Basaloid carcinoma of the thymus

A basaloid carcinoma with multilocular thymic cyst mimicking a mediastinal teratoma

This case report details a rare thymic basaloid carcinoma initially misinterpreted as a mediastinal teratoma, underscoring the diagnostic challenges posed by such tumors. A 71-year-old female presented with an asymptomatic anterior mediastinal tumor discovered incidentally during a routine health examination. Surgical intervention, followed by pathological and immunohistochemical analysis including CK-pan, p63, p40, and CD117 molecules, led to a definitive diagnosis of basaloid carcinoma of the thymus. This case highlights the critical importance of differential diagnosis in mediastinal lesions, especially those presenting with multilocular thymic cysts on chest CT. The subxiphoid video-assisted thoracoscopic surgery enabled complete tumor resection with minimal trauma and favorable postoperative outcomes. The patient opted against further radiotherapy or chemotherapy and she has survived for over eight months without recurrence. This case report contributes to the growing understanding of thymic basaloid carcinoma, a rare and potentially aggressive thymic carcinoma subtype. It emphasizes the necessity for precise surgical techniques and enhanced diagnostic acumen among cardiothoracic surgeons and oncologists.

Basaloid Squamous Cell Carcinomas of the Thymus With Prominent B-Cell Lymphoid Hyperplasia: A Clinicopathologic and Immunohistochemical Study of 10 Cases

Ten cases of basaloid squamous cell carcinomas of the thymus are presented. The patients are 6 women and 4 men ranging in ages between 51 and 72 years (average: 61.5 y), who presented with nonspecific symptoms of cough, dyspnea, and chest pain with no history of malignancy, myasthenia gravis, or other autoimmune disease. Surgical resection of the mediastinal masses via thoracotomy or sternotomy was performed in all patients. Grossly, the tumors varied in size from 2 to 8 cm, were light tan in color, solid and slightly hemorrhagic, and had infiltrative borders. Histologically, scanning magnification showed elongated interanastomosing ribbons of tumors cells embedded in a lymphoid stroma containing germinal centers. At higher magnification, the tumors cells were round to oval with moderate amounts of lightly eosinophilic cytoplasm, oval nuclei, moderate cellular atypia, and mitotic activity ranging from 3 to 5 mitotic figures per 10 HPFs. In 8 cases, the tumor invaded perithymic adipose tissue, in 1 case the tumor infiltrated pericardium, and in 1 case, the tumor involved the pleura. Immunohistochemical stains showed positive staining in the epithelial component for pancytokeratin, p63, keratin 5/6, and p40, while CD20 and CD79a characterized the lymphoid component. Clinical follow-up was obtained in 7 patients. Two patients died within 24 months and 5 patients remained alive between 12 and 60 months. The current cases highlight the unusual feature of B-cell lymphoid hyperplasia in these tumors and their potential aggressive behavior.

Thymic basaloid carcinoma with aggressive invasion of the lung and pericardium: report of a case

We report a case of basaloid carcinoma of the thymus, invading the lung and pericardium. The patient was a 72-year-old man who suffered thoracic trauma in a fall and was taken to his family physician. Computed tomography revealed a huge mediastinal tumor with cystic components, pressing into the lung. He was referred to our hospital, where magnetic resonance imaging showed suspicious invasion of the pericardium and mediastinum. We made an assumed diagnosis of a mediastinal malignancy and performed mediastinal tumor resection. The tumor was adherent to the lung, pericardium, and left innominate vein. The final pathological diagnosis was a basaloid carcinoma of the thymus. Basaloid carcinoma is often a component of a multiloculated thymic cyst (MTC) and should be considered when MTC is identified within an anterior mediastinal tumor.

Analysis on the clinical features of 22 basaloid squamous cell carcinoma of the lung

BACKGROUND

Basaloid squamous cell carcinoma of the lung is a rare and highly malignant tumor mostly observed in the proximal bronchi. Basaloid squamous cell carcinoma of the lung cases typically show rapid clinical progression, very poor prognosis and special pathological morphology. This project aimed to examine the clinical features of basaloid squamous cell carcinoma of the lung and the factors related to its prognosis; and to compare survival outcomes between basaloid squamous cell carcinoma and poorly differentiated squamous cell carcinomas (PDSC).

METHODS

Between January 2004 and December 2008, pathological sections from basaloid squamous cell carcinoma and PDSC of the lung were collected and retrospectively analyzed at Tianjin Medical University Cancer Institute and Hospital. Data analysis was performed using Statistical Package for the Social Sciences (SPSS11.0). The Kaplan-Meier method was used to calculate the survival rate. Log-rank test was used to compare the differences in survival rate between the two groups. The factors influencing prognosis were analyzed using the Cox proportional hazard model.

