxoid sarcoma in a 55-year-old patient. The tumor was engulfing the main blood vessels of the mediastinum, involving the lung, and extending beyond the chest cavity to involve the cervical and axillary regions. The patient has a 21-year history of frequent surgical resections for lesions that were repeatedly misdiagnosed as neurofibroma. The tumor was successfully resected by a challenging operation that involved mediastinal mass resection, chest wall mass resection, and wedge resection of the left upper lobe of the lung. The deceivingly benign-looking histology of this tumor makes it a commonly misdiagnosed one, requiring careful assessment by pathologists to reach the right diagnosis. Surgical resection with clear margins remains the treatment of choice for these lesions. Due to the behavior of this tumor, once detected and managed, extensive long-term follow-up is always recommended.

Update of pediatric soft tissue tumors with review of conventional MRI appearance-part 1: tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors

There are numerous soft tissue tumors and tumor-like conditions in the pediatric population. Magnetic resonance imaging is the most useful modality for imaging these lesions. Although certain soft tissue lesions exhibit magnetic resonance features characteristic of a specific diagnosis, most lesions are indeterminate, and a biopsy is necessary for diagnosis. We provide a detailed update of soft tissue tumors and tumor-like conditions that occur in the pediatric population, emphasizing each lesion's conventional magnetic resonance imaging appearance, using the recently released 5th edition of the World Health Organization Classification of Soft Tissue and Bone Tumors as a guide. In part one of this review, pediatric tumor-like lesions, adipocytic tumors, fibroblastic and myofibroblastic tumors, and perivascular tumors are discussed. In part two, vascular lesions, fibrohistiocytic tumors, muscle tumors, peripheral nerve sheath tumors, tumors of uncertain differentiation, and undifferentiated small round cell sarcomas are reviewed. Per the convention of the WHO, these lesions involve the connective, subcutaneous, and other non-parenchymatous-organ soft tissues, as well as the peripheral and autonomic nervous system.

Case Report: Primary Thoracic Low-Grade Fibromyxoid Sarcoma in a Young Girl Presenting With Mediastinal Mass Syndrome

Low-grade fibromyxoid sarcomas (LGFMSs) are typically adult-onset tumors that arise from the extremities. Here, we report an exceptional case of primary thoracic LGFMS in an 8-year-old girl that resulted in mediastinal syndrome. In reporting this case, we discuss the clinical challenges, role of molecular profiling and review reported cases of pediatric thoracic LGFMSs.

Primary Soft Tissue Sarcoma of the Heart: An Emerging Chapter in Cardio-Oncology

Primary malignant cardiac tumors are rare, with a prevalence of about 0.01% among all cancer histotypes. At least 60% of them are primary soft tissue sarcomas of the heart (pSTS-h) that represent almost 1% of all STSs. The cardiac site of origin is the best way to classify pSTS-h as it is directly linked to the surgical approach for cancer removal. Indeed, histological differentiation should integrate the classification to provide insights into prognosis and survival expectancy of the patients. The prognosis of pSTS-h is severe and mostly influenced by the primary localization of the tumor, the difficulty in achieving complete surgical and pharmacological eradication, and the aggressive biological features of malignant cells. This review aims to provide a detailed literature overview of the most relevant issues on primary soft tissue sarcoma of the heart and highlight potential diagnostic and therapeutic future perspectives.

Low-grade fibromyxoid sarcoma incidentally discovered as an asymptomatic mediastinal mass: a case report and review of the literature

BACKGROUND

Low-grade fibromyxoid sarcoma (LGFMS) is a rare tumor characterized by bland histological features and aggressive clinical course. The most common anatomic locations of occurrence are the lower extremities, thorax, inguinal area, and upper limbs. Primary mediastinal sarcomas are even rarer. To the best of our knowledge, only seven cases of primary mediastinal LGFMS have been reported in the literature. Here, we report a case of primary mediastinal LGFMS.

