Rhabdomyosarcoma of lip - issues of subtyping, morphology and immunohistochemistry versus molecular studies: a case report with review of literature

Rhabdomyosarcoma (RMS) is a malignant soft tissue tumour occurring most frequently in younger age groups. Study presented a rare case of spindle cell Rhabdomyosarcoma of the upper lip involving the commissure area. In this case report after successful surgical excision, the patient underwent extensive postoperative histopathological studies including special stains and immunohistochemistry. Genotype studies (reverse transcription polymerase chain reaction) were done to help in subtyping and prognostication, and it turned out to be a surprise as it showed positivity for PAX3-FOXO1 t (2;13) translocation which is almost exclusively seen with alveolar RMS. After that he successfully underwent chemotherapy and radiotherapy as it was an aggressive variant and has been disease free for the past 2 years. The author hopes that this case report will highlight the importance of high clinical suspicion in head and neck masses presenting in pediatric age group and to not rely solely on biopsy reports to confirm diagnosis, so that early detection will lead to successful therapy and outcome as exemplified in this case.

Primary Rhabdomyosarcoma of the Breast: Study of Three Cases at One Institution with a Review of Primary Breast Sarcomas

BACKGROUND: Primary breast sarcoma (PBS) is rare, comprising approximately 1% of breast malignancies. Rhabdomyosarcoma (RMS) accounts for an extremely small proportion of PBSs, often leading to delayed histologic confirmation. METHODS: Upon reviewing Asan Medical Center’s pathology database between 2000 and 2018, 41 PBS cases were retrieved, including three cases of primary RMS of the breast. Their clinicopathological features were analyzed, and the literature related to PBS and primary RMS of the breast was reviewed. RESULTS: We identified three primary breast RMS cases from our institution database, comprising 7.3% of PBS: one case each of spindle cell/sclerosing RMS (ssRMS), alveolar RMS (aRMS), and embryonal RMS (eRMS). All cases involved adolescents or young adults (14, 16, and 25 years, respectively) who underwent mastectomy or radiotherapy and were confirmed using immunohistochemical testing for myogenin, desmin, and myogenic differentiation. The ssRMS patient experienced recurrence at the operation site 4 months post-surgery despite undergoing concurrent chemoradiotherapy. The aRMS patient had multiple metastases at diagnosis and showed FAX3-FOXO1 fusion transcripts; she died 22 months after the diagnosis. The eRMS patient had enlarged axillary lymph nodes; post-radiotherapy, the lesion recurred as multiple metastases to the bone and lung. She died 18 months post-diagnosis. CONCLUSIONS: Our experience on RMS cases suggests that spindle cell or small round cell malignancy in breasts of young female should raise suspicion for the possibility of primary or secondary RMS. To our knowledge, this is the second report of primary breast ssRMS and it may help clinicians who encounter this rare disease in the future.

Clinicopathological features of three cases of spindle cell rhabdomyosarcoma and review of literatures / 临床与实验病理学杂志

Purpose To investigate the clinicopathological characteristics and differential diagnosis of spindle cell rhabdomyosarcoma ( SCRM) . Methods Three cases of SCRMs were analyzed by gross examination, microscopy and immunohistochemistry. Relevant lit-eratures were reviewed to summarize the diagnostic features of SCRM and its differential diagnosis. Results All the 3 cases were male infants aged from 2 days to 4 years. 2 cases were located in paratesticular and 1 in back. Tumors were all well-circumscribed but unen-capsulated, with white-gray cut surface, firmed and sized 2. 0 to 6. 0 cm in diameter. Histologically, tumors displayed invasive growth but were well-circumscribed. Tumor cells were spindle to round with eosinophilic cytoplasm and fascicular, storiform, wavy appear-ance. Horizontal structure and striated muscle brood cells were observed in some cells or local regions. A small amount of collagen fi-brils were observed in the mesenchymal components. The nucleus were long or fine wavy with unconspicuous nuclear atypia, mitosis could be occasional observed. Immunohistochemically, tumor cells were positive for vimentin, desmin, myogenin and MyoD1. CK,α-inhabin, AFP, CD34 and S-100 were negative. Conclusions SCRM is a rare and new type of rhabdomyosarcoma that commonly oc-curred in infant. It should be differentiated from other tumors, such as infantile fibromatosis, congenital fibrosarcoma, fibrosarcoma, leiomyosarcoma, triton tumor, malignant melanoma of promoting the fibrous tissues.