A case of bone metastasis of hepatocellular carcinoma: Mallory hyaline bodies can lead to the correct cytological diagnosis.

Hepatocellular carcinoma (HCC) accounts for most primary tumors of the liver. Although bone metastasis does not occur in a high percentage of patients, bone metastasis is often found first, which leads to the diagnosis of HCC. In this report, we describe a case of bone metastasis from HCC in which bone lesions were detected incidentally, and in which a cytological diagnosis was difficult to make. The patient was a 78-year-old man with a history of renal dysfunction after orthopedic surgery. He underwent a thorough examination after a bone tumor was incidentally found on abdominal CT. Plasmacytoma was suspected. Fine needle aspiration cytology revealed irregular clusters of medium-to-large atypical epithelioid polygonal cells with relatively abundant eosinophilic, somewhat granular cytoplasm, and indistinct cell borders, which led to a diagnosis of malignancy. Histologically and immunohistochemically, the tumor was diagnosed as bone metastasis of HCC. Re-examination of the cytological specimen revealed characteristic Mallory hyaline bodies (MHBs). Immunohistochemistry using a cell transfer method revealed that they were positive for low molecular weight cytokeratin, Cam5.2, in a densely granular fashion. In this case, the cytological diagnosis of HCC was difficult to make due to the unclear cytoplasmic borders and absence of bile pigment. However, the identification of MHBs can potentially guide me to the correct cytological diagnosis.

A surgical case of high-grade urothelial carcinoma of the renal pelvis complicated with giant hydronephrosis, giving rise to diagnostic difficulties on a cytological examination.

BACKGROUND: We report a surgical case of urothelial carcinoma of the renal pelvis, resulting in diagnostic difficulties on cytological examination. CASE PRESENTATION: A man in his late 70s underwent nephrectomy for giant hydronephrosis and renal cysts after nephrostomy and renal cyst puncture and drainage. On all cytological examinations performed before surgery, including nephrostomy urine, renal cyst fluid, catheterized bladder urine, and bladder washings, we were unable to make any conclusive diagnosis of malignancy. The pathological diagnosis of the surgical specimen concluded that this was a case of high-grade urothelial carcinoma of the renal pelvis with focal squamous differentiation (pT4). Liver and lung metastases were identified 3 months after surgery, and the patient died 2 months later. CONCLUSION: It was very difficult to make a conclusive diagnosis using cytological specimens because of the presence of a small number of atypical cells with severe degenerative changes. Since clinicians cannot predict the potential for malignancy on preoperative imaging findings, it is critical to consider the difficulties in clinically making a correct diagnosis of urothelial carcinoma of the upper urinary tract, especially in cases complicated with giant hydronephrosis.

The potential usefulness of sputum cytology in the conclusive diagnosis of methotrexate-associated lymphoproliferative disorders: A case report.

BACKGROUND: Methotrexate has been used as an anchor drug for the treatment of rheumatoid arthritis and is considered to be a cause of methotrexate-associated lymphoproliferative disorder. Spontaneous regression can occur after withdrawal of methotrexate and may be associated with Epstein-Barr virus positivity and non-diffuse large B cell lymphoma histological type. Methotrexate-associated lymphoproliferative disorders are often diagnosed pathologically by lung biopsy. To the best of our knowledge, there have been no studies on the cytological diagnosis of methotrexate-associated lymphoproliferative disorder using sputum smears. CASE: A 70-year-old man, who was diagnosed with rheumatoid arthritis 13 years previously and who had been treated with methotrexate, presented shortness of breath and productive cough. Methotrexate-associated lymphoproliferative disorder was suspected as the sputum cytology showed many atypical lymphoid cells with hyperchromatic enlarged nuclei, foamy cytoplasm and distinct nucleoli. Chest computed tomography revealed multiple nodular shadows with interstitial pneumonia in the bilateral lower lung field. A lung biopsy specimen contained atypical lymphoid cells that were immunohistochemically positive for CD20 and MUM-1, and weakly positive for bcl-6, but negative for CD3 and CD10. There were no Epstein-Barr virus-infectious lymphoid cells by ISH-EBER. He was finally diagnosed with methotrexate-associated lymphoproliferative disorder (non-germinal center B-cell-like diffuse large B cell lymphoma histological type). Most of the nodules disappeared spontaneously following the withdrawal of methotrexate. DISCUSSION AND CONCLUSION: A cytologically conclusive diagnosis of methotrexate-associated lymphoproliferative disorder may be reached using sputum smears and clinical information.