CASE PRESENTATION

A 26-year-old Pakistani man presented with fever and vomiting for the past 2 months. On a routine chest x-ray, a mediastinal mass was incidentally found. Computed tomography (CT) scan showed a large circumscribed lobulated soft tissue density mass lesion in an anterior mediastinum. Grossly, the resected mass measured 17.0 × 12.0 × 11.0 cm. The cut surface was gray white with a whorled-like appearance and foci of calcification and cystic changes. Histologically, a spindle cell lesion was seen with alternating myxoid and hyalinized areas. The shaped cells were arranged in bundles. Immunohistochemical staining showed positive reactivity patterns with MUC4 and focally for epithelial membrane antigen (EMA). The diagnosis was confirmed as LGFMS. The patient is free of symptoms and recurrence 22 months after the surgery.

CONCLUSION

In conclusion, we report a rare case of primary mediastinal LGFMS in a young male patient that was discovered incidentally. Our patient is on regular follow-up to look for evidence of recurrence as these tumors are prone to recurrences.

Low-grade fibromyxoid sarcoma: A rare case in an unusual location

Low-grade fibromyxoid sarcoma, also known as Evans tumor, is a low-grade sarcoma that most commonly arises in the deep soft tissue of the proximal extremities or trunk in young adults. It is very rare in the viscera as a primary site, with only a few cases reported in the literature. Here, we present a case of Evans tumor occurring in an unusual and rarely reported location; an intrathoracic mass arising from the diaphragmatic pleura.

Low-grade fibromyxoid sarcoma: A report of the Cooperative Weichteilsarkom Studiengruppe (CWS)

BACKGROUND

Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft-tissue tumor with benign histologic appearance, though fully malignant behavior is possible.

METHODS

Patients with LGFMS <21 years registered in Cooperative Weichteilsarkom Studiengruppe trials until 2017 were analyzed. Firstline treatment consisted of complete surgical resection whenever possible.

RESULTS

Median age of 31 patients was 10.9 years (first month to 17.1 years). Twenty-six tumors were confirmed to the tissue of origin (T1), four invaded contiguous structures (T2), one was TX. Eight were >5 cm. The best surgical result was resection with free margins (R0) in 24 and microscopic residuals (R1) in seven. Five-year event-free (EFS), 5-year local-relapse-free (LRFS), and 5-year overall-survival were 71 ± 18.6% confidence interval (CI) 95%, 76 ± 17.6% CI 95%, and 100%, respectively. Six patients suffered local relapse in a median of 1 year, one combined within 1.3 year and one metastatic relapse with lesions in the lung, back muscles, and thigh discovered in whole-body imaging 6 years after the first diagnosis. In univariate analysis, T status correlated with EFS (T1 79.6 ± 18.6%, T2 50.0 ± 49.0%, P = .038). Resection with free margins tends to be associated with better LRFS (R0 82.4 ± 18.6%, R1 53.6 ± 39.4%, P = .053). Among 24 patients with R0 resection, five (21%) suffered relapse, thereof three local, one metastatic, and one combined. Among seven patients with R1-resection, three (43%) suffered local relapse.

CONCLUSION

Special caution is advisable in T2 tumors. The metastatic potential with lesions in unusual sites indicates that affected patients need to be informed. If long-term follow-up with whole-body imaging is beneficial, it may be addressed in larger intergroup analyses. Further research in disease biology is essential for optimal treatment and follow-up care.

Primary Multicentric Pulmonary Low-grade Fibromyxoid Sarcoma and Chelonid Alphaherpesvirus 5 Detection in a Leatherback Sea Turtle (Dermochelys coriacea)

We describe the gross, microscopical, histochemical and immunohistochemical features of a sclerosing pneumopathic disease process resembling primary multicentric pulmonary low-grade fibromyxoid sarcoma in a juvenile female leatherback sea turtle (Dermochelys coriacea). The animal was fresh, presented in good body condition and stranded dead in Aracaju, Sergipe state, Brazil, in September, 2017. Grossly, the lungs were enlarged bilaterally and the parenchyma was replaced by large, coalescing, white, firm masses that extended into the bronchi and bronchioles and to the pleura. Microscopically, these masses consisted of paucicellular populations of well-differentiated, spindle-shaped fibroblasts with low pleomorphism and low mitotic count, but tissue invasion. Abundant collagen in compact areas merged with peripheral fibromyxoid foci and inflamed stroma. Antibodies specific for cytokeratins AE1/AE3 and smooth muscle actin (SMA) labelled pneumocytes lining the remaining distorted alveoli and the hypertrophied and hyperplastic bronchial muscles, respectively. Tumour cells were negative for SMA; neither neoplastic nor normal tissues cross-reacted with antibodies specific for vimentin or Ki67. Chelonid alphaherpesvirus 5 (ChHV5) polymerase chain reaction analysis from formalin-fixed, paraffin wax-embedded lung tissue sections amplified a 450 base pair fragment of DNA-polymerase (UL30 region) that had 100% homology to sequences previously detected in green sea turtles (Chelonia mydas) on the Brazilian coast. Enterocolitis was a concomitant condition that likely caused morbidity in this case. These findings contribute to the body of knowledge on sea turtle health and expand the known geographical range for ChHV5 in the southern hemisphere.

