Sclerosing rhabdomyosarcoma: report of a case arising in the head and neck of an adult and review of the literature

Multifaceted Spindle Cell/Sclerosing Rhabdomyosarcoma With Role of Immunohistochemistry in Avoiding Misdiagnosis: A Multi-Institutional Study of 45 Distinct Tumors

Background. Spindle cell/sclerosing rhabdomyosarcoma is a rare neoplasm and has an aggressive clinical course. Because of its rarity, we performed a multi-institutional collaboration to comprehend the overarching clinical, histopathological, and immunohistochemical characteristics of a cohort of spindle cell/sclerosing rhabdomyosarcoma. Materials and Methods. Forty-five patients with spindle cell/sclerosing rhabdomyosarcoma were identified. Demographics, clinical, histopathological, and immunohistochemistry data were reviewed and recorded. Results. The patients' age ranged from 1 to 85 years with a male to female ratio of 1.2:1. There were 15 children/adolescents and 30 adults. Eighteen (40%) tumors were located in the head and neck region. Twenty-four (53%) tumors displayed a bimorphic cellular arrangement with hypercellular areas having short, long, and sweeping fascicular and herringbone pattern, and hypocellular areas with stromal sclerosis and associated hyalinized and/or chondromyxoid matrix. Histomorphological differentials considered were leiomyosarcoma, malignant peripheral nerve sheath tumor, fibrosarcoma, nodular fasciitis, liposarcoma, synovial sarcoma, sarcomatoid carcinoma, solitary fibrous tumor, dermatofibrosarcoma protuberans, and schwannoma. Six tumors exhibited marked stromal sclerosis. The myogenic nature was confirmed by immunohistochemistry. Positivity for at least one skeletal muscle-associated marker (MyoD1 and/or myogenin) was observed. Conclusion. Spindle cell/sclerosing rhabdomyosarcoma diagnosis can be challenging as a number of malignant spindle cell neoplasm mimic this entity. Thus a correct diagnosis requires immunohistochemical work up with a broad panel of antibodies. In view of rarity of this neoplasm, further studies on a large cohort of patients with clinical follow-up data are needed for a better understanding of this tumor.

Cytomorphology of spindle cell/sclerosing rhabdomyosarcoma, including MYOD1 (LI22R) mutation result

Spindle cell/sclerosing rhabdomyosarcoma (RMS), characterized by MYOD1 (L122R) mutation in a subset of cases is a newly described subtype of RMS. Presently, there is no documentation of cytomorphological features, especially of sclerosing RMS. Case 1: A 24-year-old male presented with pain and swelling in his wrist for a one-year duration. MRI revealed a well-defined soft tissue lesion measuring 5.3 cm, encasing the lower end of the ulna. Fine-needle aspiration cytology (FNAC) smears revealed clusters of tumor cells with round to oval to spindle-shaped nuclei, scant to moderate amount of cytoplasm with the wisps of the metachromatic stroma. Histopathological examination revealed a malignant tumor comprising cells with polygonal to spindle-shaped nuclei, arranged in a sclerotic stroma. Immunohistochemically, the tumor cells were positive for desmin, myogenin, and MYOD1. A diagnosis of sclerosing RMS was offered. Furthermore, the tumor revealed MYOD1 (L122R) mutation. Case 2: A 43-year-old male presented with a 4-month history of "nasal stuffiness" and pressure. Imaging revealed a poorly defined infiltrative lesion in his nasal cavity. FNAC smears revealed loose and tightly cohesive clusters of malignant cells with oval to spindle-shaped nuclei, a moderate amount of ill-defined bluish to finely vacuolated cytoplasm, and focal streak artifact with interspersed stromal fragments. Histopathological examination revealed a malignant tumor composed of oval to spindle-shaped nuclei, embedded in a variably hyalinized stroma. Immunohistochemically, the tumor cells were positive for desmin, and myogenin. Diagnosis of spindle cell/sclerosing RMS was offered. The present study constitutes one of the first documentation of cytomorphological features of two rare cases of spindle cell/sclerosing RMS. The differential diagnoses and treatment-related implications are presented.

Molecular profile of head and neck rhabdomyosarcomas: A systematic review and meta-analysis

OBJECTIVE

This systematic review aimed to identify the molecular alterations of head and neck rhabdomyosarcomas (HNRMS) and their prognostic values.

