Primary intrapulmonary thymoma: A systematic review

Multifocal primary intrapulmonary thymoma successfully resected via robotic-assisted thoracoscopic surgery

Primary intrapulmonary thymoma (PIT) represents a rare subset of ectopic thymoma that arises solely from inside the pulmonary parenchyma. Multifocal PIT, where multiple isolated PIT origins coexist in the lungs, has only been confirmed in one previous case report, in which the patient died before surgical resection. These tumours are difficult to diagnose as imaging findings are non-specific, and non-invasive biopsy often yields inaccurate results. We present the case of a man in his 70s who was referred to thoracic surgery for resection of a presumptive endobronchial pulmonary carcinoid tumour. Only after surgical resection did we identify that the patient had multifocal PIT. In this report, we describe our diagnostic and management process for this patient and review the current literature on PIT.

Primary intrapulmonary thymoma a case report

Primary intrapulmonary thymoma (PIT), defined as the presence of thymoma tissue in the lung without an accompanying mediastinal component, is uncommon and so offers a diagnostic quandary. We describe the case of PIT in an 81-year-old man.

Primary Intrapulmonary Thymoma Appearing as a Solitary Pulmonary Nodule: The "Master of Disguise" of Lung Tumors?: Case Report

Primary intrapulmonary thymomas (PITs) are defined as thymomas arising in intrapulmonary locations, without an associated mediastinal component. They are rare lesions, the diagnosis of which can be very difficult. We present a case of PIT in an asymptomatic 74-year-old woman in whom pulmonary nodules were found on pulmonary angiography performed for an episode of pulmonary embolism. She underwent wedge resection and the pathology report revealed a PIT. We also summarize this patient’s clinicopathological features and discuss the diagnosis, pathogenesis, and treatment of PIT.

Multifocal Primary Intrapulmonary Thymoma: A rare subtype of ectopic thymoma

Primary Intrapulmonary Thymoma (PIT) is an infrequent ectopic lung tumor that poses a diagnostic dilemma and has a poorly understood origin. We report a previously healthy 61-year-old lady who presented with cough and weight loss for a month. Diagnostic imaging showed a large left upper lobe mass and two multifocal pleural based nodules in the left lower lobe. She underwent Computed Tomography (CT) guided biopsy of the lung mass and histopathological findings was consistent with a combined Type B1 and B2 thymoma. She was planned for 6 cycles of neoadjuvant chemotherapy with the intent of achieving tumor downstaging and resectability. Due to the lack of established evidence for management of unresectable disease, we wish to highlight the importance of multidisciplinary consensus before pursuing multimodality treatment.

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.

Primary Intrapulmonary Thymoma Presenting as a Solitary Pulmonary Nodule

Primary intrapulmonary thymoma (PIT) is a very rare lesion of uncertain pathogenesis. PIT should be considered when the histopathological appearance of a lung tumor shows features that are uncommon but similar to those of a thymoma. In this case report, we discuss the case of a 59-year-old female with a solitary pulmonary nodule that was confirmed to be PIT on the basis of pathological tests. Treatment with complete resection showed good results.

The spectrum of ectopic thymomas

Thymomas are rare tumors that usually manifest in the anterosuperior mediastinum. Occasionally, thymomas may also originate from ectopically dispersed thymic tissue and can arise in locations such as the neck, lung, or pleura or other locations in the thoracic cavity. The occurrence of thymomas in these ectopic locations can cause substantial diagnostic difficulty as the entity is almost never included in the differential diagnosis and its biphasic morphology can cause further complications during the diagnostic process. In this review, we summarize the clinical and pathological spectrum of ectopic thymomas and discuss the histogenesis, treatment, and prognosis of these extraordinary tumors.

Bilateral multiple intrapulmonary nodules: a puzzled and rare disease

Primary intrapulmonary spindle cell thymomas (PISCT) are rare lesions that may be mistaken for a variety of benign and malignant epithelial or mesenchymal tumors. It is thought as one subtype of primary intrapulmonary thymomas (PIT). To the best of our knowledge, no bilateral multiple primary intrapulmonary spindle thymomas and treatment had been reported in literature. We fortunately diagnosed and managed this unique case, which might provide some experience for physicians who were interested in this disease.

