Thymic carcinoid tumors with bone metastases. A report of two cases

Increased carbohydrate antigen 19-9 expression in a thymic neuroendocrine tumor

Here, we report a case of carbohydrate antigen (CA) 19‐9‐producing mediastinal neuroendocrine tumor (NET) (atypical carcinoid). A 54‐year‐old woman with no specific relevant medical history was referred to our hospital because of increased CA19‐9 (95.3 U/ml) detected on health screening. Chest computed tomography (CT) revealed an anterior mediastinal mass without localized lymphadenopathy. Thoracic surgery was performed and the histopathological diagnosis was thymic CA19‐9‐positive NET. The patient developed mediastinal lymph node metastasis at 1 year (CA19‐9: 413 U/ml) and multiple bone metastases 4 years (CA19‐9: 2303 U/ml) after surgery. Increased CA19‐9 levels paralleled the clinical courses of relapse. To our knowledge, this is the first report of CA19‐9‐producing thymic NET.

Spinal Metastasis Resulting from Atypical Thymic Carcinoid: A Case Report

BACKGROUND

Thymic carcinoid with spinal metastasis is an extremely rare entity. Clinically, the tumor presents either by its endocrine manifestations or by mechanical compression of surrounding structures. However, no previously published case studies have reported neck pain and neurologic deficit in the initial presentation of an atypical thymic carcinoid.

CASE DESCRIPTION

A 56-year-old man, a nonsmoker, presented with a 12-month history of intermittent neck pain and a 1-month history of progressive numbness and weakness of the right upper limb. Cervical MRI showed multiple abnormal signals and C2 soft-tissue mass intruding into the vertebral canal. Cervical CT scan showed multiple bone lesions. The diagnosis of thymic carcinoid was obtained by preoperative lymph node biopsy. The patient underwent cervical laminectomy and occipitocervical fixation. Significant alleviation of pain and neurologic improvement were achieved. The postoperative pathological examination confirmed the diagnosis of thymic carcinoid.

CONCLUSIONS

Neck pain and neurologic deficit could be the first presentation of thymic carcinoid with spinal metastasis. Palliative surgery is an effective method to improve quality of life in patients with thymic carcinoid with spinal metastasis.

Thymic carcinoma initially presented with geographic destruction of scapula in a child

As the conventional histopathologic examination of thymic carcinoma (TC) is nonspecific, immunohistochemical studies along with correlative radiographic investigations are needed for its correct diagnosis. TC commonly occurs in the late 5th to early 6th decades of life but is extremely rare in childhood. It may be incidentally detected from chest radiographs taken as routine or for other reasons. However, most patients present with symptoms such as chest pain, cough, shortness of breath, dysphagia and hoarseness, which are directly attributable to the mediastinal mass. Although TC frequently invades the neighboring organs, pleura and pericardium and metastasizes to the lymph nodes, liver and lung at the time of the first diagnosis, initial or late metastasis to the bone has been seldom reported in adults. Indeed, the English literature revealed no earlier report on initial bony metastasis in a child to date. We report a case of TC in a 12-year-old boy who initially presented with scapular osteolysis masquerading as a primary bone tumor to emphasize the usefulness of combined imaging for staging and histologic studies, particularly for such an unexpected case.

Two Cases of Thymic Carcinoma Initially Presenting as Bone Metastasis: A Clinical Report and the Usefulness of CD5 Immunohistochemistry for Assessing Bone Lesions

Thymic carcinoma frequently spreads to the pleural space, regional lymph nodes, liver and lungs. However, an initial clinical presentation involving spinal or multiple bone metastases in patients with thymic carcinoma is extremely rare. We experienced two cases of thymic carcinoma that initially presented with spinal compression and severe pain due to multiple bone metastases, respectively. Both patients were histologically diagnosed with metastatic thymic squamous cell carcinoma based on the findings of specimens resected from the metastatic bone lesions. We herein describe the clinical courses of these cases and review the characteristics of bone metastasis of thymic carcinoma.