Yasumasa Monobe

Solid-pseudopapillary carcinoma of the pancreas

A case of solid‐pseudopapillary carcinoma (SPC) of the pancreas in a 34‐year‐old Japanese woman is presented. An abdominal ultrasonography revealed a mass, which measured 10 cm in diameter, in the body and tail of the pancreas. The tumor was resected and it was originally diagnosed as a non‐functioning islet cell tumor. One year and five months later, the patient was re‐admitted to hospital, and liver metastasis was confirmed by ultrasonography. The patient died 6 days after the second transcatheter arterial embolization (TAE) required for the metastasis. The autopsy showed small foci of liver metastasis. A retrospective examination of the tumor suggested the diagnosis of SPC because of its characteristic solid and pseudopapillary structures, immunohistochemical findings, and liver metastasis. This case suggests that capsular invasion, specifically found at the surgical margin of the peritoneal side, may be an important pathological finding that is suggestive of malignant potential in solid‐pseudopapillary tumor. If there is such a finding in a surgical specimen, an intensive follow up should be advised to the clinician.

Ectopic hamartomatous thymoma : Report of a case with fine needle aspiration biopsy findings

BACKGROUND Ectopic hamartomatous thymoma is a rare, benign tumor occurring exclusively in the supraclavicular and suprasternal regions. To the best of our knowledge, there are no English-language reports on its cytologic findings. CASE A fine needle aspiration specimen from a mass in the suprasternal region in a 63-year-old male revealed epithelial cell nests, spindle cells, a cluster of mature adipocytes and a small number of lymphocytes. CONCLUSION Although ectopic hamartomatous thymoma is very rare, fine needle aspiration cytology may contribute to the correct diagnosis in conjunction with the characteristic clinical findings.

An autopsy case of amebic meningoencephalitis. The first Japanese case caused by Balamuthia mandrillaris

We report here the first case of amebic meningoencephalitis caused by Balamuthia mandrillaris in a 78‐year‐old Japanese woman with Sjögrens syndrome. Fourteen days before her death, she presented with high fever and lost consciousness and later developed neck stiffness and abducens palsy. Computed tomography scans of the brain demonstrated multiple low‐density areas throughout the brain. Neuropathologically, hemorrhagic and necrotic lesions with many amebic trophozoites were scattered in the brain and spinal cord. Granulomatous lesions were only rarely found. The amebas were identified as Balamuthia mandrillaris based on immunofluorescence assay. Clinicopathologically, our case was thought to be an intermediate between primary amebic meningoencephalitis due to Negleria fowleri and granulomatous amebic encephalitis due to Acanthameba species. Essentially, the case was one of an elderly person with suspected immunodeficiency with fulminant necrotic meningoencephalitis and scanty granulomatous lesions of 14 days course.

Hepatoid adenocarcinoma of the gallbladder: Case report and review of the literature

A rare case of hepatoid adenocarcinoma (HAC) of the gallbladder occurred in a 72‐year‐old man who presented with abdominal pain and was admitted to hospital. Ultrasonography and computed tomography revealed a mass in the gallbladder, multiple nodules in the liver and enlargement of the lymph nodes. He was diagnosed as having a gallbladder carcinoma with multiple liver and lymph node metastases. Cholecystectomy and partial hepatectomy was performed. Histologically, most of the mass in the gallbladder was composed of cells with eosinophilic cyto‐plasm arranged in a trabecular pattern, which resembled hepatocellular carcinoma, but there was a component of well‐differentiated adenocarcinoma in the mucosa. Immunohistochemically these hepatoid tumor cells were positive for Hepatocyte (Hepatocyte Paraffin 1: Hep Par1), which is considered highly sensitive and highly specific for hepatocyte differentiation. Based on these findings, this case was diagnosed as hepatoid adenocarcinoma of the gallbladder, which is generally a vary rare neoplasm in the literature, but should be included in the differential diagnosis of a mass in the gallbladder.