Differential diagnosis of primary intrapulmonary thymoma: a report of two cases

Primary intrapulmonary thymomas (PITs), which are intrapulmonary tumors without an associated mediastinal component, are very rare. The diagnosis of a PIT can be difficult. Here, we report two cases of resected PITs that were difficult to differentiate from other lung tumors. The patients, of a 62-year-old man and a 64-year-old woman, had no significant symptoms and were both referred to our hospital due to the presence of an abnormal shadow on chest computed tomography (CT). The patients underwent ¹⁸F-fluorodeoxyglucose positron emission tomography-CT (FDG-PET/CT) and subsequently tumor excision. A PIT was confirmed histopathologically in the surgical specimens from both patients. In one case, the tumor consisted of a type A thymoma without abnormal FDG uptake. In the other case, the tumor consisted of a type B2 thymoma presenting with weak FDG uptake. This report thus documents two cases of PITs with different histopathologic and FDG-PET/CT findings. Thoracoscopic surgery is essential in the differential diagnosis between PITs and other lung tumors.

Undifferentiated pleiomorphic sarcoma simultaneously occuring with thymoma

We report here a case of thymoma simultaneously associated with neuroendocrine tumor. A 65-year-old male, presented with cough. Radiographic studies showed a mediastinal mass. On fine needle aspiration cytology and histopathological examination, a diagnosis of thymoma with coexisting undifferentiated pleomorphic sarcoma was made. Although thymoma is associated with many extrathymic malignancies, its association with neuroendocrine tumor is rare. This case is being reported on to reinforce that clinicians should bear in mind the possibility of extrathymic malignancies in patients with thymoma.

Primary intrapulmonary thymoma

Primary intrapulmonary thymoma (PIT), which is an intrapulmonary tumor without an associated mediastinal component, is rare. We herein report a resected case of PIT in a 55-year-old female who presented with a 2.5 × 2.4 cm mass in the left upper lobe. We also summarize the clinicopathological features and discuss the diagnosis, pathogenesis, and treatment of PIT.

A rare case of ectopic laterocervical thymoma

The ectopic cervical thymoma is a rare site for a thymus neoplasm. It is frequently confused with cyst or with later neck mass of uncertain diagnosis until a histological diagnosis is made. Thymic neoplasms normally arise in the mediastinum, causing signs and symptoms of compression of the adjacent structures. Although rare, malignant thymomas may develop from an ectopic thymus, situated in the thyroid gland (Miyauchi et al., 1985; Matsuura et al., 2004), the neck (Yan et al., 2010; Yao et al., 2010; Jung et al., 1999), the lungs (Myers et al., 2007), and the heart (Miller et al., 2005). It is thought to be caused by the persistence of embryological organ portions along its route of physiological descent from the neck into the mediastinum during embryological development. The incidence of ectopic thymoma is around 4%. The thymus is a lympho-epithelial organ that is the centre of the development and maturation of the T lymphocytes. It develops from the ventral portion of the third and fourth pharyngeal pouches and by the sixth week of gestation it descends into the anterior mediastinum. It has a lobular structure with an external or cortical portion, richly populated by immature T cells, thymocyte and an internal medullary part.

Respiratory Tract and Mediastinum

Normal cytology, abnormal and atypical cells, non-cellular components, and infectious cell changes are largely described together with benign, malignant, and neuroendocrine lesions regarding exfoliative and aspiration cytology of the lung. A separate section broadly addresses diagnostic findings and differential diagnoses in bronchoalveolar washings.

The section ‘Fine needle aspiration biopsy of mediastinal disorders’ covers in particular biopsy techniques, accuracy of liquid-based cytology, and the complex lesions of the thymus gland. Cytodiagnostic algorithms of the major benign and malignant pulmonary and mediastinal lesions and their respective differential diagnoses are additionally presented in synoptic setups.

