Pancreatic metastasis of malignant melanoma diagnosed by EUS-guided fine needle aspiration (EUS-FNA)]

Pancreatic metastasis of malignant melanoma is rarely diagnosed while the patient is alive. We report a case of metastatic melanoma of the pancreas in a 35-year-old woman presenting with a solid mass of the pancreas. Her past medical history included a radical hysterectomy 2 years previously for malignant melanoma of the vagina. Twelve months later, lung metastasis was also resected. EUS-guided fine needle aspiration (EUS-FNA) identified that the pancreatic tumor was histologically and immunohistochemically identical to the surgical specimen of her lung neoplasm. Imaging studies including US, CT, and MRI have limited value to distinguish the tumors from primary ductal adenocarcinoma. EUS-FNA can provide tissue diagnosis from pancreatic masses, specifically when other modalities have failed.     

TWO CASES OF ACQUIRED TOXOPLASMIC LYMPHADENITIS. Light and Electron Microscopic and Immunohistochemical Studies

We report two cases of acquired toxoplasmic lymphadenitis, one with toxoplasmic cysts and the organisms of Toxoplasma gondii and the other with the organisms only. These cysts and organisms were observed in paraffin-embedded sections, touch smears and ultrathin sections for electron microscopy. Touch smears were especially valuable for the quick and accurate diagnosis of toxoplasmic lymphadenitis. We also studied immature sinus histiocytosis (ISH) in these cases. The predominant cells of ISH were confirmed to be B lymphocytes immunohistochemically, the majority being positive for polyclonal surface IgM. ISH was observed in the perifollicular and paracortical areas surrounding post-capillary venules (PCV), whereas the sinuses were only partially involved.     

Undifferentiated Carcinoma of the Parotid Gland in a 10-Month-old Child

Malignant salivary gland tumors in children are very rare. This report describes the autopsy of a child with parotid gland cancer. The patient, a 10 month old girl, was admitted to the Nagoya First Red Cross Hospital with facial nerve palsy. lncisional biopsy of a post-auricular tumor was performed, and undifferentiated carcinoma was diagnosed. The patient died 6 months later of respiratory failure due to pulmonary lymphangitis carcinomatosis. Light and electron microscopic and immunohistochemical examinations of the tumor tissue were performed. The tumor cells were arranged in a medullary, sheet-like manner. Keratinization or mucus lakes were not observed. PAS-alcian blue staining demonstrated intracytoplasmic mucus as granules, and also small intercellular droplets of mucus that might otherwise have been unnoticed. Ultrastructurally, some of the tumor cells had tonofilament-like keratin filaments, and also small hollow spaces bounded by microvilli and containing secretory particles. These were stained by antisera against CEA and keratin. These findings are suggestive of differentiation to mucoepider-moid carcinoma. We also review and discuss malignant salivary tumors of epithelial origin in children. Acta Pathol Jpn 40: 149–152, 1990.     

Outcome of advanced renal cell carcinoma arising in end-stage renal disease: comparison with sporadic renal cell carcinoma

Clinical and Experimental Nephrology - The data regarding oncological outcome in advanced renal cell carcinoma (RCC) arising in end-stage renal disease (ESRD) are limited. Patients diagnosed with...     

Double-injection method for sequentially measuring cerebral blood flow with N-isopropyl-(123I)p-iodoamphetamine

We investigated the accuracy of a double-injection method for sequentially measuring cerebral blood flow (CBF) with N-isopropyl-(123I)p-iodoamphetamine (IMP) in simulation studies based on patient data and in clinical studies. The unidirectional clearance of IMP from the blood to the brain (K1; nearly equal to CBF) in the first and second sessions was calculated by means of a microsphere model. The K1 values in the first session (K1I) were calculated from Cb(5)/Int_CaI, where Cb(5) and Int_CaI are values for brain radioactivity 5 min after the first injection and for arterial blood radioactivity obtained by 5-min continuous sampling. The K1 values in the second session (K1II) were calculated by means of the following four methods. Method 1: [Cb(tz + 5) - Cb(tz)]/[Int_CaII - Ca(tz) x 5], where Cb(tz+5) and Cb(tz) are the brain radioactivity levels 5 min after the second injection and at the time the second session was started (tz), respectively. Int_CaII and Ca(tz) are the arterial blood radioactivity levels obtained by 5-min continuous sampling after the second injection and at tz, respectively. Method 2: [Cb(tz + 5) - Cb(tz)]/[Int_CaI x R], where R is the injection dose ratio. Method 3: [Cb(tz + 5) - Cb(tz) x exp(- K1I x 5/lambda)]/Int_CaII, where lambda is the population averaged partition coefficient. Method 4: same as Method 3 except that K1I was replaced by K1II obtained by means of Method 2. Theoretically, Method 4 appeared to be the best of the four methods. The change in K1 during the second session obtained by Method 1 or 2 largely depended on R and tz, whereas Method 3 or 4 yielded a more reliable estimate than Method 1 or 2, without largely depending on R and tz. Since Method 2 was somewhat superior to other methods in terms of noninvasiveness and simplicity, it also had the potential for routine clinical use. The reproducibility of two sequential measurements of K1 was investigated with clinical data obtained without any intervention. The response of CBF to acetazolamide challenge was also assessed by the above four methods. The knowledge gained by this study may assist in selecting a method for sequentially measuring CBF with a double injection of IMP.     

Controlled self-assembly into diverse stimuli-responsive microstructures: from microspheres to branched cylindrical micelles and vesicles

A series of amphiphilic PDMAEMA–SS–PCL chains with variable ratios of hydrophilic poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) to hydrophobic poly(ε-caprolactone) (PCL) were prepared via ring-opening polymerization, in which the two different moieties were linked via a disulfide bond with reduction responsiveness. After cross-linking by the photodegradable o-nitrobenzyl linkage, the amphiphilic chains could self-assemble into microspheres, branched cylindrical micelles and vesicles, which were responsive to the reduction agent dl-dithiothreitol and UV light irradiation through different mechanisms.

A series of cross-linked amphiphilic PDMAEMA–SS–PCL were prepared, which could self-assemble into diverse microstructures with reduction and light responsiveness.