Expression of sphingosine-1-phosphate receptor 1 in mantle cell lymphoma

The distribution and pathological significance of sphingosine-1-phosphate receptor 1 expression are still unclear. In this study, we evaluated sphingosine-1-phosphate receptor 1s suitability as a diagnostic marker for malignant lymphoma by immunostaining formalin-fixed paraffin-embedded sections using a well-defined commercial anti-sphingosine-1-phosphate receptor 1 antibody. Sphingosine-1-phosphate receptor 1 was strongly expressed on the surface of small lymphocytes forming primary lymphoid follicles and in the mantle zone of secondary lymphoid follicles. Microarray-based immunohistochemistry with tissue samples from 85 lymphoid malignancy cases demonstrated that sphingosine-1-phosphate receptor 1 was expressed on the surface of mantle cell lymphoma cells. Strong expression was observed in all classical mantle cell lymphoma cases involving the lymph node (19 out of 19), gastrointestinal tract (10 out of 10), bone marrow (9 out of 9), and orbita (1 out of 1). Good results were obtained even in sections where cyclin D1 signals were lost because of over-fixation and/or decalcification. One aggressive variant of mantle cell lymphoma displayed a weaker membranous staining than classical mantle cell lymphoma in the lymph node and bone marrow. In a cyclin D1-negative mantle cell lymphoma of the orbita, no conclusive result was obtained. No cases of follicular lymphoma, marginal zone lymphoma, B lymphoblastic leukemia/lymphoma, or Burkitts lymphoma showed any significant expression, whereas 2 out of 6 chronic lymphocytic leukemia/small lymphocytic lymphomas in bone marrow, 1 out of 3 lymphoplasmacytic lymphomas in the lymph node, and 2 out of 37 diffuse large B-cell lymphomas exhibited staining. A quantitative reverse transcription polymerase chain reaction-based analysis of mantle cell lymphoma lines revealed the sphingosine-1-phosphate receptor 1 mRNA expression level to be well correlated with the results of immunocytochemistry, flow cytometry, and western blotting. Thus, sphingosine-1-phosphate receptor 1 immunohistochemistry may be useful in the histological diagnosis of mantle cell lymphoma with formalin-fixed and paraffin-embedded sections. The antigen may be particularly valuable in cases where cyclin D1 immunostaining is not successful.

Endocervical-like mucinous borderline tumors of the ovary: Clinicopathological features and electron microscopic findings

Endocervical-like mucinous borderline tumor (EMBT) is a distinct entity of the ovary that seems to be underrecognized. It occurs with relatively high frequency in Japanese women. Compared with intestinal-type mucinous borderline tumor (IMBT), more frequent bilateral occurrence, paucilocular cysts, association with endometriosis, absence of pseudomyxoma but possible association of peritoneal implants and lymph node metastases, and lower mortality rate are the characteristic features. Histologically, it consists of a mixture of two types of epithelium, tall columnar mucinous cells and stratified eosinophilic cells. Electron microscopy revealed that they were endocervical glandlike mucinous cells and ciliated columnar epithelium reminiscent of the fallopian tube. As the mixture of EMBT and serous borderline tumor (seromucinous borderline tumor) occurs, these findings may show that the tumor shows MÜllerian origin with two-way differentiation, or differentiation toward endocervical glands with metaplastic features as seen in reactive endocervical lesions.

Methotrexate-Induced Lymphoproliferative Disease: Epstein-Barr Virus–Associated Lymphomatoid Granulomatosis

Case Report An asymptomatic 76-year-old woman presented with a lung mass on chest radiography. She had received methotrexate for 5.5 years (4 mg per week for 4 years and 8 mg per week for 1.5 years) for rheumatoid arthritis. Contrast-enhanced chest computed tomography revealed lung tumors with an angiogram sign in the right middle lobe (Fig 1A). An endobronchial image on flexible bronchoscopy demonstrated ulcerative erosion surrounded by pale mucosa in the right upper lobe orifice (Fig 1B; white arrowhead indicates the right upper bronchus). A biopsy of the lesions showed Epstein-Barr virus (EBV)–related lymphoproliferative disease (LPD), which was compatible with grade 2 lymphomatoid granulomatosis (LYG) according to the WHO classification on the basis of immunohistochemical findings. Serum EBV-viral capsid antigen immunoglobulin G index (12.9; normal, 0.5) and EBV nuclear antigen index (2.2; normal: 0.5) were elevated, whereasEBV-viralcapsidantigenimmunoglobulinMwasnegative.Realtime polymerase chain reaction for EBV DNA demonstrated 220 copies/mL (normal, 100 copies/mL). EBV hematoxylin and eosin staining showed the bronchus epithelium and subcutaneous infiltration of small lymphocytes, with necrosis (Fig 2A, 40 magnification; Fig 2B, 400 magnification). Figures 2C, 2D, 2E, and 2F show immunostaining using the CD20 antibody ( 40 magnification), CD79a antibody ( 40 magnification),latentmembraneprotein1antibody( 100magnification),and EBV-encoded small RNA–1 in situ hybridization ( 200 magnification), respectively. The positive results indicated EBV-induced B-cell transformation. Four weeks after discontinuation of methotrexate, chest radiography showed tumor shrinkage. Over the next 4 weeks, the disease improved remarkably (Figs 1C and 1D). The tumor has remained in this shrunken state for 1 year.

