Pathology International

Lu, Jian‐ping; Hayashi, Keiki; Okada, Shigeru; Awai, Michiyasu

doi: 10.1111/j.1440-1827.1991.tb02787.xpmid: 1776464

Iron overload was produced in Wistar rats by repeated intraperitoneal injections of ferric nitrilotriacetate (Fe3+‐NTA) for one to six months. Pancreatic tissues from these iron‐overloaded rats and untreated controls were examined for insulin (for B cells), glucagon (for A cells), transferrin receptor (TfR), transferrin (Tf) and ferritin (Ft) using immunohistochemical methods, and for iron by histochemical Berlin blue staining. In the islets of iron‐overloaded rats, increased Ft staining appeared prior to deposition of Berlin blue‐stainable iron, and the staining intensity of Ft and iron was stronger in B cells than in A cells. In the islets of untreated control rats, the staining intensity of TfR was stronger in B cells than in A cells. TfR staining of the islets was weaker in iron‐overloaded rats than in the controls. These findings suggest that 1) iron uptake by islet cells in vivo is regulated and mediated by TfR, 2) intracytoplasmic Ft transforms into stainable iron in iron‐overloaded rats, and 3) predominance of TfR expression in B cells may result in selective deposition of iron and predispose B cells to damage and diabetes mellitus in iron‐overloaded rats. Acta Pathol Jpn 41: 647–652, 1991.

Ishitobi, Fumio; Sagiya, Atsushi; Oka, Kazuo; Ueda, Yoshihiko; Takimoto, Toshiro; Ono, Yuko; Kanaya, Hiroaki; Yaguchi, Tadashi; Lidaka, Kazunari; Tauchi, Kiyonori

doi: 10.1111/j.1440-1827.1991.tb02788.xpmid: 1776465

Nagahama, Masato; Kashiwai, Akiko; Kadota, Chika; Tsutsui, Yoshihiro

doi: 10.1111/j.1440-1827.1991.tb02789.xpmid: 1663688

To investigate the pathogenesis of brain abnormalities caused by congenital cytomegalovirus (CMV) infection, we previously reported experimental murine models of brain damage induced by intraventricular injection of murine CMV (MCMV) at the late stage of gestation. In the present study, viral DNA‐positive cells in the damaged brain at different postnatal stages detected by in situ hybridization were compared with viral antigen‐positive cells detected by an immunoperoxidase method using a monoclonal antibody against the immediate early antigen. At birth, the number of viral DNA‐positive cells almost equalled that of viral antigen‐positive cells. Seven to ten days after birth, the number of viral DNA‐positive cells in the brain of MCMV‐injected mice was one‐fifth that of viral antigen‐positive cells. Viral DNA‐positive cells were more numerous in the hippocampus than in the cortex, and their density was dependent on the presence of viral antigen‐positive cells. Dotted reaction products were observed in the nuclei of viral DNA‐positive cells. These cells were rarely detected in lesions of later stages such as atrophy of the cortex and hippocampus, or the wall of the cystic lesions. These results suggest that viral DNA‐positive cells detected by in situ hybridization are infected cells in which viral DNA replication is occurring actively. Acta Pathol Jpn 41: 661–667, 1991.

Sano, Nobuya; Izumi, Keisuke

doi: 10.1111/j.1440-1827.1991.tb02790.xpmid: 1663689

Hepatic involvement of cytomegalovirus (CMV) was studied in 15 autopsy cases with disseminated or solitary CMV infection. Formalin‐fixed, paraffin‐embedded tissue sections were examined by immunohistochemistry (IHC) using a monoclonal antibody against early and late CMV antigens, and by in situ hybridization (ISH) using biotinylated CMV DNA probes. Three cases showed cytomegalic cells in liver sections by conventional staining, five showed hybridization with CMV DNA probes and seven showed reaction with the monoclonal antibody in the liver. CMV infection was detected not only in cytomegalic cells but also in many non‐cytomegalic cells by IHC and ISH, proving these techniques to be superior to routine histological examination. The inflammatory reaction in the liver was not prominent. The reason for the weak inflammatory response in the liver of our present cases, and the possible availability of IHC and ISH for analysis of liver biopsy and bronchoalveolar lavage specimens from immunocompromised hosts were discussed. Acta Pathol Jpn 41: 668–672, 1991.

Tsutsumi, Yutaka; Kawai, Kenji; Nagakura, Kouichi

doi: 10.1111/j.1440-1827.1991.tb02791.xpmid: 1776466

Using patients' sera diluted from 1: 10 to 1: 1,000 as the primary antibodies in indirect immunoperoxidase staining, the authors visualized a variety of infectious agents in formalin‐fixed, paraffin‐embedded tissue sections. The target lesions included 1) pyoderma caused by Staphylococcus aureus, 2) cryptococcal infection, 3) dermal sporotrichosis, 4) colon ulcer caused by amebic dysentery, 5) cutaneous leishmaniasis, and 6) chronic liver abscess containing ova of Ascaris lumbricoides. The infectious agents were clearly identified in the respective lesions. Paraffin sections of other kinds of infectious lesions served as controls to clarify the specificity of the immunostaining. While the sera of patients with bacterial and fungal infection showed a wide range of cros‐reactivity against bacteria and/or fungi, those with parasitic infection exhibited a relatively good specificity for the pathogen. Almost no immunoreactivity of endogenous human IgG in the paraffin sections was demonstrated under the conditions of this study. This approach can be used in diagnostic pathology, particularly when specific heteroantisera or monoclonal antibodies are unavailable. Acta Pathol Jpn 41 : 673–679, 1991.