Mesenchymal tumours of the mediastinum--part I

The mediastinum is an anatomically defined space in which organs and major blood vessels reside with surrounding soft tissue elements. The thymus is an important organ in the mediastinum, and many of the masses encountered in the mediastinum are related to this organ. Most neoplasms diagnosed in the mediastinum are epithelial tumours (thymomas and thymic carcinomas), lymphomas or germ cell tumours. In contrast, soft tissue tumours of the mediastinum are rare. In 1963, Pachter and Lattes systematically reviewed soft tissue pathology of the mediastinum, covering the hitherto described [2, 226, 227] In this review, based on the 2013 WHO classification of soft tissue tumours and the 2015 WHO classification of tumours of the lung, pleura, thymus and heart, we provide an updated overview of mesenchymal tumours that may be encountered in the mediastinum.

Low-Grade Fibromyxoid Sarcoma of the Head and Neck: A Clinicopathologic Series and Review of the Literature

Low-grade fibromyxoid sarcoma (LGFMS) is a deceptively bland malignancy with potential for late recurrence and metastasis, which usually occurs in the deep soft tissues of the extremities and trunk. Most LGFMSs harbor a characteristic gene fusion of FUS-CREB3L2, and recently MUC4 immunostaining has been found to be highly sensitive and specific for the diagnosis. We present a dedicated series of head and neck LGFMS, including the first reported laryngeal case, as well as a review of reported head and neck cases. The surgical pathology archives of our three institutions were searched for cases of LGFMS arising within the head and neck, and four cases were identified. The H&E slides were reviewed, and immunohistochemistry were performed for pancytokeratin, p63, p40, EMA, S100 protein, β-catenin, actin, CD34, and MUC4. The patients were 6, 43, 45, and 73 years old (mean 41.8 years) and included three males and one female. The tumors were located in the posterior cervical spine, facial skin, mandible, and larynx. The tumors were treated with surgical excision, and all four had histologic features typical for LGFMS including alternating myxoid and fibrous areas with prominent curvilinear vasculature. All tumors were MUC4 positive (100%), 2/4 (50%) were p63 positive, 1/4 (25%) showed focal EMA positivity; all 4 were negative for pancytokeratin, p40, S100 protein, β-catenin, actin, and CD34. LGFMS is a low grade sarcoma that rarely develops in the head and neck. Due to its rarity, a pathologist may not consider LGFMS in the differential diagnosis of spindle cell neoplasms within the head and neck. Immunohistochemical staining is helpful, but stains should be selected carefully to avoid misdiagnosis.

The clinical significance of the FUS-CREB3L2 translocation in low-grade fibromyxoid sarcoma

Background

Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft-tissue neoplasm with a deceptively benign histological appearance. Local recurrences and metastases can manifest many years following excision. The FUS-CREB3L2 gene translocation, which occurs commonly in LGFMS, may be detected by reverse-transcriptase polymerase chain reaction (RT-PCR) and fluorescence in situ hybridisation (FISH). We assessed the relationship between clinical outcome and translocation test result by both methods.

Methods

We report genetic analysis of 23 LGFMS cases and clinical outcomes of 18 patients with mean age of 40.6 years. During follow-up (mean 24.8 months), there were no cases of local recurrence or metastasis. One case was referred with a third recurrence of a para-spinal tumour previously incorrectly diagnosed as a neurofibroma.

Results

Results showed 50% of cases tested positive for the FUS-CREB3L2 translocation by RT-PCR and 81.8% by FISH, suggesting FISH is more sensitive than RT-PCR for confirming LGFMS diagnosis. Patients testing positive by both methods tended to be younger and had larger tumours. Despite this, there was no difference in clinical outcome seen during short and medium-term follow-up.