STUDY DESIGN

An electronic search was performed using PubMed, Embase, Scopus, and Web of Science with a designed search strategy. Inclusion criteria comprised cases of primary HNRMS with an established histopathological diagnosis and molecular analysis. Forty-nine studies were included and were appraised for methodological quality using the Joanna Briggs Institute Critical Appraisal tools. Five studies were selected for meta-analysis.

RESULTS

HNRMS predominantly affects pediatric patients (44.4%), and the parameningeal region (57.7%) is the most common location. The alveolar variant (43.2%) predominates over the embryonal and spindle cell/sclerosing types, followed by the epithelioid and pleomorphic variants. PAX-FOXO1 fusion was observed in 103 cases of alveolar RMS (79.8%). MYOD1 mutation was found in 39 cases of sclerosing/spindle cell RMS (53.4%). FUS/EWSR1-TFCP2 gene fusions were identified in 21 cases of RMS with epithelioid and spindle cell morphologies (95.5%). The 5-year overall survival rate of patients was 61.3%, and MYOD1 mutation correlated with significantly higher mortality.

CONCLUSION

The genotypic profile of histologic variants of HNRMS is widely variable, and MYOD1 mutation could be a potential prognostic factor, but more studies are required to establish this.

Tongue Spindle Cell Rhabdomyosarcoma: A Rare Case Report and Literature Review

Rhabdomyosarcoma (RMS) is a malignant soft tissue neoplasm with its origin in the skeletal muscle and is extremely rare in adults. By the World Health Organization (WHO), a new variant of RMS has been classified, i.e. the spindle cell (Sc) and sclerosing (S) RMS. While the Sc-RMS shows intersecting fascicles of nonpleomorphic spindle cells, the S-RMS is characterized by a marked hyalinization in a pseudovascular growth pattern associated with round-to-spindled tumour cells. According to the analysed data, the Sc/S-RMS variant has a worse outcome than other variants. The new classification of the Sc/S-RMS variant is valuable to the clinical practice. There are not many oral Sc/S-RMS cases reported. The aim of this paper is to demonstrate that an early diagnosis, an adequate treatment and a multidisciplinary approach have a positive effect on the prognosis of the patient. In this study, we analyse a new case of Sc-RMS variant in a young adult with an early diagnosis and a favourable outcome as a result of an appropriated multidisciplinary treatment: early surgery, radiotherapy and chemotherapy treatment.

[Sclerosing rhabdomyosarcoma of the parotid gland: Unusual location of a rare mesenchymal tumor]

Rhabdomyosarcoma is a malignant mesenchymal tumour with skeletal muscle differentiation. Its sclerosing variant is a rare entity, which is described in the latest WHO edition of soft tissues in association with the spindle cell subtype, with which it shares clinical, morphological and cytogenetic features. Cytogenetic advances have allowed a prognostic approach to fusiform/sclerosing cell rhabdomyosarcoma by individualizing 3 different genomic prognostic groups. The parotid location of sclerosing rhabdomyosarcoma is exceptional with only two reported cases in the literature. It can pose a diagnostic challenge because of its rarity and histological similarities with other malignancies. We report the third case of sclerosing rhabdomyosarcoma of the parotid gland, which occurred in a 7-year old girl, who had consulted for a painless swelling of the parotid region of 4 months duration. Gross examination of the partial parotidectomy demonstrated an ill-circumscribed 35×30mm, firm and white glistening tumor. Histologically, it was composed of cords and trabeculae of small round cells, with ovoid and often irregular nuclei. Mitoses were numerous. The cytoplasm was scanty and cell margins were unclear. Tumor cells were set in a prominent hyalinized matrix. Scattered rhabdomyoblastic-like tumor cells were noted. The diagnosis of sclerosing rhabdomyosarcoma was performed after the positive immunostaining with desmin, myogenin and smooth muscle actin. No cytogenetic or molecular studies were performed. The patient underwent adjuvant chemo and radiotherapy, without recurrences or distant metastases during the 8-year follow-up.

Combined Sclerosing and Spindle Cell Rhabdomyosarcoma in Previous Craniotomy Site: A Case Report and a Review of the Literature

Sclerosing rhabdomyosarcoma (RMS) is a rare subtype of RMS with unique prominent stromal hyalinization and a pseudovascular architecture. It overlaps morphologically with spindle cell RMS and poses both diagnostic and therapeutic challenges because of its rarity and aggressive clinical course. In this article, we report a case of sclerosing RMS arising from a prior craniotomy site, which demonstrated both sclerosing and spindle cell components. A literature review of RMS with sclerosing morphology identified 122 cases. Our review documents the following: sclerosing RMS occurs in both childhood and adult populations, has a predilection for the head and neck areas, and has a worse prognosis in adults. Sclerosing RMS harbors a high frequency of MYOD1 mutations, conferring a poor clinical outcome. Sclerosing RMS and spindle RMS likely represent a morphologic spectrum of one entity.

