Slide seminar: Soft tissue and bone pathology Unusual tumors of bone and soft tissue or unusual presentations of common ones Gunhild Mechtersheimer Institute of Pathology, Heidelberg/DE (Sylvia Höller, Basel/CH)
Clinical data 41-year-old female patient Respiratory complaints and retrosternal pain Admission in an external hospital - Diagnosis of a right central tumor with stenosis of the upper main stem bronchus - Worsening of the respiratory situation and total atelectasis of the right lung - Intubation and ventilation Admission from the external hospital, intubated and ventilated - Rigid bronchoscopy for recanalisation of the right main bronchus and for histology acquisition (clinically suspected carcinoid, histologically solid neoplasm without recognizable line of differentiation) - Twelve days later extended right upper lobe resection with bronchus cuff and mediastinal and hilar lymph node dissection.
CT findings
Bronchoscopic findings
Operation specimen Right upper lobe resection with a polypoid, predominately endobronchial mass with eroded surface, measuring 5.1 x 3.2 x 4.3 cm.
Immunophenotype Vimentin EMA EpCam Cytokeratins Neuroendocrine markers Neurogenic markers Melanocytic markers Myogenic markers Vascular markers
Vimentin
EMA
CK5/6
S100
SMA
Ki67 index
Detection of a EWSR1-CREB1 fusion transcript (Archer sarcoma panel) Special finding: 30 bp intronic sequence of CREB1 (camp response elementbinding protein) approximately 6 kb five CREB1 exon 5: The fusion transcript is in frame.
Diagnosis Primary pulmonary myxoid sarcoma with EWSR1-CREB1 fusion
Pulmonary myxoid sarcoma
Pulmonary myxoid sarcoma Only 22 cases reported 13 female and 11 male patients Average age: 46 years; range: 26-80 years Even distribution among right and left lungs Most cases with endobronchial component or in close association with a large bronchus Metastatic disease in 4 patients (18%): brain, kidney, contralateral lung Immunophenotype unspecific: Vimentin +, EMA (+). Molecular findings: 14/19 cases (74 %) EWSR1 split 12/14 cases (86 %) EWSR1-CREB1 fusion transcript
Tumors with EWSR1-CREB1 fusion Primary pulmonary myxoid sarcoma (PPMS) Angiomatoid fibrous histiocytoma (AFH) Endobronchial pulmonary AFH Clear cell sarcoma of soft parts (CCS) Clear cell sarcoma like tumor of the gastrointestinal tract (CCLTGT) Intracranial myxoid mesenchymal tumor (myxoid variant of AFH or novel entity?) Hyalinizing clear cell carcinoma of salivary glands Clear cell odontogenic carcinoma (single description)
Primary pulmonary myxoid sarcoma: Differential diagnoses Salivary gland-like pulmonary tumors Parachordoma/myoepithelioma Chordoid meningioma Low-grade neuroendocrine neoplasm with extensive myxoid change Extraskeletal myxoid chondrosarcoma Poorly differentiated conventional chondrosarcoma Myxofibrosarcoma Myxoid malignant peripheral nerve sheath tumor Myxoid liposarcoma Myxoid leiomyosarcoma Myxoma, aggressive angiomyxoma Epithelioid haemangioendothelioma Inflammatory myofibroblastic tumor
Primary pulmonary myxoid sarcoma: Differential diagnoses Salivary gland-like pulmonary tumors Parachordoma/myoepithelioma Chordoid meningioma Low-grade neuroendocrine neoplasm with extensive myxoid change Extraskeletal myxoid chondrosarcoma Poorly differentiated conventional chondrosarcoma Myxofibrosarcoma Myxoid malignant peripheral nerve sheath tumor Myxoid liposarcoma Myxoid leiomyosarcoma Myxoma, aggressive angiomyxoma Epithelioid haemangioendothelioma Inflammatory myofibroblastic tumor
Conclusion Primary pulmonary myxoid sarcoma Orphan disease Numerous histological mimics Frequent EWSR1-CREB1 fusion Additional molecular findings?
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