Poikilodermatous mycosis fungoides with a CD8+ CD56+ immunophenotype: a case report and literature review.

Mycosis fungoides (MF) represents the most common type of cutaneous lymphoma. MF shows varieties in both its clinical presentation and immunophenotype. We herein report one case of poikilodermatous MF with a CD8+ CD56+ immunophenotype and present a literature review. A 20‐year‐old Japanese woman presented with a 10‐year history of multiple poikilodermatous and reddish or brownish patches with mild pruritus on the chest, abdomen, back, buttock and thighs. Histopathologically, small‐ to medium‐sized atypical lymphocytes infiltrated into the epidermis, indicating epidermotropism, along the basal layer, and distributed in band‐like appearance in the papillary dermis. Immunohistochemically, atypical lymphocytes expressed CD3, CD8, CD56, T‐cell intracellular antigen (TIA)‐1, granzyme B and beta F1 but lacked expression of CD4, CD20, CD30 and Epstein‐Barr virus (EBV) latent membrane protein 1. An EBV‐encoded small non‐polyadenylated RNA‐1 (EBER‐1) signal was not detected. On the basis of these findings, the diagnosis of CD8+ CD56+ MF was established. Poikilodermatous MF with a CD8+ CD56+ immunophenotype, as presented herein, is extremely rare. Although further investigation is needed to fully clarify the nature of this aberrant phenotype of MF, we stress that it is important to recognize this rare immunophenotype of MF to distinguish it from aggressive cytotoxic cutaneous lymphomas.

Papillary squamous cell carcinoma of the uterine cervix: diagnostic pitfalls

A case of papillary squamous cell carcinoma (PSCC) of the uterine cervix is reported. The patient was a 73‐year‐old Japanese woman with acute renal failure and bilateral hydronephrosis. A cauliflower‐like mass was found in the uterine cervix. A uterine cervical biopsy specimen revealed PSCC in situ, while clinically it was an invasive carcinoma. Uterine cervical biopsy was performed a second time to confirm its stromal invasion. However, only small fragments were obtained because of heavy bleeding from the tumor and they showed PSCC in situ again. Following this, computed tomography of the pelvis revealed a 5 cm mass in the uterine cervix, invading the vagina and urinary bladder. Though deep‐wedge biopsy, loop electrosurgical excision, or cone biopsy is recommended to evaluate PSCC, it may be impossible to perform any of these procedures because of bleeding such as that seen in our case. In these circumstances, good communication between pathologists and clinicians is important since lack of communication may cause PSCC to be microscopically misinterpreted as in situ carcinoma rather than invasive carcinoma.

Gastrointestinal stromal tumor with skeinoid fibers of the ileum

Gastrointestinal stromal tumor (GIST) is not uncommon among gastrointestinal nonepithelial tumors, but there are few reports describing the cytologic findings. We report a case of GIST with skeinoid fibers in scrape cytology preparation. The patient was a 53‐year‐old man with a tumor in the small intestine. Scrape preparations from the cut surface of the resected tumor revealed cellular material composed of spindle cells showing loose clusters or single cells. The nuclei were spindled, elongated or cigar‐shaped, and relatively uniform. The cytoplasm was fragile and demonstrated a finely fibrillar material. Dense hyaline materials with irregular outline were observed within the loose clusters composed of the tumor cells. The hyaline materials were also observed in the background. Histologic preparation showed spindle cells arranged in a fascicular or storiform pattern. Most eosinophilic globules were distributed between the tumor cells. The globules were positive in periodic acid‐Schiff reaction, and were stained blue with Massons trichrome stain. Immunohistochemically, the tumor cells were strongly and diffusely positive for c‐kit, focally and weakly positive for α‐smooth muscle actin, and negative for CD34 and S‐100 protein. We emphasize that skeinoid fibers are characteristic of GIST arising in the small intestine, and their presence predicts a good prognosis, even in malignant GIST. Diagn. Cytopathol. 2000;23:266–268.