Primary pulmonary cancer colliding with metastatic choriocarcinoma

Gestational trophoblastic neoplasia with primary lung cancer and mesenchymal tumor of sigmoid colon: a case report and literature review

BACKGROUND

Gestational trophoblastic neoplasia (GTN) is rare, and it is even rarer for GTN to merge with primary malignant tumors in other organs. Herein is described a rare clinical case of GTN combined with primary lung cancer and mesenchymal tumor of the sigmoid colon, followed with literature review.

CASE PRESENTATION

The patient was hospitalized due to diagnosis of GTN with primary lung cancer. Firstly, two cycles of chemotherapy including 5-fluorouracil (5-FU) and actinomycin-D(Act-D) was given. Laparoscopic total hysterectomy and right salpingo-oophorectomy was performed during the third chemotherapy. During the operation, a 3*2 cm nodule was removed which was protruded from the serous surface of the sigmoid colon, and the nodule was confirmed mesenchymal tumor pathologically, in accord with gastrointestinal stromal tumor. During the treatment of GTN, Icotinib tablets were taken orally to control the progression of lung cancer. After 2 cycles of consolidation chemotherapy of GTN, she received thoracoscopic lower lobe of right lung lobectomy and the mediastinum lymph nodes removal. She undertook gastroscopy and colonoscopy and the tubular adenoma of the descending colon was removed. At present, the regular follow-up is taken and she remains free of tumors.

CONCLUSIONS

GTN combined with primary malignant tumors in other organs are extremely rare in clinical practice. When imaging examination reveals a mass in other organs, clinicians should be aware of the possibility of a second primary tumor. It will increase the difficulty of GTN staging and treatment. We emphasis the importance of the collaboration of multidisciplinary teams. Clinicians should choose a reasonable treatment plan according to the priorities of different tumors.

Collision tumors of the lung: A case report of urothelial carcinoma metastasizing to renal cell carcinoma with heterotopic ossification

Collision tumors are rare entities that consist of at least two or more histologically and ontologically distinct tumor types within the same organ. It is still not well understood how collision tumors form; yet, three main theories have been proposed to explain the pathogenesis, including the “random collision effect,” “field cancerization,” and “tumor-to-tumor carcinogenesis.” Collision tumors have been encountered in various body organs, including the lung. They either consist of a metastasizing tumor colliding with primary cancer or distinct primary or metastatic cancers colliding together. Here, we describe a rare case of collision tumors of the lung that consists of two metastatic carcinomas, namely renal cell carcinoma and urothelial carcinoma of the bladder. We propose that the urothelial carcinoma disseminated into several pre-existing pulmonary metastases of renal cell carcinoma with heterotopic bone formation. The possible mechanisms underlying the development of this peculiar tumor are discussed.