A 47-year-old man presented to our referral center in November 2017, with a history of EMC of the right shoulder improperly excised with unplanned microscopic positive surgical margins (R1). The patient underwent debulking of the primary mass in September 2017 in a non-referral center, without a preoperative core-needle biopsy. The histological examination diagnosed EMC. No post-operative treatments were provided. At our first evaluation, the patient did not show macroscopic residual disease or distant metastasis both at the clinical and the radiological assessment. The pathological review of the excised specimen confirmed the diagnosis of EMC. After MTB discussion a “watch and wait” approach was adopted. After a 4-months follow-up, the clinical examination showed an elastic soft painless mass in the right shoulder. A Magnetic Resonance Imaging (MRI) of the shoulder was performed, showing a 35 × 15 mm intramuscular solid mass (Fig. ) within the right deltoid muscle. Computed Tomography (CT) did not reveal distant metastasis. The case was discussed in our MTB where the decision was made for preoperative RT, with a total dose of 50 Gy (fractionated in 200 cGy/die) which was a administered with Rapidarc technique. Post radiotherapy MRI performed 3 weeks later showed a partial radiological response, with a mass measuring 16 × 6 mm (Fig. ).\nIn July 2018, a wide surgical resection including the right anterior deltoid muscle and the lateral margin of the right pectoralis major muscle was performed, with a planned macroscopic margin of minimum 3 cm and the complete excision of the scar and the field of the previous surgery. The defect was reconstructed by right latissimus dorsi myocutaneous flap and polypropylene prosthesis (Figs. and ).\nThe size of the excised specimen was 23.5 × 10 × 3.5. Pathological examination was negative for viable tumor cells, showing only a fibrous subcutaneous scar. The patient had a complete response to preoperative RT. After MTB discussion, no further adjuvant treatments were provided. The patient did not show postoperative complications and was discharged on postoperative day 5. Neither relapse or systemic progression occurred in 24-months post-operative follow up. After the surgery the patient wore a shoulder brace for 15 days to avoid damage to the flap. Then a rehabilitation program consisting of 24 sessions (three times a week, lasting 1 h a session) was performed to improve the range of motion of the shoulder and motor performance of the shoulder girdle. No functional deficits were observed 6 months after surgery and at the 24-month follow up. Currently, after 2 years from surgery, at the clinical evaluation, the patient does not show differences in the flexion and abduction of the shoulder between right and left side (Fig. and ) and he confirms that he is leading a normal life without experiencing functional deficit or limitations in his daily life and his professional activities.
A 13-year-old male presented with a rapid enlarging painless diffuse mass located at the right midface and parotid region over the last 6 months. Slight asymmetry of the right commissure, trismus and mandibular asymmetry were evident on initial examination. There were no evidences of regional or distant metastasis. Past medical history included a previous surgical treatment attempt in his native country Honduras, three months prior to his referral (Fig. A). T1 weighted MRI showed a large hyperintense mass measuring 7 x 5 cm, located centrally at the right masticator space with extention into the mandibular ramus, masseter and pterigoyd muscles, parotid gland and parapharyngeal space. Contrast T2 weighted MRI exhibited a high signal with a multinodular and infiltrative pattern (Fig. B).\nAn incisional intraoral biopsy was performed under local anesthesia. The histopathological examination revealed multiple nodules containing tumor cells, immersed in an abundant myxoid stroma separated by fibrous septae. The tumor cells varied in shape from round to elongate, most displaying abundant eosinophilic cytoplasm and round to ovoid excentrically located nuclei, which showed homogeneously distributed chromatin and inconspicuous nucleoli. Other cell types were recognized, mainly spindle, epithelioid and lipoblast-like cells (Fig. ). The mitotic rate was low, averaging two mitotic figures per 10 high-power fields. Periodic acid-Schiff (PAS), with and without prior diastase digestion, demonstrated that the granular cytoplasmic material was glycogen. Immunohistochemical analysis (), showed positivity for vimentin, neuron-specific enolase (NSE), and chromogranin; whereas AE1/AE3, epithelial membrane antigen (EMA), S-100, desmin, muscle-specific actin (HHF35), CD57, Glucose transporter type 1 (Glut-1), synaptophysin, p53, p63, glial fibrillary acidic protein (GFAP), and podoplanin (D2-40) were negative. The Ki-67 labelling index was 42% after evaluation of 1000 cells per five high-power fields (Fig. ). Fluorescent in situ hybridization was not performed; however, the histomorphological and immunohistochemical findings supported a final diagnosis of EMC.\nThere were no evidences of regional or distant metastases, and the patient was treated with en-bloc surgical resection, including ipsilateral hemi-mandibulectomy, total parotidectomy with facial nerve dissection, neck dissection level I to IV and reconstruction with a mandibular plate and major pectoralis flap. Macroscopically, the specimen measured 8 x 6 x 5 cm consisting of an irregularly shaped mass attached to the mandibular ramus, with a multilobular and gelatinous rubbery tissue. Focally, the tumor was present in one surgical margin, immediately anterior to the mandibular condyle. Microscopic evaluation revealed the same histopathological features found in the incisional biopsy. The patient received adjuvant radiotherapy but died after 1 year of follow-up due to complications of locoregional tumor dissemination to the skull base.