Neuroendocrine tumors (carcinoid) of the thymic gland

[Primary Neuroendocrine Carcinoma of Thymus Caused Cushing Syndrome: Surgical Treatment and Prognosis Analysis]

背景与目的

胸腺原发神经内分泌癌为一种罕见疾病，部分肿瘤可以分泌促肾上腺皮质激素导致库欣综合征，手术切除肿瘤是治疗的关键。本研究回顾性总结并探讨胸腺原发神经内分泌癌所致库欣综合征临床诊断及手术治疗方法，并行预后分析，提高对此罕见病种的认识及诊疗水平。

方法

回顾性分析北京协和医院1987年11月-2013年6月间收治的14例由胸腺原发神经内分泌癌导致的库欣综合征患者的临床资料。

结果

14例患者，男性8例，女性6例，中位年龄29岁，中位病程4.0个月(1个月-44个月)，术前多项内分泌检查及影像学检查诊断并定位胸腺病变，经手术切除后血皮质醇及血促肾上腺皮质激素均下降(P < 0.01)。围手术期死亡1例。经术后综合治疗及随访，中位生存期为38个月。

结论

胸腺原发神经内分泌癌所致库欣综合征为一种罕见疾病，侵袭性强，目前治疗效果欠佳。早期诊断及早期治疗对临床医师而言存在很大难度，胸部增强计算机断层扫描(computed tomography, CT)是诊断并定位的重要手段，需要多种检查手段及多学科医师共同会诊并制定以手术为主的综合诊治方案。

Anterior approach for Pancoast tumor resection

Tumors arising anteriorly in the apex of the chest were long considered unresectable because of early invasion of vascular structures limiting radical resection through the conventional Paulson approach. These tumors became operable in 1993 when Dartevelle popularized the cervico-thoracic transclavicular technique for resecting these neoplasms. Since then several different surgical approaches to anterior Pancoast tumors have been proposed, drastically improving the rate of radical resections of these tumors. However, there is no consensus on which anterior surgical approach provides the best access to all of the apical non-small cell lung cancers of the thoracic inlet. Moreover, it is still unclear if integrated neoadjuvant and adjuvant treatments can improve the rates of complete resection, local recurrence and long-term survival.

Neuroendocrine ACTH-producing tumor of the thymus--experience with 12 patients over 25 years

CONTEXT

ACTH-producing neuroendocrine tumor (NET) of the thymus is a rare cause of Cushing's syndrome (CS). The literature consists mainly of isolated case reports.

PATIENTS

We studied 12 cases (eight males and four females) diagnosed between 1986 and 2010 with CS and thymic NET who underwent surgical resection.

MAIN OUTCOME MEASURES

We measured time from onset of CS to diagnosis of thymic NET, tumor size, histological grade, time to recurrence, and survival and performed a meta-analysis of other published cases of CS associated with thymic NET.

RESULTS

Eleven of 12 patients presented with classic features of CS at a median age of 21 yr (range, 7-51). Four were children. The 24-h urine free cortisol was greater than 16-fold of normal, and biochemical testing was consistent with ectopic ACTH production in all 11. Another patient presenting with pulmonary embolus had a thymic mass and was later diagnosed with CS. All patients underwent thymectomy, and nine of 10 tumors exhibited positive ACTH immunochemistry. Median tumor diameter was 5 cm (range, 1-11.5). Six patients recurred 20-28 months after surgery with metastases to mediastinal lymph nodes (n = 5), bone (n = 5), liver (n = 1), parotid gland (n = 1), and breast (n = 1). Four of five patients treated with radiation therapy also received chemotherapy. All recurrent patients received ketoconazole; four later underwent bilateral adrenalectomy. Six recurrent patients died 22-90 months (median, 57) after thymectomy. At last review, six patients were alive 14-90 months (median, 49) after thymectomy. These data are similar to those from the meta-analysis.

CONCLUSIONS

Thymic ACTH-producing NET is an aggressive disease that should be considered in CS with ectopic ACTH secretion, particularly in younger patients.

Clinicopathological analysis of 21 thymic neuroendocrine tumors

BACKGROUND

Thymic neuroendocrine carcinomas (NECs) are uncommon, for which there is no established information available because of a limited number of epidemiological study in Asia.

METHODS

We reviewed 21 cases of surgically resected thymic NECs, and evaluated their pathological and clinical features.

RESULTS

It showed male predominance (male/female ratio, 15/6) with wide age range from 20 to 72 years (mean age, 49 years). All 21 cases were divided into two types according to the World Health Organization criteria: atypical carcinoid (n=18) and large cell NEC (n=3). Three cases of atypical carcinoid (AC) were associated with ectopic Cushing's syndrome. All the patients (3/3) with large cell NEC (3/3) and 16.7% (3/18) of those with AC died of tumor progression. Common sites of metastasis included lung, lymph node, brain, lumbar spine, mediastinum, bone, and liver.

CONCLUSIONS

In conclusion, thymic neuroendocrine tumors carry a poor prognosis. Regarding the tumor classification, our results showed that a vast majority of carcinoids in the thymus correspond to ACs. In addition, our results also indicate that typical carcinoid is a very rare entity. Some cases of AC exhibited a large size, solid pattern and they showed aggressive clinical behavior, which highlights the spectrum of histologic appearances of thymic NECs.