No abstract

Goblet cell carcinoid (GCC) of the appendix is now regarded as a malignant tumor, and mixed adenoneuroendocrine carcinoma (MANEC) is a carcinoma progressing from GCC. We describe a man initially diagnosed with GCC of the appendix who died 4 years after diagnosis. Pleural fluid due to metastasis was noted in the terminal phase. Histological findings of the initial tumor indicated that cells with signet-ring morphology were predominant, but the cytological morphology of the fluid was more atypical, making it difficult to diagnose as metastatic GCC by cellular morphology alone. The cells in the pleural fluid were immunopositive for synaptophysin, which was compatible with GCC, but p53 and ki67 staining indicated that the metastatic tumor was more aggressive. These findings suggested a final diagnosis of poorly differentiated adenocarcinoma-type MANEC, which we define as a tumor with typical GCC characteristics and foci that cannot be distinguished from a poorly differentiated adenocarcinoma. This case, which we believe is reported here for the first time, indicates the cytological features of GCC cells may change at metastatic sites to be more atypical and aggressive as the tumor progresses, and these changes should be considered in diagnosis.

Neurofibromatosis type 1 (NF1) is a common inherited disorder with an autosomal dominant trait. We encountered an NF1 patient who showed adrenal pheochromocytoma, and analyzed expression of neurofibromin in an excised specimen. A 54-year-old man showing multiple neurofibromas and café-au-lait spots in the skin was pointed out to have a right adrenal tumor by ultrasonography. Abdominal CT also revealed a right adrenal tumor. He was diagnosed with neurofibromatosis type 1 with no family history. Urine catecholamines, metanephrine, and normetanephrine levels were elevated. MIBG scintigraphy showed positive right adrenal uptake, and so pheochromocytoma was also diagnosed. The patient underwent laparoscopic right adrenalectomy. The excised adrenal specimen of this patient was stained with anti-neurofibromin polyclonal antibody. The NF1 pheochromocytoma was completely negative for neurofibromin protein expression, while the NF1 non-pheochromocytomatous adrenal medulla was neurofibromin-positive in the cytoplasm and nucleus. The clear discrepancy in neurofibromin expression between pheochromocytoma cells and "normal" adrenal medullary cells of the patient may well be explained by Knudson's twohit hypothesis.

High mobility group box (HMGB) proteins are nuclear nonhistone chromosomal proteins that bend DNA, bind preferentially to distorted DNA structures, and promote the assembly of site-specific DNA binding proteins. Recent reports indicate that HMGB1 has a dual function, a cytokine in addition to a nuclear protein. The increased expression of HMGB1 has been reported for several different tumors. Here, we assessed HMGB1 and HMGB2 expressions in two cases of papillary renal cell carcinoma. One case with pT1a, Grade 2 showed HMGB1 expression in the nucleus and cytosol and HMGB2 expression in the nucleus, but not in the cytosol. In the other case, there were three renal tumors, one of which was clear cell renal cell carcinoma with pT1a, Grade 3 and two were papillary renal cell carcinomas, Grade 2 (5 mm and 2 mm in the diameter). Both HMGB1 and HMGB2 were expressed in the nucleus and cytosol of papillary carcinoma. In the clear cell carcinoma of this case, HMGB1 expression was stained both in the nucleus and cytosol, while HMGB2 was observed in the nucleus, but not in the cytosol. More samples need to be further investigated in order to draw conclusions concerning HMGB expressions in papillary renal cell carcinomas.