Conclusions

RT-PCR and FISH for the FUS-CREB3L2 fusion transcript are useful tools for confirming LGFMS diagnosis, but have no role in predicting medium-term clinical outcome. Due to the propensity for late recurrence or metastasis, wide excision is essential, and longer-term follow-up is required. This may identify a difference in long-term clinical outcome between translocation-positive and negative patients.

Successfully resected intrathoracic low-grade fibromyxoid sarcoma

A low-grade fibromyxoid sarcoma (LGFMS), an Evans tumor, is highly unusual. It is rarely described as a primary neoplasm in the thoracic cavity. We experienced a case of a 20-year-old woman with a right intrathoracic tumor that was surgically treated. Postoperative pathology of the resected specimen revealed the tumor to be LGFMS based on its histological appearance, immunohistological staining, and evidence of fused in sarcoma (FUS) translocation by fluorescence in situ hybridization. Tumor resection was performed with a free surgical margin, and the resultant chest wall defect was repaired using prosthetic mesh. The patient has been well without any recurrence for 18 months since surgery.

Fusion of the FUS and CREB3L2 genes in a supernumerary ring chromosome in low-grade fibromyxoid sarcoma

Low-grade fibromyxoid sarcoma (LGFMS) is a rare, low-grade malignant soft tissue tumor that is often mistaken for either benign or more malignant tumor types. Commonly, this tumor affects young adults and typically arises in the deep proximal extremities or trunk with frequent recurrences and can metastasize to the lungs many years later. Most cases have a recurrent balanced translocation involving chromosomes 7 and 16, t(7;16)(q32-34;p11), which leads to the fusion of the FUS and CREB3L2 genes. However, supernumerary ring chromosomes have been identified in a subset of FUS/CREB3L2-positive LGFMS, but it has not yet been formally demonstrated that such ring chromosomes harbor the FUS/CREB3L2 fusion gene. Here, we report the genetic findings of a supernumerary ring chromosome from an LGFMS from a 77-year-old man. Chromosome banding analysis revealed a supernumerary ring chromosome, and further studies with fluorescence in situ hybridization and reverse transcriptase-polymerase chain reaction (RT-PCR) showed that the ring contained material from chromosomes 7 and 16, that the FUS gene was present in two rearranged copies, and that it expressed the FUS/CREB3L2 fusion gene. Moreover, an assessment of previously reported cases showed that tumors with ring chromosomes relapsed more often than tumors with a balanced t(7;16), suggesting that ring formation in LGFMS is correlated with tumor progression.

Low-grade fibromyxoid sarcoma of the medial vastus: a case report

Low-grade fibromyxoid sarcoma (LGFMS) was first described by Evans in 1987, and since then, just over 150 cases have been reported, showing the rarity of this tumor. We report the clinical case of a 56-year-old man with a swelling on the distal third of the left thigh. The mass had grown in the course of 1 year and was surgically excised, obtaining complete resolution. Immuno-histological examination demonstrated the lesion to be a LGFMS, defined as a benign tumor but with a high incidence of local and distant recurrence (5-10%). At 2-year follow-up the patient was disease-free, confirming the efficacy of the surgical excision. In literature, the frequency of incomplete excision of LGFMS due to inappropriate diagnosis is stressed. It is this element that contributes most to the high rate of recurrence. We recommend that the eventuality of observing this rare tumor be borne in mind, and that care be taken to perform a complete, ample excision.

Massive low-grade fibromyxoid sarcoma presenting as acute respiratory distress in a 12-year-old girl

Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft-tissue sarcoma that usually presents in young adults as a painless, slow-growing mass. Evans first described LGFMS in 1987 as a spindle-cell sarcoma with bland histological features and paradoxically aggressive behavior. Although young adults are most frequently affected, recent reports describe pediatric cases being increasingly more common. Males and females are affected approximately equally and common locations include the deep soft tissue of the lower extremity, particularly the thigh and trunk. Primary occurrence within the chest cavity is exceedingly rare. Local recurrence and metastasis are not uncommon and present the clinician and radiologist with challenges regarding follow-up recommendations. Review of the literature reveals many cases of slowly progressive symptoms related to a mass effect. We present a healthy 12-year-old African-American girl who interestingly developed acute symptoms of shortness of breath and chest pain while playing with her brother.