Rhabdomyosarcoma of the maxillary gingiva

Gingival rhabdomyosarcoma mimicking a non-neoplastic proliferative lesion: A diagnostic challenge

Rhabdomyosarcoma (RMS) is a soft tissue sarcoma that develops from skeletal striated muscle cells. RMSs are exceedingly rare in the oral cavity, particularly in the gingiva. Herein, we reported the clinicopathological and immunohistochemical features of a rare case of RMS in a 30-year-old female presenting clinically as a painful polypoid nodule on the mandibular gingiva. Microscopically, the tumor showed atypical spindle cells with elongated nuclei and eosinophilic cytoplasm arranged in a fascicular pattern. In focal areas, the tumor cells exhibited rhabdomyoblastic differentiation. Immunohistochemistry showed strong positivity for desmin, myogenin (scattered cells), and MyoD1. The patient underwent surgical resection followed by postoperative complementary radio- and chemotherapy. However, the patient had a local recurrence seven months after the initial treatment. She was submitted to a total mandibulectomy associated with adjuvant radiotherapy. However, she died two months after reoperation due to complications secondary to radiation therapy. Because of the rarity in the oral cavity and non-specific signs and symptoms, the clinical diagnosis of RMS is difficult and often overlooked. Therefore, careful histopathological and immunohistochemistry analysis of these tumors is essential to correct diagnosis. Early surgical excision with tumor-free margins and prolonged follow-up are strongly recommended.

CDK1 and CCNB1 as potential diagnostic markers of rhabdomyosarcoma: validation following bioinformatics analysis

Background

Rhabdomyosarcoma (RMS), a common soft-tissue malignancy in pediatrics, presents high invasiveness and mortality. However, besides known changes in the PAX3/7-FOXO1 fusion gene in alveolar RMS, the molecular mechanisms of the disease remain incompletely understood. The purpose of the study is to recognize potential biomarkers related with RMS and analyse their molecular mechanism, diagnosis and prognostic significance.

Methods

The Gene Expression Omnibus was used to search the RMS and normal striated muscle data sets. Differentially expressed genes (DEGs) were filtered using R software. The DAVID has become accustomed to performing functional annotations and pathway analysis on DEGs.

The protein interaction was constructed and further processed by the STRING tool and Cytoscape software. Kaplan–Meier was used to estimate the effect of hub genes on the ending of sarcoma sufferers, and the expression of these genes in RMS was proved by real-time polymerase chain reaction (RT-PCR). Finally, the expression of CDK1 and CCNB1 in RMS was validated by immunohistochemistry (IHC).

Results

A total of 1932 DEGs were obtained, amongst which 1505 were up-regulated and 427were down-regulated. Up-regulated genes were largely enriched in the cell cycle, ECM-receptor interaction, PI3K/Akt and p53 pathways, whilst down-regulated genes were primarily enriched in the muscle contraction process. CDK1, CCNB1, CDC20, CCNB2, AURKB, MAD2L1, HIST2H2BE, CENPE, KIF2C and PCNA were identified as hub genes by Cytoscape analyses. Survival analysis showed that, except for HIST2H2BE, the other hub genes were highly expressed and related to poor prognosis in sarcoma. RT-PCR validation showed that CDK1, CCNB1, CDC20, CENPE and HIST2H2BE were significantly differential expression in RMS compared to the normal control. IHC revealed that the expression of CDK1 (28/32, 87.5%) and CCNB1 (26/32, 81.25%) were notably higher in RMS than normal controls (1/9, 11.1%; 0/9, 0%). Moreover, the CCNB1 was associated with the age and location of the patient’s onset.

Conclusions

These results show that these hub genes, especially CDK1 and CCNB1, may be potential diagnostic biomarkers for RMS and provide a new perspective for the pathogenesis of RMS.

Rhabdomyosarcoma involving maxilla mimicking gingival enlargement: A diagnostic challenge

Rhabdomyosarcoma (RMS) is a rare, rapidly growing, highly aggressive malignant neoplasm, originating from undifferentiated mesenchymal cells that retain their ability to differentiate into skeletal muscle. It mainly affects children, accounts for <1% of all adult malignancies and has varied clinical presentations. The head and neck region accounts for 35%-40% of all RMS cases, of which 10%-12% cases involve the oral cavity. This report deals with a case of RMS in a 40-year-old woman, primarily involving maxillary gingiva for which she underwent excision with subsequent recurrences. The uniqueness of this case is that it reminds us of the essential clinical dictum that 'every growth we encounter, no matter how benign it appears clinically, should be looked upon with suspicion'. Hence, proper integration of history, clinical examination and investigation is required to reach a correct diagnosis enabling early treatment, thereby preventing functional and aesthetic loss and psychological trauma.

Embryonal Rhabdomyosarcoma (Botryoid Subtype) Affecting the Buccal Mucosa

Rhabdomyosarcoma (RMS) is a rare oral malignant soft tissue tumor whose pathological features may influence the clinical behavior, treatment and prognosis of the lesion. We report a case of a 13-year-old female patient, presenting an asymptomatic polypoid swelling in the left buccal mucosa that was approximately 2.5 cm in diameter and 3 months evolution. The presumptive diagnosis was fibrous hyperplasia and an excisional biopsy was carried out. Pathologic analysis revealed proliferation of predominantly ovoid cells, with eosinophilic cytoplasm and pleomorphic nuclei, arranged in subepithelial cambium layer. The mucosal surface presented a papillary-verrucous appearance. Immunohistochemical analysis revealed intense positivity for desmin, myogenin and Ki-67. The diagnosis was of embryonal RMS (botryoid variant). The patient was subjected to complementary chemotherapy and radiotherapy, with no evidence of recurrence or metastatic disease after 12 months follow-up. A discussion on the clinical, histopathological, immunohistochemical and therapeutic aspects of botryoid RMS will be provided.