CASE REPORT OF UNUSUAL PRESENTATION OF INVASIVE THYMOMA IN A 49 - PDF document

DOI: 10.5958/2319-5886.2016.00021.7 Available online at: www.ijmrhs.com Case report Open Access CASE REPORT OF UNUSUAL PRESENTATION OF INVASIVE THYMOMA IN A 49 YEARS OLD MALE Dr.Osama Abdalla Mabrouk Kheiralla ARTICLE INFO ABSTRACT Received: 27 th Aug 2015 Invasive thymomas are rare tumours in the anterior mediastinum, Revised: 4 th Nov 2015 representing 50% of anterior mediastinal masses and about 20-30% of all Accepted: 14 th Nov 2015 mediastinal tumours. They are of unknown etiology; about 50% of patients with thymomas are diagnosed incidentally with chest radiography. Thymoma Author details: Assistant Professor of is classified into different stages, which determine the prognosis and type of Radiology, Department of Radiology, management, the standard primary treatment for these tumours is Faculty of Medicine - University of Thymectomy. This case study presents a 49 year-old man with unusual Najran presentation of thymoma. On the non-contrast CT images, there was a well- defined heterogeneous anterior mediastinal mass adjacent to the right border Corresponding author: Osama of the heart. There was evidence of infiltrations into the anterior mediastinal Assistant Professor of Radiology, fat but no mediastinal lymphadenopathy after contrast enhancement, the Department of Radiology, Faculty of Medicine - University of Najran mass showed heterogeneous enhancement. CT guided trucut tissue biopsy Email: drkheiralla@gmail.com and histological analysis of the mass showed that the tumour consists of neoplastic epithelial cells and non-neoplastic lymphocytes. The findings were Keywords: Mediastinal tumours, consistent with invasive lymphoepithelial thymoma. Anterior mediastinal masses, Tumours of the Thymus, Invasive thymomas INTRODUCTION Thymus is an anterior mediastinal lymphoid organ that is heterogeneity of cells within thymomas is a major factor mainly composed of epithelial cells in the outer cortex, guiding this intense debate [11, 12]. myoid cells and lymphocytes in the germinal centre. Currently, computed tomography is the first choice Thymus originates in the embryo from the ventral ring of technique to characterize a mediastinal mass with regard 3rd and 4th pharyngeal pouches and ectoderm endoderm to its anatomic dissemination and invasion of neighboring of the cervical sinus, as epithelial outgrowths on each structures, as well as possible distant metastases [5]. side [1, 2, 3]. The thymus is responsible for the Applying computed tomography, thymomas can often be processing and maturation of T-lymphocytes. Being distinguished from benign mediastinal lesions or from located in the upper anterior mediastinum and lower part lymphoma in the case of multiple mediastinal of the neck, the thymus is active during childhood and abnormalities [13]. Magnetic resonance imaging is involutes after puberty being replaced by adipose tissue frequently implemented in the radiologic diagnosis of gradually thereafter, although it never disappears thymomas [14]. The major role of the magnetic completely [4]. After birth, the thymus starts to grow to resonance image seems to lie in its value for surgical reach its maximum weight of 40 grams around puberty, planning, especially if resection of thymomas is and then it involutes and persists in an atrophic state into considered that invade neighboring structures such as old age. the great vessels or the heart [5]. Thymomas are rare neoplasms arising from tissue As the only curative treatment, surgery remains the elements of the thymus and developing in the anterior baseline attempt in thymoma therapy. Complete or partial mediastinum [5, 6]. They can be associated with a variety median sternotomy with complete thymectomy is the of systemic and autoimmune disorders, such as pure red operative approach of choice [15-19]. cell aplasia, pancytopenia, hypogammaglobulinemia, collagen-vascular disease, and most commonly with CASE REPORT myasthenia gravis [5, 7, and 8]. Thymomas are uncommon tumors with an annual incidence of only 0.15 A 49-year-old man was referred to our department cases per 100,000 person-years [5, 9], yet representing complaining of chronic cough. Chest x-ray was done revealed a well-defined lobulated right liar mass (Fig.1) . the most frequently diagnosed tumor of the anterior mediastinum [5, 10]. Contrast enhanced Computerized tomography was Several classification systems of thymomas have been performed with a 64-detector scanner. On the non- developed and described. However, clinical, pathologic, contrast CT images, there was a well-defined and surgical classification of thymomas remains heterogeneous anterior mediastinal mass adjacent to the controversial. The histomorphologic variability and right border of the heart. There was no definite invasion 101 Osama Int J Med Res Health Sci. 2016;5(1):101-104

