Ectopic thymoma in the paratracheal region of the middle mediastinum: a rare case report and literature review

[Epithelioid Hemangioendothelioma Presenting as a Right Paratracheal Mass: A Case Report]

Epithelioid hemangioendothelioma (EHE) is a low-grade malignant vascular neoplasm that can occur anywhere in the body. EHE has a low annual incidence (0.38/106) and prevalence (< 1/106), and primary mediastinal EHE is exceedingly rare. We report a case of EHE in a 53-year-old female which manifested as an incidentally discovered mass in the right paratracheal region. In this report, authors describe the pathological and radiological findings of primary mediastinal EHE invading the superior vena cava in the right paratracheal area.

An ectopic thymoma arising in the middle mediastinum that was difficult to distinguish from a lymph node metastasis

BACKGROUND

Ectopic thymomas often occur in the upper mediastinum; however, they rarely arise in the middle mediastinum, especially on the dorsal side of the innominate vein and superior vena cava in the peribronchial region.

CASE PRESENTATION

Six years prior, a 27-year-old female presented to our department and was diagnosed with locally advanced left breast cancer. First, we administered chemotherapy including an anti-human epidermal growth factor receptor 2 antibody. The size of the tumor was markedly reduced, and a radical operation involving mastectomy and axillary lymph node dissection was then performed. The patient underwent radiotherapy after the mastectomy, followed by trastuzumab therapy; she continued to receive endocrine therapy thereafter. She underwent computed tomography once a year after the surgery, and a nodule in the middle mediastinum on the dorsal side of the innominate vein and superior vena cava in the parabronchial region was detected at 4 years. We speculated that the nodule was a solitary mediastinal lymph node metastasis from her breast cancer; therefore, we performed thoracoscopic resection of the tumor. We diagnosed the tumor as a thymoma. Currently, the patient visits our hospital to receive continuous hormone therapy for her breast cancer, and the latest computed tomography scan demonstrated no metastases from or recurrence of her breast cancer or thymoma.

CONCLUSIONS

We report a case of ectopic thymoma in the middle mediastinum. The tumor, which was detected during systemic therapy for locally advanced breast cancer, was located on the dorsal side of the innominate vein and superior vena cava in the parabronchial region and was indistinguishable from a lymph node metastasis from breast cancer.

How to obtain adequate biopsy specımen in suspected thymic tumors

Pathologic diagnosis of thymic tumors (TTs) can be made by surgical or nonsurgical procedures. About 20% of TTs had been diagnosed by pretreatment biopsy methods while the rest had gone to surgery for diagnosis and treatment. However, in the last two decades there was an increase in pretreatment procedures for optimal management of locally advanced or metastatic TTs. Pretreatment tissue diagnosis of a noninvasive TT is not a standard option but is required if there is suspect or atypical clinical presentation and imaging, an invasive tumor requiring a nonsurgical approach or preoperative chemotherapy or chemo-radiotherapy, strong possibility of lymphoma or unclear differential diagnosis between lymphoma or other solid tumor by imaging studies, or suspicion of a metastatic lesion. In surgical diagnosis anterior mediastinotomy, video-assisted thoracic surgery or mediastinoscopy can be chosen for invasive TTs whereas total resection is performed for small, noninvasive tumors. Nonsurgical diagnosis can be made by transthoracic fine or core needle biopsies (TTFNA, TTCNB), conventional bronchoscopy, endobronchial ultrasonography-guided transbronchial needle aspiration (EBUS-TBNA), endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) or medical thoracoscopy depending on procedural amenability according to tumor extension. TTFNA and TTCNB have been the most frequently used nonsurgical methods. However, there is an upward trend in using conventional bronchoscopy, EBUS-TBNA, EUS-FNA and medical thoracoscopy recently. To increase the diagnostic performance of these procedures in TTs, recommendations are (I) obtaining histologic specimens, (II) combining smears or liquid based cytology preparations and cell blocks, (III) obtaining multiple sufficient samples, (IV) combining histologic and cytologic specimens, (V) performing morphologic, immunohistochemical and molecular analyses on all specimens, (VI) using rapid onsite evaluation for cytologic specimens, (VII) correlating pathologic, clinical and radiologic findings, (VIII) consulting experienced pathologists.

