 The topic for today's presentation is an anterior chest swelling, which was proved to be a biophysic malignant mesothelioma. The author is Dr. Sandar Shraf Khan and co-author is Dr. Zilani Alam from SAGES Medical College and KM Hospital. The aim of this presentation is to determine the approach of chest wall tumors on imaging. Tumors of the chest wall are varied, they can be benign on malignant and they can arise from the rib cage or from the soft tissue. So, in this case, a 50-year-old man presented with a swelling on the anterior chest wall on the right side since one year. He was a grocery shopkeeper by occupation. On examination, the swelling was round, formed non-phloctuant and in mobile. So, a frontal chest radiograph was performed in this patient, which showed a well-defined soft tissue opacity in upper and middle zones of right lung field making an acute angle with lateral chest wall. Lateral wall of the region cannot be demonstrated. There is another soft tissue opacity in the right supra-clavicular region above medial one-third of clavicle. And ultrasound was performed for this region as the swelling was superficial. So, the ultrasonogram shows a well-defined bilobulated homogenous hypoequic mass traversing the intercostal space with a small superficial extrathoracic component and a relatively large intrathoracic component causing compression of the underlying lung parenchymal. The colour Doppler and the spectral Doppler was put and there was minimal internal vascularity seen. And the contrast-enhanced CT scan for this patient was performed, which showed a well-defined, homogeneously-enhancing isodence pleural mass along the anterolateral aspect of the chest wall. There was a loss of the extra pleural fat. There was no evidence of any rib invasion. So, the differential diagnosis in this case could be chest vaultumers which arise from any of the components. So, what are the differentials of any chest vaultumers? So, they can be bone in origin, nerve, soft tissue, vessel or they can be secondary. So, bone tumours which can arise in the chest wall are benign tumours which include osteopondroma and giant cell tumour and malignant which include osteosarcoma, myeloma and condosarcoma. Benign nerve tumours are schwannoma and neurofibroma and malignant nerve tumours are malignant peripheral nerve cell tumour. Then benign soft tissue tumours are lipoma and spindle cell lipoma and malignant soft tissue tumour is liposarcoma and benign vascular tumours are cavernous hemangioma or gromas tumour and malignant are androsarcoma, caposis sarcoma. However, these are the primary tumours. However, the secondary tumours that can be seen in the chest wall are the metastasis, chest wall invasion and by intrathoracic malignancy or lymphoma. So, in our case there is no fat component that is ruling out lipoma or liposarcoma. There is no bony involvement or erosion that is ruling out any bone tumour. There is no characteristic vascular intense enhancement that is ruling out the vascular origin and the nerve tissue tumours would typically show the rib erosion or calcification. She is not seen in this case. So, what we are left is the secondary origin of tumours. For secondary origin we could think of a lymphoma or adenocarcinoma of lung, but the lung appears pretty normal and the tumour appears extra plural. Therefore, there is ruling out these two and there is no history of radiation exposure as well. So, from the radiological differential diagnosis include chest wall invasion by an intrathoracic tumour which could be a lung cancer, plural tumour or a mediasinal tumour or soft tissue metastasis. Then for this the ultrasound-guided biopsy was performed which showed hygrid malignant tumour with spindle and epitheloid cell. An immunolistochemistry study was also done in which the cells expressed AE1, AE3, chaldefinant and WT1. So, these findings were conclusive of malignant biophysic mesothelioma. This is the histopath picture which shows both lineage of cells, that is the epitheloid cells as well as the sarcomatoid cells. These are the epitheloid cells which are closely packed and oval to round in shape. These are the sarcomatoid cells which are widely spread and spindle in shape. This slide is showing the chaldefinant staining which is positive. Plural malignant mesotheliomas arise from the mesothelial cells of Plura, approximately 80% are from Plural origin and the rest could be Peritonian. So, the important risk factor is asbestosis exposure. These tumours can be eryokathic or spontaneous. There could be a germline alteration in BAP-1G. Clinical presentation is usually as dyspnea, chest pain, weight loss or as in RKS, chest wall mass. Deadlessness is due to the Plural effusion. Histologically, there are three cell types which can be seen. One is epitheloid, other is sarcomatoid and other is biophysic. Epitheloid is the most common and is easily treatable. Sarcomatoid is the deadliest type and biophysic is the one in which both the cell lineages are seen as in RKS. The CT features of this mesothelioma is that there is unilaterally Plural effusion, nodular Plural thickening can be seen, interlobe septal thickening or Plural based mass lesion can be seen as in RKS. It can be locally aggressive and the signs of that are seen as the invasion of the chest wall, mediasynom and Plura. So, the chest wall invasion can be seen on CT as obliteration of extra Plural fat planes, invasion of intercostal muscles which is seen in RKS. And there can be displacement of ribs or bone destruction which is fortunately not seen in RKS. So, pulmonary metastasis can also be seen as perilemphantic nodules or masses or lymph nodes. Then MR is superior to CT in evaluation of the local invasion and this activity of the tumor. The tumor is iso or slightly hyper intense on T1, moderately hyper intense on T2 and enhances homogeneously on gagolinium study. This is the T stage. So, I will tell about the T3 stage which is seen in RKS. This locally advanced but potentially resectable tumor. So, at least one of the following should be seen to categorize it as T3. So, involvement of the endothoracic fascia, extension into mediasynom fat, a solitary completely resectable focus of tumor that extends into the soft tissue of the chest wall or a non-transmural involvement of the pericardium. So, this a solitary resectable focus of tumor extending into the soft tissue of chest wall is seen in RKS. Therefore, we classify it as T3. So, there were no lymph nodes or distant meds were seen in RKS. The meds were ruled out by doing a PET CT in this patient and there were no lymph nodes in the thoracic region. So, prognosis is poor in this case with the median survival time of 12 months, several factors reduce the survival time like meds, extensive pleural involvement, etc. The treatment is usually surgery with depending on the stage of the tumor, chemo and radiotherapy can also be given. Thank you.