BACKGROUND: Alveolar soft part sarcoma is a rare tumour of soft tissues, mostly localized in muscles or deep soft tissues of the extremities. In rare occasions, this tumour develops in deep tissues of the abdomen or pelvis.
METHODS: In this case report, we described the case of a 46 year old man who developed a primary splenic alveolar soft part sarcoma. The tumour displayed typical morphological alveolar aspect, as well as immunohistochemical profile notably TFE3 nuclear staining. Detection of ASPSCR1 Exon 7::TFE3 Exon 6 fusion transcript in molecular biology and TFE3 rearrangement in FISH confirmed the diagnosis.
CONCLUSIONS: We described the first case of primary splenic alveolar soft part sarcoma, which questions once again the cell of origin of this rare tumour.

UNASSIGNED: Alveolar soft part sarcoma (ASPS) is a rare and distinct subtype of soft tissue sarcoma. This study aims to describe the unique presentation of ASPS in the female genital tract.
UNASSIGNED: Prognostic factors for cancer-specific overall survival (CSS) were evaluated using multivariate analyses.
UNASSIGNED: In our case series, we identified a novel TFE3-PRCC gene fusion in a 24-year-old unmarried patient with cervical ASPS who underwent fertility-sparing surgery and remained recurrence-free for 41 months. The other two patients underwent radical hysterectomy and bilateral salpingo-oophorectomy. At the time of writing, the two patients had been disease-free for 49 and 71 months, fluorescence in situ hybridization showed break-apart signals for the ASPL-TFE3 gene. Among the 55 cases with available information from the PubMed/Medline database, most presented with localized disease, and at the last follow-up, all patients were alive and 45 patients showed no evidence of disease. The 5-year CSS rate in the female genital tract cohort from SEER database was 86.2%. Multivariate analysis revealed that older age was associated with a 1.042-fold increased risk of cancer-specific mortality (HR=1.042, 95% CI 1.022-1.063, P < 0.001), involvement of soft tissue including the heart was associated with a 4.786-fold higher risk (HR=4.7868, 95% CI 1.681-13.623, P= 0.003), and regional infiltration and distant metastasis were associated with approximately 8.6-fold and 18-fold higher risk of cancer-specific mortality compared to local disease, respectively (HR=8.652, 95% CI 2.529-29.63, P = 0.001; HR=18.366, 95% CI 6.153-54.817, P< 0.001). Patients who underwent radical excision did not show reduced cancer-specific mortality compared to those who underwent local excision (HR=0.492, 95% CI 0.224-1.081, P = 0.078).
UNASSIGNED: Previously unrecognized genetic diversity exists in ASPS. Patients with ASPS in the female genital tract have the lowest likelihood of presenting with a distant disease and are associated with a more favorable survival outcome.

