Multiple brain metastases from malignant thymoma

Dural venous sinus tumour thrombus from metastatic thymoma

Thymomas are the most common primary tumours of the anterior mediastinum. While intrathoracic disease progression through local invasion is well described in the literature, extrathoracic extension of disease is uncommon and intracranial metastases have seldom been reported. We present a case of extensive dural venous sinus tumour thrombus in a patient with metastatic invasive thymoma.

[Ileum and brain, unusual metastatic sites for a thymoma]

INTRODUCTION

Thymomas are epithelial neoplasms of thymic origin, preferentially localized in the anterior mediastinum. Recurrences after surgery are uncommon and usually occur in the intrathoracic area. The occurrence of extra-thoracic metastases is an unusual phenomenon.

CASE REPORT

Here we report the case of a 61-year-old man with no special medical history. He smoked about 40 pack years but stopped in 1999. Initially he presented with a mediastinal thymoma and underwent surgical resection. One year later the development of abdominal pain and bowel disorders lead to the discovery of an ileal ulcero-necrotic tumour. After surgical resection, histological examination revealed secondary thymoma. A few months later he underwent cerebral MRI because of neurological symptoms. This revealed a second metastasis located in the brain. Stereotactic radiotherapy led to an improvement. After more than one year of follow-up the patient developed a papillary thyroid carcinoma but there were no signs of recurrence of the thymoma.

CONCLUSIONS

Extra-thoracic metastases of thymoma are exceptional but their existence should not be overlooked. Their management is not standardised because of lack of data in the literature. Though surgical excision in oligo-metastatic subjects is a frequently reported therapeutic option, a radiotherapeutic approach, particularly in cerebral situations, could be a credible alternative.

A case of brain metastasis of a thymic carcinoma with a review of the literature

Thymic epithelial tumors (TET) are rare lesions. The brain metastases of these tumors are even rarer. We report a case of brain metastases in a known patient with a thymic carcinoma diagnosed in October 2016. She was a 73-year-old woman who presented with headache, nausea, and right hemiplegia. Brain MRI revealed five lesions (1 insular, 1 frontal and 2 left temporal, 1 right parafalcine). These lesions were initially treated using two stereotactic radiosurgery gamma knives. A macroscopically complete excision of the left frontal lesion was subsequently performed without any complications with a good evolution of the neurological symptoms postoperatively. Immunohistochemical examination was compatible with metastatic thymic carcinoma. The patient died 14 months after the initial diagnosis. A review of the literature in English has reported another 45 TET cases with brain metastases.

Thymic epithelial tumors and metastasis to the brain: a case series and systematic review

Background

Thymic epithelial tumors (TETs) rarely metastasize to the brain. Clinico-pathologic features of TET patients with brain metastasis are not well described.

Methods

TET patients referred for consultation or screening for clinical trials are included. Imaging to evaluate for brain metastases was performed when clinically indicated or if required for screening. Tumor tissue from brain metastases was obtained for analysis, when available. Clinical characteristics and survival was evaluated and a systematic review of the literature on brain metastases associated with TETs was performed.

Results

Fourteen TET patients with brain metastasis were identified. Median age at TET diagnosis was 53 years (range: 31-71 years). Twelve patients had thymic carcinoma and two patients had World Health Organization B3 thymoma. Median time from TET diagnosis to discovery of brain metastases was 2.5 years (range: 9 months-8.3 years). Eleven patients had extracranial, extrathoracic metastases during presentation with brain metastases. Three patients underwent surgery and radiation therapy, eight patients received radiation therapy alone, and one patient had surgery alone. One patient with thymoma died 11 months after diagnosis of brain metastases and another patient died but with unknown date of diagnosis of brain metastases. Among 12 patients with thymic carcinoma, 11 of whom had a known date of brain metastases diagnosis, the median potential follow-up is 35.8 months, and median overall survival (OS) from diagnosis of brain metastases is 13.1 months.

Conclusions

Although uncommon, patients with advanced thymic carcinoma can develop brain metastases. Appropriate imaging and aggressive treatment should be considered for these patients.

