BACKGROUND: Rhabdomyosarcoma, though rare in the middle ear, necessitates prompt recognition for optimal management. They are malignant mesenchymal neoplasms arising from the embryonic mesenchymal cells of striated skeletal muscles.
METHODS: We present a case of a 5-year-old child with massive right mastoid swelling and bloody ear discharge. Cytological examination via fine needle aspiration biopsy revealed features suggestive of a malignant mesenchymal tumor, confirmed on imaging and subsequent histopathology as embryonal rhabdomyosarcoma (ERMS) FNCLCC grade 2. Characteristic cytological findings included spindle-shaped cells in a myxoid stroma with tigroid background, aiding in early diagnosis. Despite radical mastoidectomy and adjuvant chemotherapy, ERMS in the middle ear remains challenging due to its aggressive nature and potential complications.
CONCLUSIONS: This case underscores the importance of cytological evaluation in identifying rare soft tissue tumors like ERMS, facilitating timely intervention and improved outcomes. Early recognition and multidisciplinary management are crucial in addressing the complexities of ERMS in uncommon sites like the middle ear.

Synovial sarcomas (SSs) are a rare group of malignant tumors originating from pluripotential mesenchymal cells, which commonly occur as the primary tumor in the soft tissues near the articular surface, tendons, and articular synovium. Herein, we report a rare case of mediastinal SS in an 18-year-old teenager who initially presented with cough as the primary symptom. In this case, plain chest CT and contrast-enhanced CT clearly revealed the lesion presenting as a round-like and uneven density mass in the mediastinum with heterogeneous enhancement, which compressed the trachea and invaded the adjacent vessels. Based on the results of immunohistochemistry and fluorescence in situ hybridization (FISH), combined with the differential diagnosis with other types of tumors in the mediastinum on imaging, we were able to diagnose the tumor as an SS located in the mediastinum. Subsequent resection of the lesion coupled with chemotherapy and immunotherapy led to an improvement in the patient\'s symptoms.

Macrodystrophia lipomatosa (MDL) is a rare disorder characterized by overgrowth of mesenchymal cells, resulting in gigantism of one or more digit. We report a case of a woman in her late 60s who presented with abnormal enlargement of the right second toe. By debulking the pathological tissue while preserving the shape of the toe as much as possible without amputation of the entire phalanx, debulking surgery not only helps walking, but also allows wearing shoes of the same size on both feet and achieves cosmetic satisfaction for patients. The functional and cosmetic improvement obtained through debulking surgery in this case resulted in no recurrence of disease 5 years postoperatively and provided a desirable alternative to amputation. Therefore, through this case, we demonstrated that debulking surgery can be a reasonable option for MDL patients.

Congenital epulis is an unusual benign oral mucosal lesion in newborns with no tendency to recur after excision. The histogenesis of the lesion is unknown, but it is believed to be of mesenchymal origin. We describe a case of congenital epulis (20×10 mm) in the mandibular gingiva of a newborn. The mass, which was smooth-surfaced and pedunculated with a healthy color, was surgically removed at 5 months post-birth. Histologically, the tumor consisted mainly of large eosinophilic granular cells. Immunohistochemical studies revealed intense staining for vimentin, STRO-1, and CD44, suggesting that it was derived from mesenchymal cells. The literature and immunohistochemical profile of congenital epulis are also discussed.