to superior vena cava or right brachiocep cephalic vein. There neoplastic epithelial cells ells and non-neoplastic was evidence of infiltrations into the an anterior mediastinal lymphocytes. The findings we were consistent with invasive fat but no mediastinal lymphadenopat pathy (Fig.2). After lymphoepithelial thymoma. Th The patient was referred to contrast enhancement, the mass showe wed heterogeneous the oncology centre for further er management. enhancement (Fig.3). DISCUSSION Tumours of the thymus are re among the rarest human neoplasms, comprising <1% o of all adult cancers, with an incidence rate of 1–5 / m million population / year. Thymomas are the most fre frequent thymic tumours in adults, followed by mediasti stinal lymphomas, some of which arise from mediastinal al lymph nodes. In children, the mediastinum is the site o of 1% of all tumours; most common are non-Hodgkin lym lymphomas, while thymomas are extremely rare [20]. Thymomas and thymic car carcinomas are uncommon tumours with an annual incid cidence of approximately 1-5 Fig 1: AP chest x-ray showing g a well-defined per million population [21]. 1]. Thymoma is the most lobulated right hilar mass of soft oft tissue density common neoplasms arising g in the thymus originating obscuring the right upper border o of the heart and from epithelial cells of thymus, us, it accounts for about 25% great vessels, no pleural effusion. of all mediastinal tumours with ith a peak incidence between 40 and 50 years of age. Patients with thymoma are of often clinically asymptomatic [22]. However, it may pres resent with local symptoms related to encroachment on on adjacent structures, as cough, chest pain or superior ior vena cava syndrome. The symptomatic patients may h have only local symptoms related to the presence o of the tumor within the mediastinum or only sympt ptoms related to systemic disease states that are frequ quently associated with the presence of thymoma or a co combination of both [22]. In case of disseminated dise isease, the most common manifestations are pleural or p r pericardial effusions, which may be associated with thorac acic symptoms. Fig 2: Axial Non contrast CT scan d n demonstrating a Thymoma may be associate ated with different types of well-defined soft tissue mass measu asuring about 6X4 paraneoplastic disorders witho thout clear etiological factors, cm abutting the right boarder of th the heart and the the most common of which is m is myasthenia gravis, which is superior vena cava, no lymph nodes. s. seen in 30 to 40 % thymoma c a cases. Myasthenia gravis is an autoimmune disease affe affecting the neuromuscular junction of voluntary muscle le due to interference with acetylcholine receptors. Myas asthenia gravis (MG) is the most common PTS encounte ntered [22, 23, 24, 25]. This syndrome (MG) is present in a n approximately 30 to 59% of patients with thymoma [24, 25] 25]. Radiographically thymoma app ppears as a soft tissue mass with ill-defined borders and d infiltrative growth into the surrounding structures, medias iastinal fat planes and pleural surfaces. It may invade the t e trachea, pericardium, heart and great vessels. Generally i ly it may not appear on chest x-ray, contrast enhanced CT T is useful in delineating the Fig 3: After contrast, the mass showed mass and in defining its v vascularity and extent of invasion. Definite diagnosis of of thymoma is confirmed by heterogeneous enhancement tissue CT guided trucut biopsy psy or fine-needle aspiration. A fine-needle aspiration (FNA) A) biopsy is an accepted and Abdominal ultrasound was done an and no significant feasible method to differentiate ate mediastinal lesions and to abnormality was detected. Rou outine laboratory diagnose or classify thymom mas histopathologically [26, investigations were done for him, which ich revealed a white 27]. blood cell count of 11 × 109/L, , with lymphocyte The differential diagnosis for an invasive anterior f predominance of 50%; haemoglobin n level of 15 g/dl; mediastinal mass includes i invasive thymoma, thymic Haematocrit is 52%; and platelet count unt of 260 × 109/L. carcinoma, lymphoma, metas tastasis, malignant germ cell CT guided trucut tissue biopsy and his histological analysis tumours and primary sarcom omatous tumors. They show of the mass showed that the tum umour consists of 102 102 102 Osama Int J Med Res Health th Sci. 2016;5(1):101-104