AB thymoma with atypical type A component with delayed multiple lung and brain metastases

An atypical type A thymoma is a newly added entity to the last World Health Organization (WHO) histological classification [2015] of uncertain prognosis. The conventional type A and AB thymomas are usually locally aggressive neoplasms that rarely metastasize with distant metastases to the central nervous system (CNS) occurring extremely exceptionally. We present a history of a woman with a mediastinal tumor originally considered to be a Masaoka-Koga stage II "mixed thymoma with well-differentiated thymic carcinoma component" according to the historic Müller-Hermelink nomenclature. By applying the criteria of the new WHO classification the tumor should be reclassified as an AB thymoma with an atypical A component. The patient developed metastases to the lung and brain 10 and 15 years after the original diagnosis, respectively. All metastases morphologically corresponded to an atypical A component of primary thymoma. Molecular study revealed GTF2I mutations in the primary and one of the metastatic tumors. To our knowledge, this is the first description of a GTF2I mutation in AB thymoma with atypical A component and its metastases. The presented case highlights the necessity of an accurate microscopic search for atypical areas in A or AB thymomas because of their potentially negative impact on prognosis.

Metastatic Thymic Carcinoma Presenting as a Posterior Fossa Mass: Case Report and Review of the Literature

BACKGROUND

Thymic epithelial tumors (TETs) are uncommon lesions, and cerebral metastases from these tumors are even rarer. We report a case of a posterior fossa metastasis in a patient with a known history of thymic carcinoma.

CASE DESCRIPTION

A 47-year-old man with a history of Hodgkin lymphoma and thymic carcinoma presented with headache, nausea, and ataxia. Imaging revealed a large posterior fossa mass. This lesion was completely resected without complications. Pathologic examination was consistent with metastatic thymic carcinoma. The patient's symptoms were relieved postoperatively. We reviewed the literature and identified an additional 44 cases of TETs with metastases to the brain. Although brain metastases are generally associated with a poor prognosis in patients with TETs, survival of more than 1 year may be accomplished with surgical resection and multimodality treatment.

CONCLUSIONS

Metastasis should be considered in the differential of a patient with a TET and an intracranial mass lesion.

Invasive thymoma metastatic to the cavernous sinus

Background:

Thymomas are typically benign tumors of thymic epithelium. Metastases to distal sites, particularly intracranial locations, are extremely rare. Herein, we present the third case of thymoma and the second invasive thymoma to metastasize to the cavernous sinus, adjacent to the pituitary.

Case Description:

A 41-year-old female patient presented with headaches, stuffy nose, and drooping of the right face. A magnetic resonance imaging scan revealed a complex, multilobulated mass centered upon the right cavernous sinus. The mass was removed via transsphenoidal surgery, and histopathological investigation confirmed the diagnosis of metastatic thymoma. A positron emission tomography-computed tomography scan demonstrated a large anterior mediastinal mass. A biopsy confirmed the diagnosis of invasive thymoma morphologically identical to the World Health Organization type B2 sellar region metastasis.

Conclusion:

Although rare, thymomas can metastasize to the central nervous system. Our case is the second invasive thymoma to metastasize to the cavernous sinus, adjacent to the pituitary.

Cystic brain metastases radiologically simulating neurocysticercosis

CONTEXT

Brain metastases are common complications of cancer. Magnetic resonance imaging (MRI), the main diagnostic imaging method in these cases, rarely shows cystic images.

CASE REPORT

The patient was a 45-year-old woman who had had severe headache for a month that was refractory to medication, and had previously had breast cancer, which had been treated. The MRI showed the criteria for neurocysticercosis. Since there was no improvement with clinical treatment, we chose to excise the lesions. Histopathological analysis showed an epithelioid malignant neoplasm.

CONCLUSION

From immunohistochemical analysis, it was concluded that this was a metastasis of breast carcinoma. Even when the MRI is not characteristic of cerebral metastasis, this hypothesis needs to be ruled out in patients with a previous history of cancer.

Brain metastasis from thymic carcinoma in association with SIADH and pituitary enlargement: a case report

A 49-year-old white female presented to the emergency room complaining of severe headaches. A brain computed tomography (CT) showed a large right temporal mass that measured 2.9 x 5 cm. Sodium was low at admission, which indicated syndrome of inappropriate secretion of antidiuretic hormone (SIADH). Her pituitary gland was enlarged. Thorax CT revealed a large anterior mediastinal mass measuring 6.3 x 3.6 cm. Pathology revealed a poorly differentiated carcinoma arising from the thymus. This case is unique because thymic cancer rarely results in brain metastases and very rarely causes SIADH with changes in pituitary volume and signal quality.