Thymoma with coexisting undifferentiated pleomorphic sarcoma: a case report

We report here a case of thymoma simultaneously associated with undifferentiated pleomorphic sarcoma. A 45-year-old male presented with axillary lump. Radiographic studies showed a mediastinal mass. On fine needle aspiration cytology and histopathological examination, a diagnosis of thymoma with coexisting undifferentiated pleomorphic sarcoma was made. Although thymomas are associated with many extrathymic malignancies, it's association with undifferentiated pleomorphic sarcoma is rare. This case is being reported on to reinforce that clinicians should bear in mind the possibility of extrathymic malignancies in patients with thymomas.

Ectopic cervical thymoma: a report of two cases of a rare entity frequently misdiagnosed on fine needle aspiration cytology and frozen section

Ectopic cervical thymoma (ECT) is a rare tumor that is frequently misdiagnosed on fine needle aspiration cytology and frozen section. Using conventional light microscopy and immunohistochemistry, we characterized the only two cases of ECT found in our institutional files over a period of 20 years. Both tumors were classified as type AB-thymoma. Neoplastic cells expressed cytokeratins but not CD5. Non-neoplastic T-lymphocytes were positive for CD3 and CD5. Lymphocytes expressed CD1a in only one case. One tumor breached the capsule and had positive surgical margins. For this patient, adjuvant radiotherapy was given. The other patient has had an uneventful follow-up for 20 years with no other therapy than surgery. Both cases of ECT showed identical histomorphological and immunohistochemical features of type AB-thymomas originating in the thymus. Short follow-up precludes conclusion on the implication of positive margins in conjunction with adjuvant radiotherapy for one of the patients presented herein.

Association between thymoma and persistent hypothermia: a case report

INTRODUCTION

Thymomas are rare, slow-growing tumours that present in a variety of ways such as incidental findings on chest radiographs following symptoms of cough and dyspnoea. Thymomas may also present with symptoms due to intrathoracic spread such as superior vena cava obstruction, or with symptoms of an associated paraneoplastic disorder. Such paraneoplastic disorders are typified by the generation of autoantibodies directed against a variety of self antigens including myasthenia gravis, neuromyotonia, and hypogammaglobulinaemia. Significant hypothermia in association with thymoma has been described previously in one published case report. The basis for hypothermia in that case was not clear, but was postulated to relate to abnormal central thermal regulation and was resolved completely following treatment with intravenous gammablobulin, thus suggesting an autoimmune aetiology.

CASE PRESENTATION

We present the case of an 88-year-old man with Type A thymoma and persistent hypothermia. An extensive investigation of the hypothermia revealed no aetiology other than the thymoma itself. Symptoms of hypothermia were treated effectively with passive and active external rewarming. The patient's dyspnoea was much improved by intercostal drainage of a left-sided pleural effusion and talc pleurodesis. He was not offered definitive treatment for the thymoma in view of its relatively favourable prognosis, and because his symptoms were well controlled at the time of discharge.

CONCLUSION

We suggest that the possibility of thymoma be investigated once the more common causes of hypothermia have been excluded in an appropriate clinical context. To the best of our knowledge, this is only the second published case report describing such an association.

Primary Intrapulmonary Thymomas: Case Report and Review of the Literature

Primary intrapulmonary thymomas (PIT), which are intrapulmonary tumours without an associated mediastinal component, are very rare; only 29 cases of PIT have been described in the literature since 1951. This report presents a case of PIT in a 59-year old Chinese woman with a type A thymoma (including its pathogenesis, clinical pathological characteristics, immunological phenotype, treatment and prognosis), in the context of a review of the current literature. The origin of thymomas in this unusual location remains unknown. In this case, immunohistochemical analysis demonstrated that the epithelial component was strongly positive for cytokeratin and focally reactive for epithelial membrane antigen. It is concluded that PIT should be considered when the histopathological appearance of a lung tumour is not typical of other pulmonary neoplasms. Complete resection appears sufficient in non-malignant tumours, while in cases of partial resection or malignancy, adjuvant radiotherapy should be considered. Long-term regular clinical follow-up is also warranted, due to the risk of late local recurrence.