Bloody Pericardial Effusion with a Huge Pericardial Mass: A Case Report

Nowadays, the early diagnosis of tumoral diseases is more possible and accurate with multiple diagnostic imaging modalities such as chest X-ray, echocardiography, computed tomography, and magnetic resonance imaging, especially for cardiac tumors which are usually asymptomatic, even in large sizes. In cardiac masses, the patients' presentations are non- specific and dependent on the tumor size and site as well as its compressive effect on the adjacent structures. On the other hand, the first and last signs could be sudden cardiac death. However, cardiac masses are either benign or malignant and metastatic in their malignant type, and their definite diagnosis is only possible by surgical tumor resection and tissue biopsy. In this paper, we describe an old patient with severe pericardial effusion and an unusual intrapericardial tumor in transthoracic echocardiography, representing a rare case of a giant ectopic thymoma after surgical resection and pathologic assessment.

Ectopic thymoma: Retrospective analysis of eight cases with clinical features and computed tomography findings

OBJECTIVE

To analyze the computed tomography (CT) and clinical features of ectopic thymoma, and to be familiar with the CT diagnosis of this disease.

MATERIALS AND METHODS

CT data, clinical data, and pathological data of eight cases of ectopic thymoma, confirmed by pathology from September 2013 to June 2019, were retrospectively analyzed.

RESULTS

Eight cases of thymoma were diagnosed, which included three in mediastinum (one of B1 type, two of C type), two in pericardium (both of B3 type), one in lung (B1 type), one in pleura (AB type), and one in right atrium (B2 type). Among the eight cases, four were men and four were women, aged 36-70 years. The clinical manifestations were chest tightness, shortness of breath and cough, and one case of myasthenia gravis. Six of the 8 patients were misdiagnosed as lymphoma, solitary fibrous tumor, malignant teratoma by CT. CT showed the following: the long diameter of tumor was 4.2 cm-19.5 cm, the shape was elliptical or round, and one case of ectopic thymoma grew in the atrium. The density was homogeneous in two cases and heterogeneous in six cases. The boundary was clear in three cases and unclear in five cases. Among the eight cases, three showed pleural effusion, two showed pericardial effusion and three showed calcification.

CONCLUSIONS

Ectopic thymoma is rare and often misdiagnosed due to abnormal position. However, CT findings of ectopic thymoma are similar to those of the anterior superior mediastinal thymoma.

Ectopic thymoma: report of 2 cases and review of the literature

In this report, we present two cases of ectopic thymoma, aiming to explore the clinicopathologic features, diagnosis, and differential diagnosis of ectopic thymoma. Case 1 was a female 56-years-old. For 6 months' time, there was no obvious cause of cough, expectoration, chest tightness, or asthma with chest pain. PET-CT showed a right middle lung and lower lung mass with increased FDG metabolism. Postoperative pathology was diagnosed as right middle and lower lung ectopic thymoma, type B2, invading the chest wall. Case 2 was a male of 54-years-old. By physical examination the right chest cavity had a mass present for 1 week and he was admitted to hospital. Postoperative pathology was diagnosed as right thoracic ectopic thymoma, type AB. No recurrence has been found to in the follow-up of these two patients. In conclusion, ectopic thymoma occurs outside the anterior mediastinum. It is rare, the clinical symptoms are not typical, and pre-operative diagnosis is difficult. It is easily misdiagnosed as other diseases. Surgical treatment is the best method. According to the pathologic type and invasion of the tumor, radiotherapy may be considered.

[Ectopic thymic tissue and ectopic thymic tumors]

Ectopic thymic tissue outside its core position in the antero-superior mediastinum is quite common owing to the complexity of embryonal thymus development, whereby reported prevalence values (1 to 90%) are heavily dependent on the method of investigation and the intensity of the workup. The debated prevalence and relevance of ectopic thymic tissue and its accessibility underlie the ongoing discussion whether modern, minimally invasive thymectomy strategies can match the proven benefit of the radical transsternal thymectomy procedure for the treatment of Myasthenia gravis. In this context, the following article covers the etiology, prevalence, and location of normal-looking, reactive, and neoplastic ectopic thymic tissue. Furthermore, ectopic tissues and tumors inside or adjacent to the thymus are mentioned.