Metastatic mediastinal mature teratoma with malignant transformation in a young man with an adenocarcinoma in a Klinefelter's syndrome: Case report and review of the literature

Neuroendocrine Lesions Arising From Mediastinal Teratoma-A Case Report and Literature Review

Background. Neuroendocrine lesions arising from mediastinal teratomas are rare tumors with only small number of patients reported in literature. The behavior of these lesions appears to be different from traditional neuroendocrine neoplasms. A comprehensive review will be valuable for histologic assessment and treatment planning for similar cases. Case presentation. We present an example of a 57-year-old man who presented with cough. Subsequent work-up revealed an anterior mediastinal mass of 2.1 cm on computed tomography. The patient underwent robot-assisted thoracoscopic thymectomy. Histological examination revealed a mature cystic teratoma with a neuroendocrine component consisting of clusters of tumor cells with round to oval nuclei and a "salt-and-pepper" chromatin pattern. The tumor cells were immunoreactive to cytokeratin, synaptophysin, chromogranin, and INSM1, with a Ki-67 proliferative index of 4%. A histological diagnosis was mature teratoma with well-differentiated low-grade neuroendocrine tumor (carcinoid) was made. The patient was well and without disease after complete surgical excision at 10 months. Literature review. Literature reviewed yielded 13 examples of neuroendocrine lesions arising from mediastinal teratomas. No disease-related mortality was reported, even in lesions with high-grade neuroendocrine, carcinomatous, or immature teratomatous components. Conclusions. Surgical removal is the mainstay of treatment of these lesions, and the presence of a neuroendocrine component does not appear to negatively affect prognosis.

Sub-centimeter adenocarcinoma arising from mature mediastinal teratoma during 11 years of follow-up

A 54-year-old male presented with exertional dyspnea, right massive pleural effusion, and an anterior mediastinal tumor (6.5 × 6.2 × 7.6 cm) which continued to grow during the 11-year follow-up period. Fluorodeoxyglucose positron emission tomography demonstrated a focal but remarkable uptake within the tumor mass. After chest tube drainage, the patient underwent surgical resection via a right thoracotomy. The final pathology was determined to be a mature cystic teratoma with malignant transformation to adenocarcinoma. Teratomas with somatic-type malignancy are challenging to diagnose using only preoperative evaluations. Intra-operative findings, histopathological findings, and postoperative management techniques are discussed in this report and emphasize the importance of early resection for treatment of mature teratomas, as well as the recommendation of careful inspection of pathological specimens of long-standing teratomas.

Primary Mediastinal HER2-positive Apocrine Carcinoma in Mature Teratoma Treated With Anti-HER2 Therapy and Chemoradiation

BACKGROUND

There are no established guidelines for the management of apocrine carcinomas of the breast; they are treated as a non-specific type of breast cancer.

CASE REPORT

We report on the case of a 40-year-old man who developed primary mediastinal apocrine carcinoma overexpressing human epidermal growth factor-2 (HER2). The patient initially underwent complete resection of a mediastinal mature teratoma with a focal apocrine carcinoma component. Two years after surgery, relapse was detected in multiple mediastinal lymph nodes. He received induction chemotherapy including docetaxel, trastuzumab, and pertuzumab; consolidative concurrent chemoradiation was added after six cycles. A complete response was confirmed using computed tomography following this multimodal therapy. After chemoradiation, adjuvant trastuzumab and pertuzumab were administered for 1 year and the patient has since had no evidence of progressive disease.

CONCLUSION

A multi-modal regimen that includes an anti-HER2 agent appears to be a promising treatment for patients with HER2-positive extramammary apocrine carcinoma.