BACKGROUND: Primary uterine alveolar soft part sarcoma (ASPS) is a rare, indolent mesenchymal malignancy with less than 40 patients documented in the literature.
METHODS: We report an example of ASPS in a 61-year-old postmenopausal woman. Macroscopically, the uterus showed multiple nodular masses. Microscopic examination revealed tumor arranged in nests and alveolar pattern. The tumor cells were moderately to markedly pleomorphic, epithelioid to polygonal, with eccentrically placed nuclei, vesicular chromatin, prominent macro-nucleoli, and moderate to abundant eosinophilic cytoplasm. PAS-positive and diastase-resistant intracytoplasmic crystals were also seen in some tumor cells. On immunohistochemistry, the tumor cells showed diffuse positivity for vimentin and nuclear positivity for TFE3, a surrogate marker for ASPS. These were negative for SMA, desmin, CD10, h-caldesmon, cyclin D1, EMA, Melan A, and CD34. SMARCB1 expression was retained. Based on the histopathology and IHC, a final diagnosis of uterine ASPS was rendered.
CONCLUSIONS: Knowledge of the characteristic histopathologic and immunohistochemical features can help accurately diagnose such rare tumors. Knowledge of the characteristic histopathologic and immunohistochemical features can help accurately diagnose such rare sarcoma in an uncommon site with an unusual age.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a very rare mesenchymal malignancy of uncertain origin. It mostly affects young people, with about a quarter of cases being diagnosed in children.
METHODS: An 11-year-old girl had a painless subcutaneous \"lump\" in the left elbow area. Imaging exams revealed a solid soft-tissue intramuscular mass of suspicious appearance. A surgical excision of lesion was performed. The biopsy consisted of a lobular tumor measuring 35 × 20 × 12 mm. Histology revealed an epithelioid-cell population arranged in organoid pseudoalveolar pattern. It immunohistochemically expressed TFE3 and harbored the ASPSCR1:: TFE3 gene fusion. A diagnosis of ASPS was established. Subsequently, a wide re-excision of the scar was performed without microscopic residual tumor. The patient is currently without evidence of local recurrence or metastasis.
CONCLUSIONS: ASPS is considered an aggressive and prognostically unfavorable chemoresistant neoplasm. Children have a better prognosis compared to adults. Early detection of tumor in a localized stage with complete surgical removal remains a mainstay therapeutic option. Due to its tendency to late metastases, a long-term thorough follow-up of the patient is necessary.

OBJECTIVE: Female genital alveolar soft part sarcoma (ASPS) is rare and has a favourable prognosis compared to ASPS from other sites. We reported our experience to manage a case with uterine corpus ASPS (UC ASPS) and conducted a literature review on prognosis of ASPS from different sites of female genital tract.
METHODS: This report represented a 33-year-old woman who had UC ASPS. She received tumor excision with uterine preservation and had the longest follow-up time (155 months) without recurrence in the literature.
CONCLUSIONS: UC ASPS has better prognosis than ASPS from the uterine cervix, the low uterine segment, vulvovaginal area and perineum. We recommended conservative treatment for young women with UC ASPS.

Alveolar soft part sarcoma (ASPS) is an extremely rare type of soft tissue sarcoma. The primary sites of ASPS are mostly located in the extremities and trunk. Primary pulmonary ASPS is extremely rare. A search of the PubMed® database identified only five cases of primary pulmonary ASPS. This current case report describes the sixth case of ASPS in a 15-year-old male that presented with recurrent headaches. Head computed tomography showed space-occupying lesions in the left parietal lobe. Positron emission tomography-computed tomography confirmed the space-occupying lesions in the left parietal lobe and showed multiple nodules and masses in the two lungs and pleura, which were considered to be low-grade malignant mesenchymal tumours. The case report presents the clinical characteristics, diagnosis and treatment process. Programmed cell death protein 1 monoclonal antibody (sintilimab) combined with a tyrosine kinase inhibitor (anlotinib hydrochloride) achieved a good therapeutic effect, indicating that this combination therapy is worth exploring further. Large-scale prospective studies are needed to explore and develop standardized treatments for ASPS.

Alveolar soft part sarcoma (ASPS) is a rare malignancy that is morphologically characterized by a distinctive nodular, organoid, or nested growth pattern in which the cells are separated by vascularized septa. The diagnosis is based on a combination of pathologic and immunohistochemical findings and the presence of an ASPSCR1-TFE3 gene fusion revealed by next-generation sequencing. ASPS most commonly occurs as a painless mass in the lower extremity, with likely involvement in the lungs if metastasis is present. Here we report a case of ASPS that exhibited the characteristic ASPSCR1-TFE3 gene fusion along with a reciprocal fusion of TFE3-ASPSCR1, which presented in the nasolabial fold of a 31-year-old female. An intraoral approach was utilized for complete surgical resection of the malignancy, resulting in continued remission after 11 months.