RESULTS

A total of 120 pathological sections were used in the analysis of this study-22 from basaloid squamous cell carcinoma cases and 98 from PDSC cases. Compared to the PDSC group, the basaloid squamous cell carcinoma group had a larger proportion of female patients (p = 0.001); however it had higher proportion of male smokers (p = 0.003). There were no statistically significant differences in survival rate between the two groups (χ2 = 1.200, p = 0.273). Additionally, prognosis of basaloid squamous cell carcinoma is significantly influenced by treatment mode and clinical stages of the tumor. The post-operation mortality hazard of patients treated with a combination chemotherapy and radiotherapy was 1.296 times higher than other treatment modes (p = 0.025). Increases in post-operation mortality hazard ratio were also associated with more advanced clinical stage of tumors (χ2 trend = 11.907, p = 0.000).

CONCLUSIONS

This study demonstrated that basaloid squamous cell carcinoma and PDSC have very similar clinical features, and there are no significant differences in survival rates between the two groups. Hence, we conclude that in the short term, the same clinical treatments and therapeutic modes can be administered to patients with basaloid squamous cell carcinoma and PDSC of the lung.

Thymic basaloid carcinoma with pleural dissemination that developed after a curative resection: report of a case

Thymic basaloid carcinoma is an extremely rare tumor type, with only 10 such reports published to date in the English literature. We herein present a new case of thymic basaloid carcinoma with pleural dissemination that developed after a curative resection. A cystic tumor in the anterior mediastinum was observed in a 72-year-old man, and the tumor was completely resected via a median sternotomy with a combined resection of the adjacent structures. One year later, pleural disseminated nodules developed in the right thorax, which were resected through a right thoracotomy. The present case and the review of previous cases indicated that this rare tumor, which had previously been considered to be a low-grade malignant thymic carcinoma, may therefore have a more obstinate and aggressive malignant nature. Histopathologically, a few CD5-positive tumor cells were observed in isolation in the squamous epithelium of the inner cyst wall, thus suggesting that malignant transformation subsequently occurs in a preexisting cyst.

Thymic basaloid carcinoma: a clinicopathologic study of 12 cases, with a general discussion of basaloid carcinoma and its relationship with adenoid cystic carcinoma

Thymic carcinoma (primary carcinoma of the thymic epithelium; type C thymoma) is a rare malignancy. It usually presents in middle-aged to elderly patients and can exhibit a wide variety of morphologic appearances. Thymic basaloid carcinoma (thymic BC) is a particularly rare subtype, with less than 20 cases published in the English literature, mostly in the form of individual case reports. In this study, we present the clinicopathologic and immunohistochemical features of 12 new cases of thymic BC. There were 10 (83%) men and 2 (17%) women. Ages at the time of initial diagnosis ranged from 34 to 77 years (mean 55 y). The 2 most common manners of presentation were dyspnea on exertion (3 patients) and as an incidental finding on radiographic imaging (2 patients). Tumors ranged in size from 4.4 to 17 cm (mean 10.1 cm). One of 12 cases (8.3%) was associated with a multilocular thymic cyst. Immunohistochemistry was performed in 8 cases. Pan-cytokeratin was positive in all cases. CD117 (c-kit) was positive in 6 of 8 cases (75%), p63 was positive in 7 of 8 cases (88%), p53 was positive in 7 of 8 cases (88%), ranging from <10% to 90%, CD5 was focally positive in 3 of 8 cases (38%), collagen type IV was positive in 4 of 8 cases (50%), and proliferative index, as estimated by Ki67, ranged from <1% to approximately 15%. In 1 of 2 cases with sarcomatoid differentiation, Ki67 was greater than 80% in the sarcomatoid area. Cases were negative for thyroid transcription factor-1 (0 of 8), S-100 (0 of 7), and synaptophysin (0 of 7). Long-term data was available in 8 patients with an average follow-up of 30 months. Five patients died of their disease at an average of 34 months from the time of diagnosis. Of the remaining 3 patients, 1 had a stable recurrence and died at 4 years from unrelated causes, and 2 were alive without the evidence of disease at 12 and 7 months, respectively. Thymic BC, although previously regarded as a low-grade neoplasm, has shown that it is capable of aggressive behavior and significant mortality. In this paper, we review the pertinent literature and discuss the possible relationship of thymic BC with thymic adenoid cystic carcinoma, as well as BCs and adenoid cystic carcinomas at other sites.

