Case reports of collision and composite carcinomas of the thyroid: an insight into their origin and clinical significance

BACKGROUND

Collision and composite carcinomas of the thyroid are extremely rare, and their clinical and biological characteristics are poorly understood.

CASE PRESENTATION

The first case was a 41-year-old female patient with a right thyroid nodule. Pathological diagnosis was papillary thyroid carcinoma (PTC) and medullary thyroid carcinoma composite carcinoma. Surgical treatment was right thyroid lobectomy + left partial thyroidectomy + right central neck lymph node dissection. The second case was a 60-year-old female with bilateral thyroid nodules. Total thyroidectomy was performed, and the pathological diagnosis was thyroid collision carcinoma involving follicular thyroid carcinoma on the left side and PTC on the right side. The clinical, histological and gene changes of collision and composite carcinomas of the thyroid are poorly described. With different biological invasion characteristics, the ideal treatment and the prognosis is currently unknown and individualized treatment is necessary.

CONCLUSIONS

It is recommended that in composite carcinoma, each cancer is evaluated and treated according to the most severe tumor. Collision carcinoma should be treated as two separate synchronous primary tumors. For both collision and composite carcinomas of the thyroid, the follow-up after treatment should be extensive.

Mixed adenoneuroendocrine carcinoma of the ampulla: Two case reports

Mixed adenoneuroendocrine carcinoma (MANEC) is a malignant tumor with adenocarcinoma and neuroendocrine components, with ≥ 30% of each component required. MANEC of the ampulla is rare. To the best of our knowledge, only 15 cases of MANEC of the ampulla have been reported in the English-language literature. Here, we report two cases of MANEC of the ampulla in two women aged 43 and 60 years, which was confirmed by histology after pancreaticoduodenectomy. These tumors contained neuroendocrine and adenocarcinoma components. The neuroendocrine components were positive for chromogranin A (CgA), synaptophysin (Syn) and CD56 by immunostaining. The adenocarcinoma components were negative for CgA, Syn and CD56. Both cases were T3N0M0 (Stage IIIA). They survived for 15 and 20 mo after surgery, respectively. A brief discussion about the histopathological features, clinical behavior and treatment of MANEC of ampulla, and review of the relevant literature are presented.

Neuroendocrine and squamous colonic composite carcinoma: Case report with molecular analysis

Composite colorectal carcinomas are rare. There are a modest number of cases in the medical literature, with even fewer cases describing composite carcinoma with neuroendocrine and squamous components. There are to our knowledge no reports of composite carcinoma molecular alterations. We present a case of composite carcinoma of the splenic flexure in a 33 year-old Caucasian male to investigate the presence and prognostic significance of molecular alterations in rare colonic carcinoma subtypes. Formalin-fixed paraffin-embedded (FFPE) tissue was hematoxylin and eosin- and mucicarmine-stained according to protocol, and immuno-stained with cytokeratin (CK)7, CK20, CDX2, AE1/AE3, chromogranin-A and synaptophysin. DNA was extracted from FFPE tissues and molecular analyses were performed according to lab-developed methods, followed by capillary electrophoresis. Hematoxylin and eosin staining showed admixed neuroendocrine and keratinized squamous cells. Positive nuclear CDX2 expression confirmed intestinal derivation. CK7 and CK20 were negative. Neuroendocrine cells stained positively for synaptophysin and AE1/AE3 and negatively for chromogranin and mucicarmine. Hepatic metastases showed a similar immunohistochemical profile. Molecular analysis revealed a G13D KRAS mutation. BRAF mutational testing was negative and microsatellite instability was not detected. The patient had rapid disease progression on chemotherapy and died 60 d after presentation. Although the G13D KRAS mutation normally predicts an intermediate outcome, the aggressive tumor behavior suggests other modifying factors in rare types of colonic carcinomas.

Composite neuroendocrine and adenomatous carcinoma of the papilla of Vater

Malignant tumors of papilla are usually adenocarcinomas. We present a 67-year-old female who became icteric as result of a malignant tumor infiltrating the papilla of Vater. Histopathological assessment of surgically excised tumor showed both neuroendocrine and adenocarcinomatous features. To our knowledge, this is the seventh report of this rare neoplastic association in the duodenal periampullary region.