Lubana Sandeep Singh, Singh Navdeep, Tuli Sandeep S, Bashir Tayyaba, Sachmechi Issac, Kemeny Margaret M
Department of Internal Medicine, Icahn School of Medicine at Mount Sinai, Queens Hospital Center, Queens, NY, USA.
Department of Radiology, Icahn School of Medicine at Mount Sinai, Queens Hospital Center, Queens, NY, USA.
Am J Case Rep. 2015 Jul 16;16:459-68. doi: 10.12659/AJCR.894935.
Follicular variant of papillary thyroid cancer (FV-PTC) is the second most common subtype of papillary thyroid cancer (PTC) after classic PTC. FV-PTC is characterized by nuclear features consistent with classic PTC but has a follicular architecture that lacks classic papillary morphology. Thyroid cancer rarely metastasizes to the kidney. Only 6 cases of FV-PTC metastasizing to the kidney have been reported in the English literature. We are reporting a case of FV-PTC with bilateral renal metastases discovered incidentally during work-up of primary endometrial cancer.
A 70-year-old woman presented with post-menopausal bleeding secondary to endometrial cancer. Staging work-up showed multiple bilateral lung nodules, bilateral soft tissue kidney masses, and multinodular goiter. The pathological and immnohistochemical profile of the lung biopsy was consistent with primary well-differentiated lung adenocarcinoma. Follow-up computerized tomography scan showed stable lung nodules and enlarging renal masses, which was suggestive of bilateral renal cancer. While the histologic features of the renal biopsy were not typical, the immunohistochemical staining of renal biopsy was positive for Paired box 8, thyroid transcription factor-1, thyroglobulin, and cytokeratin 7, suggesting the thyroid as the primary cancer site. The final histopathology on surgical specimen of total thyroidectomy revealed follicular variant of papillary thyroid cancer.
The presence of pulmonary nodules and kidney masses does not always suggest the lung or the kidney as primary tumor sites. The clinician should be aware of the possibility of metastasis and look for the primary source, which in the present case was FV-PTC. Immunohistochemistry plays an important role in determining the primary site of origin. In case of multiple-organ metastases, each metastatic lesion should be biopsied as soon as possible for definitive diagnosis and appropriate treatment.
甲状腺乳头状癌滤泡亚型（FV-PTC）是继经典型甲状腺乳头状癌（PTC）之后第二常见的PTC亚型。FV-PTC的特征是具有与经典PTC一致的核特征，但具有缺乏经典乳头状形态的滤泡结构。甲状腺癌很少转移至肾脏。英文文献中仅报道了6例FV-PTC转移至肾脏的病例。我们报告1例在原发性子宫内膜癌检查过程中偶然发现的伴有双侧肾转移的FV-PTC病例。
一名70岁女性因子宫内膜癌出现绝经后出血。分期检查显示双侧肺部多个结节、双侧肾脏软组织肿块和多结节性甲状腺肿。肺活检的病理和免疫组化结果与原发性高分化肺腺癌一致。后续计算机断层扫描显示肺部结节稳定，肾脏肿块增大，提示双侧肾癌。虽然肾活检的组织学特征不典型，但肾活检的免疫组化染色显示配对盒8、甲状腺转录因子-1、甲状腺球蛋白和细胞角蛋白7呈阳性，提示甲状腺为原发癌部位。全甲状腺切除手术标本的最终组织病理学检查显示为甲状腺乳头状癌滤泡亚型。
肺部结节和肾脏肿块的存在并不总是提示肺或肾脏为原发肿瘤部位。临床医生应意识到转移的可能性并寻找原发灶，本例中的原发灶为FV-PTC。免疫组化在确定原发起源部位方面发挥重要作用。在出现多器官转移的情况下，应尽快对每个转移病灶进行活检以明确诊断并进行适当治疗。
