Myoepithelial and oral intracranial myxoid mesenchymal tumor-like neoplasms as diagnostic considerations of the ever-expanding extracranial myxocollagenous tumors harboring FET-CREB fusions.

AIMS: Intracranial myxoid mesenchymal tumors (IMMTs) with fusions between EWSR1/FUS and CREB transcription factors have morphologic overlap with myxoid angiomatoid fibrous histiocytoma (mAFH) and myoepithelial tumor/carcinoma (MET/MEC). We aimed to study the clinicopathologic and genetic spectrum of extracranial IMMT-like tumors and their relationships with mAFH and MET/MEC. METHODS: Twelve extracranial tumors harboring EWSR1/FUS-CREB fusions across different histologic groups were characterized using RNA sequencing, FISH and/or RT-PCR. RESULTS: There were 4 IMMT-like neoplasms, 3 MET/MECs, and 5 mAFHs from the tibia (n=1), oral cavity (n=2), and soft tissues (n=9; 5 in the extremities), harboring EWSR1-ATF1 in 4 cases, FUS-CREM and EWSR1-CREM in 3 each, and EWSR1-CREB1 in 2. Multinodular growth, reticular/cording/trabecular arrangements, myxocollagenous matrix, and lymphocytic infiltrates variably prevailed among the 3 groups. mAFHs were characterized by cells with syncytial cytoplasm. IMMT-like neoplasms and MET/MECs shared cells with distinct boundaries, but only MET/MECs expressed GFAP and/or S100. MUC4 and ALK were expressed in some IMMT-like neoplasms (2/4; 2/4) and mAFH (2/5; 1/5). Pan-TRK reactivity was observed in two IMMT-like neoplasms with upregulated NTRK3 mRNA and one MEC. Local recurrences, typically ≥ 12 months postoperatively, developed in 2/3 IMMT-like neoplasms, 1/2 MET/MECs, and 0/4 mAFHs with follow-up. No definite associations were found between fusion types and histology, immunoprofile or outcome. CONCLUSIONS: We demonstrated the similarities and differences among 3 extracranial myxocollagenous tumor groups sharing EWSR1/FUS-CREB fusions. Oral IMMT-like neoplasms harboring FUS-CREM or EWSR1-ATF1 and FUS-CREM-positive.

The Extracompartmental Tumoral Invasion of Extraskeletal Myxoid Chondrosarcoma Induces Distant Metastasis.

BACKGROUND: Extraskeletal myxoid chondrosarcoma (EMC) is a rare malignant soft-tissue tumor and often shows extracompartmental tumoral invasion. The aim of our study was to investigate the clinical features, especially extracompartmental tumoral invasion (ETI) of EMC. PATIENTS AND METHODS: A total of 35 operative patients diagnosed with EMC were enrolled in this study from January 1980 to March 2018 in the Cancer Institute Hospital of The Japanese Foundation for Cancer Research. The operative procedure was principally wide excision. Univariate analysis assessed how clinicopathological factors (e.g. age, gender, tumor site, tumor size, histopathological grade, surgical margin, metastasis before operation, barrier invasion, local recurrence, metastasis after operation) influenced patient prognosis. We assessed how clinicopathological factors influenced ETI of EMC. RESULTS: Among 35 patients, 10 patients showed ETI. The average follow-up was 5.57 (range=0.2-20 years). The 5- and 10-year overall survival was 91.3% and 71.2%, respectively. The 5- and 10-year overall survival of patients with M0 disease was 96.1% and 73.2%, respectively, while both were 75.0% for those with M1 disease, respectively. The patients with distant metastasis at first visit tended to have a poor prognosis (p=0.07). It is notable that all of the 10 patients with ETI had distant metastasis after surgery. CONCLUSION: Patients with distant metastasis at first visit tended to have a poor prognosis. ETI of EMC induced distant metastasis after surgery. Patients with ETI of EMC should, therefore, be carefully monitored over a prolonged period.

A case of diffuse infiltrating gastrointestinal stromal tumor of sigmoid colon with perforation.

Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, and typically present as discrete well-circumscribed but non-encapsulated tumor masses. In this report, we describe a case of colonic perforation caused by an unusual form of GIST. A 72-year-old Japanese woman presented to the emergency department with acute abdominal pain. Under the provisional diagnosis of sigmoid colon perforation, a laparoscopic sigmoidectomy was performed. Although the tumor mass was undetectable during the preoperative examination, a spindle cell lesion with a diffuse longitudinal growth pattern replacing the muscularis propria was revealed by microscopic examination. The spindle cell lesion was exposed at the perforation, suggesting a causal relationship between the lesion and the perforation. The spindle cell lesion was KIT-positive and had a mutation in the C-KIT gene at exon 11. We diagnosed it as diffuse infiltrating GIST. We consider that the lesion would be a cause of the colonic perforation, and emphasize the importance of accurate diagnosis of the lesion by histological, immunohistochemical and genetic examinations.