Kihira, Takayuki; Shiraishi, Taizo; Yatani, Ryuichi; Roa, Ivan; Liu, Paul I.

doi: 10.1111/j.1440-1827.1991.tb02792.xpmid: 1776467

Renal cell carcinomas incidentally discovered at autopsy (IRCs) were retrospectively analyzed to determine whether they had any pathological features differing from clinical renal cell carcinomas (CRCs): From 7,970 autopsy cases, there were 51 cases (0.65%) of renal cell carcinoma (RC) including 42 men and 9 women (ratio 4.6:1). The mean age of RC cases was 66.3±12.9 (range of 20 to 91 years). Of the 51 RC cases, approximately half of them (25/51) were IRC cases. No difference was shown in age and sex between IRC and CRC cases. Mean tumor size of IRC was 2.6±2.5 cm in diameter. This was significantly smaller (P<0.01) than that of CRC (7.3±2.8 cm). Histologically, both grade 1 and clear cell type were significantly more predominant among IRC cases than CRC cases (P<0.01 and P<0.05, respectively). Only one out of 25 cases of IRC had distant metastasis, as compared to 23 out of 26 CRC cases (88.5%). These pathological features indicate that the incidentally discovered renal cell carcinoma may have less malignant potential than clinical tumors. Unexpectedly, the majority of the IRC cases (88.0%) were associated with advanced neoplasia of other sites, as compared to only 19.0% of CRC cases (P<0.01). Acta Pathol Jpn 41: 680–684, 1991.

Hisaoka, Masanori; Ohta, Hideki; Haratakel, Joji; Horie, Akio

doi: 10.1111/j.1440-1827.1991.tb02793.xpmid: N/A

A case of melanocytic schwannoma, a rare form of schwannian neoplasm, in the thoracolumbar spinal canal of a 52‐year‐old man is presented. Histopathologically, the tumor was composed of irregularly interlacing spindle‐shaped cells showing cystic degeneration, with occasional pigmented tumor cells. The tumor cells showed a low degree of nuclear pleomorphism without any mitotic figures. These histological features were considered to be consistent with a benign schwannian tumor showing pigmentation. Most of the pigments were considered to be melanin histochemically and immunohistochemically. According to the pathological features of the present tumor and those described previously in the literature, the neoplastic Schwann cells were assumed to have melanogenetic capacity, and the concept of the common neural crest origin of Schwann cells and melanocytes appeared to be demonstrated in the present tumor. Acta Pathol Jpn 41: 685–688, 1991.

Matsumoto, Toshiharu; Kuwabara, Noriyuki; Shiotsu, Hidetoshi; Fukuda, Yoshiro; Yanai, Akira; Ichikawa, Ginichiro

doi: 10.1111/j.1440-1827.1991.tb02794.xpmid: 1776469

Necrotizing sialometaplasia is a benign inflammatory process, which histologically can mimic squamous cell carcinoma. A 63‐year‐old man underwent left hemiglossectomy involving transplantation of a myocutaneous flap for squamous cell carcinoma of the tongue. One month after the operation, necrotizing sialometaplasia occurred in the minor salivary gland tissue of the mouth floor, compressed by the necrotic flap. This case is very unusual because of the ocurrence of necrotizing sialometaplasia in the floor of the mouth. The etiology of the lesion was considered to be ischemia secondary to compression by the necrotic myocutaneous flap. Acta Pathol Jpn 41: 689–693, 1991.

Yokose, Tomoyuki; Fukuda, Hiroshi; Ogiwara, Akira; Sakai, Kunihiko; Saitoh, Kiyoshi

doi: 10.1111/j.1440-1827.1991.tb02795.xpmid: 1776470

The authors report a case of myxoid leiomyosarcoma of the kidney accompanying ipsilateral ureteral transitional cell carcinoma. A 74‐year‐old male patient complained of turbid urine and macroscopic hematuria. He also complained of left back pain, appetite loss and weight loss. Computed tomography revealed a large mass in the left retroperitoneum. Urine cytology disclosed two types of malignant cells, atypical spindle‐shaped cells and transitional cell carcinoma. Left total nephro‐ureterectomy was performed. The left kidney was occupied by a 6X4X4 cm, multinodular and mucinous tumor. A transitional cell carcinoma of the left ureter was also observed. The renal tumor was composed of atypical spindle‐shaped cells in the mucinous stroma, which showed positive immunoreactivity for anti‐muscle‐specific actin and anti‐desmin antibodies. The ultrastructural examination revealed intracytoplasmic microfilaments with dense bodies, pinocytotic vesicles and junctional structure. These findings were suggestive of the myogenic feature of the case. Urine cytology revealed a number of sarcoma cells in this case since the sarcoma cells markedly invaded the renal pelvis and were apt to separate individually in myxoid stroma. Simultaneous and ipsilateral double malignancies of the renal sarcoma and ureteral transitional cell carcinoma have never been reported in the literature. Acta Pathol Jpn 41: 694–700, 1991.

Nomura, Kouichi; Furusato, Masakuni; Nikaido, Takashi; Aizawa, Shigeo

doi: 10.1111/j.1440-1827.1991.tb02796.xpmid: 1776471

A 23‐year‐old woman underwent resection of a tumorous right ovary after long‐standing irregular genital bleeding. The tumor measured 50X30 mm and had a yellowish‐white solid cut surface with scattered small cysts. The light microscopic diagnosis was a sex cord tumor with annular tubules. Ultrastructurally, the tumor cells had Charcot‐Boettcher filaments and showed vimentin positivity by immunohistochemistry. A three‐dimensional reconstruction study proved that the tumor cell nests had an ovoid outer margin and contained blind‐ended ellipsoid hyaline bodies. This tumor is presumed to be a variant of sex cord/stromal tumor showing differentiation predominantly to Sertoli cells. Acta Pathol Jpn 41: 701–706, 1991.