NTRK-rearranged spindle cell neoplasms (NTRK-RSCNs) are a new category of soft tissue tumors with NTRK gene fusions. The present study aimed to investigate the radiological features of NTRK-RSCNs and their association with histopathological findings. The present study included six patients with NTRK-RSCNs, whose fusion genes were confirmed using next-generation sequencing. All patients underwent surgery, and their diagnosis and clinical outcomes were investigated. In addition, the magnetic resonance imaging (MRI) features of all tumors and histopathological findings of the resected specimens were assessed. The present study included three women and three men, with a mean age of 22 years (range, 2-43 years). The NTRK gene fusions included four NTRK1 and two NTRK3 fusions. Three patients were preoperatively diagnosed with solitary fibrous tumors. One patient with NTRK3 fusion experienced local recurrence and distant metastases, whereas the other five patients had no local recurrence or metastasis. MRI revealed that all tumors were highly vascular with intra- and peritumoral flow voids of differing degrees. Furthermore, a partially ill-defined border, suggesting infiltration of tumors into the surrounding tissues, particularly fat tissue, was observed in five patients, which was confirmed by histopathological findings. In conclusion, NTRK-RSCNs are highly vascular tumors that can infiltrate the surrounding tissues. These findings suggested that NTRK-RSCNs should be considered in the differential diagnosis of highly vascular-rich mesenchymal tumors, including solitary fibrous tumors and alveolar soft part sarcomas. Furthermore, wide resection may be preferred to completely resect this type of tumor, considering its invasive nature.

BACKGROUND: Alveolar soft part sarcoma (ASPS) is a rare kind of malignant soft tissue tumor with undefined differentiation, of which the incidence rate accounts for only 0.5-1.0% among all kinds of soft tissue tumors. An even rarer ASPS occurs in kidney.
METHODS: Here we reported a case of a 7-year-old girl diagnosed with nephrogenic ASPS, regarding the analyses of the incidence, clinical manifestation, pathology and genetic diagnosis, in order to deepen the recognition of the disease.
CONCLUSIONS: ASPS is very rare, and tends to occur to young patients. It is very significant to precisely diagnose ASPS at an early stage, which will be the key point for the following treatment choices and prognosis.

BACKGROUND: Myositis ossificans circumscripta is a self-limiting, benign, ossifying lesion that can affect any type of soft tissue. It is most commonly found in muscles as a solitary lesion. A history of recent trauma has been reported in approximately 50% of cases. Clinically, MOC presents as a painful swelling, which rapidly increases in size. The pain and inflammatory symptoms spontaneously disappear after approximately 2-6 weeks, and the mass stabilizes or decreases. Radiologically, myositis ossificans circumscripta can be divided into two phases. The first is the acute phase, which is followed by the mature phase 2-6 weeks later. During the acute phase, the radiological aspect does not show any specific abnormality. In the mature phase, plain radiographs and computed tomography show blurred calcifications around a hypodense center. We describe here the first case of myositis ossificans circumscripta, with appropriate follow-up, occurring during sunitinib exposure.
METHODS: We report a case of myositis ossificans circumscripta in a 34-year-old man (ethnicity unknown) receiving sunitinib for metastatic alveolar soft part sarcoma of the left thigh after surgery and radiotherapy. Four months after the first dose of sunitinib, the patient experienced painful swelling in the surgical scar area. Magnetic resonance imaging showed diffuse and marked edema of the anterior compartment of the thigh, without nodular lesions circumscribing a central core, and without bone signal abnormality. The increased visibility of the intermuscular fascia and convergence of normal muscle fibers (black hole effect), without the displacement seen in tumors, were suggestive of myositis. Therefore, antiangiogenic treatment was discontinued, and the symptoms rapidly resolved within a few days. Three weeks after the discontinuation of sunitinib, the inflammatory findings completely disappeared. Two months after the diagnosis of myositis ossificans circumscripta, plain radiographs and computed tomography showed an extensive calcified mass measuring > 12 cm. The continuation of favorable clinical outcomes was confirmed.
CONCLUSIONS: To the best of our knowledge, this is the first case of myositis ossificans circumscripta with appropriate follow-up occurring during sunitinib exposure. Owing to multimodal treatment of sarcoma, we cannot rule out the radiotherapy and surgery causality.