Spindle cell/sclerosing rhabdomyosarcoma with intracranial invasion without destroying the bone of the skull base: a case report and literature review

Spindle cell/sclerosing rhabdomyosarcoma (ssRMS) is a new subtype of rhabdomyosarcoma included in the World Health Organization soft tissue and bone tumor classification in 2013. Despite the increasing number of reported cases of ssRMS, the imaging characteristics of ssRMS are not established. Herein, we present the case of an elderly Japanese woman with ssRMS of the masticator space with intracranial invasion without destruction of the adjacent bone. Attention should be paid to the presence of intracranial infiltration that may indicate a worse prognosis. Tumor growth without bone destruction could be a key finding to differentiate ssRMSs from conventional subtypes of rhabdomyosarcoma.

Rhabdomyosarcoma, Spindle Cell/Sclerosing Variant: A Clinical and Histopathological Examination of this Rare Variant with Three New Cases from the Oral Cavity

Spindle cell/sclerosing rhabdomyosarcoma (S-ScRMS) was recently recognized in 2013 by the World Health Organization (WHO) as a stand-alone entity (Parham et al., WHO classification of tumours of soft tissue and bone, IARC Press, Lyon, 2013). Historically, the spindle cell and sclerosing variants were subcategorized under embryonal type rhabdomyosarcoma. Current data supports that certain S-ScRMS cases have a more aggressive clinical course with reduction of long-term survival, and those found in the head and neck region often exhibit extensive local recurrence. Furthermore, due to variable histopathologic appearances and immunohistochemical findings, misdiagnosis is common. We aim to report the variability in histopathologic patterns, immunohistochemical findings, radiographic features, and clinical data on three new cases of S-ScRMS presenting in the oral cavity of young adult males (ages 22, 24, and 39 years). The English-language literature on S-ScRMS is briefly reviewed as well.

Distinctive Head and Neck Bone and Soft Tissue Neoplasms

Benign and malignant primary bone and soft tissue lesions of the head and neck are rare. The uncommon nature of these tumors, combined with the complex anatomy of the head and neck, pose diagnostic challenges to pathologists. This article describes the pertinent clinical, radiographic, and pathologic features of selected bone and soft tissue tumors involving the head and neck region, including angiofibroma, glomangiopericytoma, rhabdomyosarcoma, biphenotypic sinonasal sarcoma, chordoma, chondrosarcoma, and osteosarcoma. Emphasis is placed on key diagnostic pitfalls, differential diagnosis, and the importance of correlating clinical and radiographic information, particularly for tumors involving bone.

Clinicopathologic analysis of spindle cell/sclerosing rhabdomyosarcoma

BACKGROUND

Clinical characteristics and optimal treatment strategies for spindle cell/sclerosing rhabdomyosarcoma (ssRMS) have not been well established because of its rarity.

PROCEDURE

Retrospective re-evaluation of sarcoma specimens (1997-2014) identified 16 ssRMSs (median age 20 years, range 7-39 years). Clinicopathological features, clinical course, and outcome were analyzed.

RESULTS

Primary disease sites were the head and neck (10 cases) and other regions (6 cases). Nine cases were at Intergroup Rhabdomyosarcoma Study preoperative stage 3. The primary tumors were >5 cm in 13 cases. Two patients had lymph node metastases, but none had distant metastases at presentation. At follow-up (median period 39 months, range 4.6-201), seven patients were alive without disease. Among nine patients treated with the vincristine, actinomycin, and cyclophosphamide (VAC) regimen, five responded well, with four surviving free of disease. Among ten patients with recurrent or progressive disease, three experienced local recurrence, four had distant metastases, and three had both. None exhibited bone marrow invasion. Eight of the ten patients died in median time from relapse to death of 18 months (range 11-56).

CONCLUSIONS

Although most ssRMSs present as a bulky tumor, nodal or distant metastases are rare at presentation. ssRMSs initially show good response to VAC, but >50% of tumors recur or progress; these data suggest a worse prognosis of ssRMS compared to the pediatric embryonal variant. As relapse typically occurs as local or distant solitary lesion without bone marrow invasion, localized treatment combined with chemotherapy would contribute to improve the prognosis of recurrent ssRMS.