Second cranio-facial malignancies in hereditary retinoblastoma survivors previously treated with radiation therapy: clinic and radiologic characteristics and survival outcomes.

INTRODUCTION: Hereditary retinoblastoma survivors have an increased risk for cranio-facial second primary tumours (SPT), especially after treatment with external beam radiotherapy (EBRT). This multicentre study evaluates the clinical and imaging characteristics and outcomes of cranio-facial SPTs in irradiated retinoblastoma survivors. PATIENTS AND METHODS: Clinical and radiological data of 42 hereditary retinoblastoma patients with 44 second and third malignancies were reviewed. Radiological data included anatomic location and computed tomography (CT) and magnetic resonance (MR) characteristics. Cox regression and likelihood ratio chi-square test were used to evaluate differences in patients' survival rates. RESULTS: Cranio-facial SPTs were diagnosed at a median age of 13 years. Histological types included osteosarcomas (43%), rhabdomyosarcomas (20%) (57% embryonal, 43% alveolar) and a variety of other types of SPT (37%). Predilection sites were: temporal fossa (39%), ethmoid sinus (23%), orbit (18%), maxillary sinus (16%) and intracranial dura mater (4%). Most of the osteosarcomas (78%) and rhabdomyosarcomas (80%) occurred in patients treated with EBRT in the first year-of-life. Treatment of SPTs with a microscopically complete surgical resection led to a significantly better 5-year overall survival (OS) (P=0.017) and event-free survival (EFS) (P=0.012) compared to patients treated without surgery or incomplete resection (OS: 83% versus 52%; EFS: 80% versus 47%). CONCLUSIONS: Osteosarcomas and rhabdomyosarcomas are the most common cranio-facial SPTs in irradiated hereditary retinoblastoma survivors, which develop in specific locations and occur predominantly in patients irradiated in their first year-of-life. Microscopically complete surgical resection of SPTs is a major prognostic factor, suggesting the potential benefit of early detection by imaging.

Fibroelastoma dorsi: un tumor infrecuente e infradiagnosticado / Elastofibroma Dorsi: An Uncommon and Under-Diagnosed Tumour

El elastofibroma dorsi es un tumor poco frecuente de los tejidos blandos localizados a nivel infraescapulary/o subescapular. Su incidencia es variable, produciéndose entre la cuarta y la séptima década de la vida,y es más común en las mujeres. Se han revisado 16 casos de elastofibroma diagnosticados en 12 pacientes(7 mujeres, 58,3%), de las cuales 4 pacientes presentaron fibroelastomas bilaterales. El síntoma másfrecuente fue el dolor. El diagnóstico se realizó mediante exploración física, tomografía computarizaday/o resonancia magnética nuclear para confirmar el diagnóstico en casos dudosos. La cirugía de exéresisse realizó bajo anestesia general sin observarse complicaciones mayores. El elastofibroma es un tumorde la pared torácica infrecuente y/o infradiagnosticado con un impacto incierto que requiere su exéresissolo en pacientes sintomáticos(AU)

Elastofibroma dorsi is a relatively rare soft-tissue tumour localized at the infra-scapular level and/orsubscapular regions. It usually occurs between the fourth and seventh decade of life, and is morecommon in females. We reviewed sixteen elastofibromas diagnosed in 12 patients (7 females, 58.3%).Four patients had bilateral elastofibromas. The most common symptom was pain. Presumptive diagnosiswas made by physical examination. Chest ultrasound, computed tomography and/or magnetic resonanceimaging were performed to confirm the diagnosis. Surgery was performed under general anaesthesia.No major complications were observed. Elastofibromas are tumours of the chest wall with an uncertainimpact. Surgical resection is indicated only in symptomatic patients(AU)

Phosphaturic mesenchymal tumor diagnosed by fine-needle aspiration and core biopsy: a case report and review of literature.

Oncogenic (tumor-induced) osteomalacia is a rare paraneoplastic syndrome of phosphate wasting that is frequently associated with phosphaturic mesenchymal tumor (PMT). As the cytologic features of this tumor apparently have not been reported, we describe the fine-needle aspiration (FNA) findings for PMT that arose from the gluteal soft tissue in a patient with hypophosphatemia and multiple fractures secondary to osteomalacia. Smears from the computerized tomography (CT)-guided FNA showed groups of spindle cells having elongated nuclei, fine to moderately coarsely granular chromatin, inconspicuous nucleoli, and delicate cytoplasm. Marked nuclear atypia, mitotic figures, and necrosis were absent. The differential diagnosis included a variety of benign and malignant spindle cell neoplasms such as monophasic synovial sarcoma, leiomyoma, peripheral nerve sheath tumor, fibrosarcoma, and, less likely, metastatic melanoma and sarcomatoid carcinoma. The bland-appearing cytologic features of a spindle cell tumor in a patient with osteomalacia should suggest the diagnosis of PMT.