Multifocal Cytokeratin Expression in a Dedifferentiated Solitary Fibrous Tumor With Heterologous Rhabdomyosarcomatous Differentiation: A Challenging Diagnosis!

We report the case of a dedifferentiated solitary fibrous tumor with heterologous rhabdomyosarcomatous differentiation in a 74-year-old male presenting with a rapidly growing, large soft tissue tumoral mass in the gluteal muscles of the right hip. Dedifferentiation in solitary fibrous tumor had not been recognized until very recently and is an extremely rare phenomenon in this tumor type. In the present case, the diagnosis of dedifferentiated solitary fibrous tumor was difficult because of the absence of areas of conventional solitary fibrous tumor with a predominantly poorly differentiated, anaplastic tumor component in the incision biopsy composed of heterogeneous areas with small blue round cell (Ewing sarcoma-like), rhabdoid, epithelioid, and pleomorphic morphology. Moreover, the “unforeseen” strong patchy to multifocal positivity for cytokeratin AE1/AE3 and desmin made the diagnosis of a dedifferentiated solitary fibrous tumor even more challenging in this case. The morphology (presence of branching thin-walled, hemangiopericytoma-like blood vessels) and the immunohistochemical profile (including STAT6 and GRIA2 positivity) were very useful to differentiate this very challenging case of a cytokeratin-positive dedifferentiated solitary fibrous tumor with heterologous rhabdomyosarcomatous differentiation from a broad list of differential diagnoses.

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Malignant Solitary Fibrous Tumor of the Right Cerebellum: A Case Report

Case Reports in Neurology ◽

10.1159/000510844 ◽

2021 ◽

Vol 13 (1) ◽

pp. 259-266

Author(s):

Ye-Tao Zhu ◽

Yang Liu ◽

Li-Gang Chen ◽

Da-Ping Song

Keyword(s):

Central Nervous System ◽

Nervous System ◽

Solitary Fibrous Tumor ◽

Immunohistochemical Staining ◽

Biological Behavior ◽

Resonance Imaging ◽

Solitary Fibrous Tumors ◽

The Central Nervous System ◽

Fibrous Tumor ◽

The Right

Solitary fibrous tumor is a very rare mesenchymal tumor that occurs mostly in the pleura, and there are few reported cases of a presence in the central nervous system, particularly in the cerebellum. In 2016, the WHO classified solitary fibrous tumors into grade I. In this article, we present a case of malignant solitary fibrous tumor recurring 8 years after surgery in a 63-year-old male. Magnetic resonance imaging showed low to intermediate mixed signal intensity on T1W1. Immunohistochemical staining positivity for Vimentin, CD99, CD34 and Bcl-2, it is consistent with the immunohistochemical characteristics of solitary fibrous tumor. We resected the patient’s tumor, and the patient was followed up for 3 months with no signs of recurrence. Solitary fibrous tumors are very rare in the central nervous system. Immunohistochemical staining positivity for CD34 and Bcl-2 is strongly expressed in most solitary fibrous tumor. Surgical resection is the preferred treatment. Due to the small number of cases, the biological behavior and prognosis of this tumor need to be further explored.

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BCOR-CCNB3-positive soft tissue sarcoma with round-cell and spindle-cell histology: a series of four cases highlighting the pitfall of mimicking poorly differentiated synovial sarcoma

Histopathology ◽

10.1111/his.13001 ◽

2016 ◽

Vol 69 (5) ◽

pp. 792-801 ◽

Cited By ~ 25

Author(s):

Wan-Shan Li ◽

I-Chuang Liao ◽

Mei-Chin Wen ◽

Howard Haw-Chang Lan ◽

Shih-Chen Yu ◽

...

