CT and MRI findings of thymic carcinoid

Abstract

Objective: To evaluate the CT and MRI findings of thymic carcinoid and to compare these findings with previously published findings of thymoma. Methods: 11 cases of pathologically proven thymic carcinoid were reviewed retrospectively. Three patients had typical carcinoid, and eight patients had atypical carcinoid. The characteristics of the tumours and related thoracic abnormalities were assessed in each case on CT and/or MRI by two chest radiologists. The final decisions on the findings were reached by consensus. Results: Thymic carcinoids were more likely to have a large mass (ranging from 18 to 105 mm), irregular contours (n 5 8), heterogeneous intensity on T 2 weighted images (n 5 6; eight patients underwent MRI), heterogeneous enhancement (n 5 9) and local invasion (n 5 7).A necrotic or cystic component was identified in seven patients (one typical carcinoid and six atypical carcinoids). Lymphadenopathy was seen in four patients. Septum, capsule, haemorrhage and calcification were seen in three patients, two patients, two patients and one patient, respectively, with atypical carcinoid. Conclusion: Thymic carcinoids tend to have a high prevalence of large masses, irregular contours, heterogeneous intensity on T 2 weighted images, heterogeneous enhancement and local invasion on CT and/or MRI. A necrotic or cystic component is often seen in atypical carcinoid. Advances in knowledge: Radiologic features of thymic carcinoid mimic those of high-risk thymomas and/or thymic carcinomas.

Relationship Between Computed Tomography Imaging Features and Clinical Characteristics, Masaoka–Koga Stages, and World Health Organization Histological Classifications of Thymoma

“…This study found that contour, abutment ≥50%, and adjacent lung abnormalities were risk factors for postoperative recurrence or metastasis upon logistic regression analysis. These findings are somewhat similar to previous results (7, 18, 21, 49, 50). However, some studies reported that tumor size or histological subgroups were related to postoperative recurrence or metastasis (19, 25, 26).…”

Comparative study of computed tomography of normal and lymphoid follicular hyperplasia thymus in myasthenia gravis patients

“…This result may possibly indicate a different mechanism between younger and older MG patients (25). In fact, the observation that there were no significant differences between the two groups in six views of the thymus exactly coincides with the fact that the autoimmune LFH thymus is characterized by a normal size and weight, including those of lymphoid follicles (24).…”

“…However, it is known that when the involution starts, the epithelial component of the thymus atrophies, resulting in scattered small lymphocytes in abundant adipose tissue (18,19,22). LFH, also known as autoimmune thymitis, is characterized by a normal size and weight of the thymus with chronic inflammation and proliferation of lymphoid follicles, active germinal centers and increased numbers of lymphocytes and epithelial cells (23,24). The symptoms of MG, including the impairment of ocular (extra-ocular muscles, eyelids), bulbar (ingestion function, voice/speech function, respiratory function, facial muscles) and limb-axial muscles (arms, legs and neck), always improve after thymectomy in patients with thymoma or LFH thymus (5)(6)(7)(8).…”

Tumor carcinoide atípico solitario de timo: Una entidad inusual que no debemos olvidar

“…En relación con los hallazgos imagenológicos de resonancia encontramos que la lesión en mediastino anterior descrita presentaba señal levemente heterogénea y pequeñas áreas hiperintensas (por probable microsangrados) en secuencia T1 sin contraste. Tras la administración de gadolinio presenta realce intenso y de forma irregular en secuencia T1 2,4 .…”