Papillary Carcinoma of Thyroid Metastatic to AdenocarcinomaIn Situof Lung: Report of an Unusual Case

Abstract

The tumor-to-tumor metastasis is a rare event. The lung tumors are the most common donor tumors in tumor-to-tumor metastasis, but are exceedingly rare as a recipient. Here, we report a case of papillary thyroid carcinoma (PTC) metastasizing to adenocarcinoma in situ (AIS, formerly bronchioloalveolar carcinoma) of the lung in a 44-year-old woman who underwent total thyroidectomy for PTC 8 years ago. To the best of our knowledge, the present case is the first case reporting on PTC metastasized to AIS. A review of the relevant literature is presented.

Pulmonary metastasis of a papillary thyroid carcinoma and primary lung adenocarcinoma: two coincident carcinomas at the same location

“…Our case showed that the metastatic papillary thyroid adenocarcinoma foci were not limited to the primary lung adenocarcinoma and multiple microscopic foci of thyroid papillary foci were observed in the surrounding normal lung tissue. Multi foci of metastases can also be seen both within the lung cancer and in the background lung tissue in the 3 reported cases of a lung cancer acting as the recipient of a donor of papillary thyroid carcinoma [3-5]. In addition, multiple spreading small lung adenocarcinoma can also be seen in the background lung tissue in our present case while the 3 reported cases didn’t show this.…”

“…It is extremely rare that an aggressive malignant tumor as the recipient tumor while a low-grade malignancy as the donor tumor. Only three cases of papillary thyroid carcinoma, a low-grade malignancy, metastasizing to a lung cancer, an aggressive malignant tumor, were reported [3-5]. There were more reports about lung cancer metastasizing to a thyroid tumor [7-10].…”

“…To date, only 3 cases of lung cancer acting as the recipient of papillary thyroid carcinoma were reported in English-language literature. They were invasive adenocarcinoma, squamous cell carcinoma, and non-mucinous adenocarcinoma in situ , respectively [3-5]. Here we report a case that papillary thyroid carcinoma metastasized into a lung primary invasive adenocarcinoma, with multiple spreading foci of the two cancers in the lung simultaneously.…”

Tumour‐to‐tumour metastasis from papillary thyroid carcinoma with BRAF mutation to lung adenocarcinoma with EGFR mutation: the utility of mutation‐specific antibodies

“…In addition to our case, eight cases have been reported in which lung cancer was the recipient of tumour‐to‐tumour metastasis. In the present case and four of the previous cases, the donor tumour was papillary thyroid carcinoma . Of the remaining four cases, breast carcinoma was the donor in two cases and maxillary sinus adenoid cystic carcinoma was the donor in two cases (Table ) .…”

“…The incidence of cases in which lung cancer is the recipient is relatively low . To date, only eight cases of tumour‐to‐tumour metastasis into the lung have been reported in the English‐language literature …”