Keyword(s):

Soft Tissue ◽

Soft Tissue Sarcoma ◽

Synovial Sarcoma ◽

Spindle Cell ◽

Round Cell ◽

Poorly Differentiated

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Myxoid and Lipomatous Solitary Fibrous Tumor of Soft Tissue: A Case Description

Open Journal of Pathology ◽

10.4236/ojpathology.2017.71003 ◽

2017 ◽

Vol 07 (01) ◽

pp. 20-24

Author(s):

Javier Ortiz Rodríguez-Parets ◽

Cristina González Velasco ◽

Elisa Muñoz Torres ◽

María Dolores Ludeña de la Cruz

Keyword(s):

Soft Tissue ◽

Solitary Fibrous Tumor ◽

Case Description ◽

Fibrous Tumor

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Solitary fibrous tumor of the pleura mimicking a soft tissue sarcoma of the chest wall

International Journal of Surgery Case Reports ◽

10.1016/j.ijscr.2021.106746 ◽

2021 ◽

pp. 106746

Author(s):

Kentaro Watanabe ◽

Yuya Takabe ◽

Shuhei Iizuka ◽

Yoshiro Otsuki ◽

Toru Nakamura

Keyword(s):

Soft Tissue ◽

Soft Tissue Sarcoma ◽

Chest Wall ◽

Solitary Fibrous Tumor ◽

Fibrous Tumor

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Spontaneous Regression of a Mandibular Plasmacytoma in a Juvenile Dog: A Case Report

Journal of the American Animal Hospital Association ◽

10.5326/jaaha-ms-6932 ◽

2020 ◽

Vol 56 (3) ◽

Author(s):

Erika Villedieu ◽

Samuel Beck ◽

Laurent Findji

Keyword(s):

Computed Tomography ◽

Spontaneous Regression ◽

Round Cell ◽

Computed Tomography Scan ◽

Computed Tomography Scanning ◽

Cell Neoplasm ◽

Poorly Differentiated ◽

The Right ◽

Tomography Scan ◽

Tomography Scanning

ABSTRACT A 4 mo old female Finnish lapphund presented for further investigation of a swelling of the right rostral mandible. A computed tomography scan showed the swelling to be an expansile and osteolytic mandibular lesion. Histopathology revealed a poorly differentiated, moderately well-demarcated, unencapsulated, highly infiltrative round cell neoplasm, and immunohistochemistry was supportive of a plasmacytoma. Performance of a rostral partial mandibulectomy was initially discussed with the owners, but the lesion improved spontaneously both clinically and on repeated computed tomography scanning before surgery could be performed. It subsequently almost completely resolved 6 mo after diagnosis. Hypotheses for spontaneous regression of the lesion are discussed and the human literature is briefly reviewed.

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Extrapleural Benign Solitary Fibrous Tumor in the Shoulder of a 9-Year-Old Girl: Case Report and Review of the Literature

Pediatric and Developmental Pathology ◽

10.1007/s10024-004-6065-7 ◽

2004 ◽

Vol 7 (6) ◽

pp. 653-660 ◽

Cited By ~ 15

Author(s):

Dinesh Rakheja ◽

Kathleen S. Wilson ◽

John J. Meehan ◽

Roger A. Schultz ◽

Gerhard E. Maale ◽

...

Keyword(s):

Case Report ◽

Solitary Fibrous Tumor ◽

Cytogenetic Analysis ◽

Young Age ◽

Review Of The Literature ◽

Unusual Location ◽

Fibrous Tumor ◽

The Right

We report a case of a benign solitary fibrous tumor that occurred in the right shoulder of a 9-year-old girl. This case is remarkable due to the unusual location of its occurrence and the young age of the patient. In addition, cytogenetic analysis revealed a karyotype unreported in this neoplasm: 46,XX,der(4)t(4;9)(q31.1;q34), del(9)(p22p24),der(9)t(4;9)(q31.1;q34)ins(9;?)(q34;?) (17 cells)/46,XX (3 cells).

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A pelvic cavity malignant solitary fibrous tumor with dedifferentiation and multifocal cytokeratin expression

10.21203/rs.3.rs-60966/v1 ◽

2020 ◽

Author(s):

Yan He ◽

Guan Huang ◽

Wensong Lin ◽

Zhaohui Zheng ◽

Haiyan Zhao

Keyword(s):