Needle biopsy of mesenchymal lesions of the head and neck: Evolving concepts and new strategies for diagnosis

Sarcomas are a rare and heterogeneous group of neoplasms that can be a significant diagnostic challenge in routine practice. Recent advances in the understanding of molecular mechanisms underlying oncogenesis have led to an array of novel diagnostic tools. Here we review several sarcomas of the head and neck region, focusing on neoplasms with new molecular findings and highlighting novel diagnostic tools.

Primary sclerosing rhabdomyosarcoma of the scalp and skull: report of a case and review of literature

We present a case of sclerosingrhabdomyosarcoma of the skull in a young male. This is a rare tumor that immunophenotypically shows rhabdomyoid differentiation. The lesion had a moderately aggressive course and the patient died at 19 months after diagnosis.

Pediatric sclerosing rhabdomyosarcomas: a review

Sclerosing RMS (SRMS) is a recently described subtype of RMS that has not yet been included in any of the classification systems for RMSs. We did pubmed search using keywords “sclerosing, and rhabdomyosarcomas” and included all pediatric cases (age ≤ 18 years) of SRMSs in this review. We also included our case of an eleven-year-old male child with skull base SRMS and discuss the clinical, histopathological, immunohistochemical, and genetic characteristics of these patients. Till now, only 20 pediatric cases of SRMSs have been described in the literature. Pediatric SRMS more commonly affects males at a mean age of 9 years. Extremeties and head/neck regions were most commonly affected. Follow-up details were available for 16 patients with mean follow-up of 25.3 months. Treatment failure rate was 43.75%. Overall amongst these 16 patients, 10 were alive without disease, 4 were alive with disease, and two died. Thus, overall and disease-free survival amongst these 16 patients were 87.5% and 62.5%, respectively. The literature regarding clinical behaviour and outcome of pediatric patients with SRMSs is patchy. Detailed molecular/genetic analysis and clinicopathological characterization with longer follow-ups of more cases may throw some light on this possibly new subtype of RMS.

Sclerosing rhabdomyosarcoma: presentation of a rare sarcoma mimicking myoepithelial carcinoma of the parotid gland and review of the literature

Sclerosing rhabdomyosarcoma (SRMS), a recently characterized variant of rhabdomyosarcoma, can pose a significant diagnostic challenge given its rarity and its histological similarity to other malignancies. SRMS is characterized by dense hyalinized or sclerosing collagenous matrix and a pseudovascular pattern of growth. SRMS shares histologic similarities with several mesenchymal tumors including: leiomyosarcoma, osteosarcoma, chondrosarcoma, angiosarcoma, and sclerosing epithelioid fibrosarcoma. We herein report a case of SRMS mimicking a myoepithelial carcinoma of the parotid gland. The tumor contained small, spindled, and epithelioid tumor cells lining pseudovascular spaces within a dense hyalinized stroma. Initial stains for keratins, S100 and p63 were negative. However the tumor cells showed desmin and myogenin positivity. The tumor was negative for FKHR gene rearrangements and showed no MDM2 gene amplification. This is the second case of SRMS to be diagnosed in the parotid gland highlighting the potential for misdiagnosis as a primary salivary gland epithelial malignancy.

Sclerosing rhabdomyosarcoma presenting in the masseter muscle: a case report

Abstract

Sclerosing rhabdomyosarcoma (SRMS) is exceedingly rare, and may cause a great diagnostic confusion. Histologically, it is characterized by abundant extracellular hyalinized matrix mimicking primitive chondroid or osteoid tissue. So, it may be easily misdiagnosed as chondrosarcoma, osteosarcoma, angiosarcoma and so on. Herein, we report a case of SRMS occurring in the masseter muscle in a 40-year-old male. The tumor showed a diverse histological pattern. The tumor cells were arranged into nests, cords, pseudovascular, adenoid, microalveoli and even single-file arrays. Immunostaining showed that the tumor was positive for the Vimentin, Desmin and MyoD1, and was negative for CK, P63, NSE, CD45, CD30, S-100, CD99, Myoglobin, CD68, CD34, CD31, and α–SMA. Based on the morphological finding and immunostaining, it was diagnosed as a SRMS. In addition, focally, our case also displayed a cribriform pattern resembling adenoid cystic carcinoma. This may represent a new histological feature which can broaden the histological spectrum of this tumor and also may lead to diagnostic confusion.

Virtual slides

The virtual slide(s) for this article can be found here: http://www.diagnosticpathology.diagnomx.eu/vs/1615846455818924