Thymic carcinoma: update of current diagnostic criteria and histologic types

Thymic carcinomas are rare tumors thought to derive from thymic epithelium. Because of the complex embryological origin of the thymus, whose development includes contributions from the third and, to a lesser extent, the fourth pharyngeal pouches, thymic carcinomas are endowed with great morphologic heterogeneity. A large number of histologic types have been described that resemble tumors arising in other organs. Unfortunately, no definitive pathognomonic histological features or immunohistochemical markers are associated with these tumors, making them a real challenge for diagnosis. Because of their close similarity with tumors arising at other organs, the diagnosis of thymic carcinoma must be regarded, for the most part, as a diagnosis of exclusion. This review will focus on current criteria for diagnosis of these tumors, with a review of the various histopathologic appearances that they can adopt.

Cystic lesions of the mediastinum

Cysts of the mediastinum comprise a relatively diverse group of lesions that include neoplastic and nonneoplastic constituents, the latter of which are largely congenital in nature. Therefore, a grasp of their clinicopathologic characteristics is bolstered by knowledge of which tumors in the chest may undergo cystic change, as well as the embryologic development of the thoracic organs. That information, as well as radiological and pathologic features of these lesions, is discussed in this review.

Fine-needle aspiration cytology of thymic basaloid carcinoma: Case studies and review of the literature

We report the features in fine-needle aspiration biopsy (FNAB) of thymic basaloid carcinomas. This is a rare neoplasm, of which there are only three documented in our hospital files. To the best of our knowledge, this is the first fine-needle aspiration (FNA) report on basaloid carcinoma of the thymus. This is a tumor in which the FNA diagnosis is difficult and the differential diagnosis is broad. We describe the cytologic features encountered in the three cases, and immunohistochemical and ultrastructural findings so as to raise awareness of this entity in the differential diagnosis of thymic neoplasms on FNABs. The cases studied included three male patients, aged 73, 65, and 50, who presented with anterior mediastinal masses, with no primary tumor elsewhere. FNAB was performed on two cases, followed by thymectomy. One case, additionally, had metastasis to a cervical lymph node, and the other two were associated with thymic cysts. The diagnoses on all three cases were thymic basaloid carcinoma.

Basaloid Carcinoma of the Thymus: Report of a Case

We report a case of basaloid carcinoma of the thymus, confirmed by histopathological examination, in a 52-year-old man who underwent complete resection. Local recurrence and lung metastases developed, which were obliterated by radiation therapy. The patient survived for 81 months after surgery. We reviewed the 13 other cases of basaloid carcinoma of the thymus reported in the literature. Presumably, this tumor is radiosensitive and its metastatic route is blood-borne.

Prise en charge des kystes thymiques

OBJECTIVE

The thymic cysts are rare tumors of the neck and anterior mediastinum. The management of these patients in our institution is reported. Minimally invasive procedures are discussed.

PATIENTS AND METHODS

Six patients operated in our institution within ten years, with a follow-up of 7.1 +/-3.7 years are studied retrospectively.

RESULTS

There were four women and two men with an average of 39.8 +/-16.5 years. The tumor was found on chest radiograph in four asymptomatic patients, one took medical advice for laryngeal discomfort and another for dysphagia and dyspnea. The tumor was localized in the anterior mediastinum in three cases, in the cervicomediastinal site in two cases and in the cervical site in one case. CT scan was practiced in three patients with a mediastinal tumor and MR imaging in one of them. In patients with cervical or cervicomediastinal tumor, a cervical echography was practiced. All patients were operated on: three by cervicotomy, one by sternotomy, one by partial upper mini-sternotomy and one by right lateral video-assisted mini-thoracotomy. Histology confirmed benign epithelial thymic cyst.

CONCLUSION

There is no specific marker of thymic cysts. Only the surgical management, leads to precise the diagnosis and to treat these tumors. No mortality, no complications or recurrences are reported. The minimally invasive surgery takes an interesting place for thoracic location, to explore and treat these benign mediastinal lesions.

Thymic basaloid carcinoma with hepatic metastasis

A thymic basaloid carcinoma is rare, as is an unusual case with extra-thoracic metastasis. We report on a 41-year-old woman who had a thymic basaloid carcinoma with liver metastases. The patient underwent resection of the thymic basaloid carcinoma followed by curative partial hepatectomy. At 1 year later, another metastatic lesion developed in the residual liver, which was also curatively resected. The postoperative course was uneventful, and the patient is surviving without recurrence for 12 months, to date.