Laparoscopic Surgery ◽

Solitary Fibrous Tumor ◽

Malignant Tumors ◽

Benign Lesion ◽

Pelvic Mass ◽

Clinical Image ◽

Pelvic Cavity ◽

Cytokeratin Expression ◽

Mesenchymal Neoplasm ◽

Fibrous Tumor

Abstract Background: Solitary fibrous tumor is an uncommon mesenchymal neoplasm that originates from fibroblasts and occurs predominantly in the visceral pleura. Pelvic cavity small sized malignant solitary fibrous tumor is very rare; it is easily misjudged by surgeons as a benign lesion and resected by laparoscopic surgery. When accompanied by dedifferentiation, malignant solitary fibrous tumor is difficult to diagnose by pathologists. Here, we describe a challenging case.Case presentation: A 47-year-old man was accidentally found to have a pelvic mass for three months, with pain and distension for seven days. The mass was adhered and compressed to the ureter and bladder. The right side of the pelvic cavity had a palpable and substantial mass, with no obvious associated pain. With an assumed diagnosis of a benign tumor, the patient underwent laparoscopic surgery to resect the tumor. Histologically, spindle cell areas and dedifferentiated areas were observed. Immunohistochemical analysis of dedifferentiated regions revealed cytokeratin showed multifocal expression. Vimentin and CD34 were abnormal negative. This case was diagnosed as a MSFT with dedifferentiation. The patient was well after the operation, but, unfortunately, he had a recurrence one year later.Conclusion: Pelvic cavity malignant solitary fibrous tumor is a rare tumor that is in frequently dedifferentiated and exhibiting cytokeratin expression. The diagnosis of this type of tumor can be confusing, and it should be distinguished from Synovial Sarcoma, Liposarcoma, and other malignant tumors. The expression of cytokeratin and the absence of vimentin and CD34 are pitfalls to diagnosis. In this case, there was still a high degree of malignancy despite the small size of the tumor. Clinical-image-pathological multidisciplinary analysis has a great effect on diagnosis and therapy of diseases. This case is a cautionary tale for surgeons and pathologists.

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Solitary Fibrous Tumor, Soft Tissue

Encyclopedia of Pathology ◽

10.1007/978-3-319-28845-1_5490-1 ◽

2019 ◽

pp. 1-10

Author(s):

Elizabeth G. Demicco

Keyword(s):

Soft Tissue ◽

Solitary Fibrous Tumor ◽

Fibrous Tumor

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Solitary Fibrous Tumor of the Spinal Cord: Case Report and Review of the Literature

Neurosurgery ◽

10.1227/01.neu.0000130037.45768.84 ◽

2004 ◽

Vol 55 (2) ◽

pp. E433-E438 ◽

Cited By ~ 21

Author(s):

Mitsuhiro Kawamura ◽

Kazutaka Izawa ◽

Noboru Hosono ◽

Hiroshi Hirano

Keyword(s):

Spinal Cord ◽

Solitary Fibrous Tumor ◽

Spinal Cord Tumor ◽

Clinical Manifestations ◽

Thoracic Spinal Cord ◽

Thoracic Spinal ◽

Spindle Cell Proliferation ◽

Long Term Follow Up ◽

Fibrous Tumor ◽

The Right

Abstract OBJECTIVE AND IMPORTANCE: A solitary fibrous tumor (SFT) is a rare neoplasm of probable mesenchymal origin that was first reported in the pleura but can occur in different sites. Only six cases of SFT arising from the spinal cord have been reported. CLINICAL PRESENTATION: We report a case of primary SFT occurring in the thoracic spinal cord in a 64-year-old man with Brown-Séquard syndrome. Magnetic resonance imaging revealed an intradural mass at the level of T2–T3. INTERVENTION: Total T2–T3 laminectomies were performed. The tumor appeared to be adherent to the right lateral aspect of the cord but not attached to the meninges. On histological examination, the tumor exhibited spindle cell proliferation with abundant dense collagen but without a hemangiopericytomatous pattern. Immunohistochemically, the tumor cells were reactive with CD34 and vimentin only. CONCLUSION: We report a rare case of SFT occurring in the thoracic spinal cord. Histologically and immunohistochemically, we confirmed the diagnosis of SFT. Low signal intensity on T1- and T2-weighted images corresponded to the histological findings. When a spinal cord tumor exhibits a signal pattern similar to this, SFT should be included in the differential diagnosis. Because of the rarity of reports on this condition, the clinical manifestations and course of SFT of the spinal cord are unknown, and careful long-term follow-up is recommended.

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