Adenosquamous carcinoma of the uterine cervix displaying tumor-associated tissue eosinophilia.

BACKGROUND: Tumor-associated tissue eosinophilia is defined as an inflammatory response with the marked infiltration of eosinophils within tumor tissues. Tumor-associated tissue eosinophilia has been reported in various organs; however, no studies have examined the detailed cytopathological findings of tumor-associated tissue eosinophilia. CASE PRESENTATION: A 49-year-old woman presented with lower abdominal and back pain that had started 1 month earlier. A cervical biopsy revealed a diagnosis of non-keratinizing squamous cell carcinoma. A mildly increased number of eosinophils was observed in both cervical cytology and a biopsy. On pelvic computed tomography, a tumor mass measuring up to 5.5 cm in the largest diameter was seen in the uterine cervix. After 1 month, endometrial cytology was performed, and non-keratinizing squamous cell carcinoma together with normal endometrial glands was obtained in a background of marked eosinophil numbers. Tumor cells in an irregular-shaped solid nest had variable-sized hyperchromatic nuclei and light-green-stained cytoplasm. The number of eosinophils was obviously increased. Considering the possibility of tumor-associated tissue eosinophilia, we evaluated a peripheral blood sample and confirmed an increased number of eosinophils. Radical hysterectomy was performed, and the final pathological diagnosis was adenosquamous carcinoma. Although the number of eosinophils decreased after surgery, it increased again at the time of recurrence 1 year later. Chemo-irradiation was performed, but the patient died 1 year and 8 months after the operation. CONCLUSION: Cytopathologists should consider the presence of tumor-associated tissue eosinophilia by focusing on not only tumor cells but also the markedly eosinophilic background. The eosinophil count might be a useful marker of the disease activity.

A case report of infantile cystic nephroblastoma.

BACKGROUND: Nephroblastoma (NB) is a malignant embryonal neoplasm derived from nephrogenic blastemal cells. NB usually forms a solid mass, but in extremely rare cases, it may show cystic changes. CASE PRESENTATION: A six-month-old girl with persistent high fevers was found to have pyuria and bacteriuria. Ultrasonography revealed multilocular cysts in the right kidney. Right nephrectomy was performed with cyst wall rupture during surgery. An intraoperative rapid diagnosis, based on peritoneal fluid cytology, confirmed three components of blastemal, stromal, and epithelial cells. The blastemal cells were dyshesive, with scant to no cytoplasm and were the predominant cell type. The spindle-shaped stromal cells were arranged in fascicles. The epithelial cells demonstrated tubular structures. Macroscopically, the resected cystic tumor measured 80 mm in maximum diameter with a prominently thin cyst wall, but solid areas were also apparent. Histologically, the tumor was diagnosed as cystic NB (blastemal-predominant) displaying a triphasic pattern. Hyperchromatic nuclei and apoptotic bodies were found. The clinical stage classification of Japan Wilms Tumor Study group was 3. The patient was treated with chemotherapy and radiotherapy. Tumor recurrence and metastasis have not been observed in the 8 months since surgery. CONCLUSION: This is an extremely rare case of infantile cystic NB. We diagnosed the NB cells that appeared in the peritoneal fluid by intraoperative rapid cytology. Cytological examination proved to be a very useful technique for determining the clinical stage of NB. Additionally, we propose that massive tumor degeneration and necrosis be considered as a pathogenic mechanism of cyst formation in NB.

Cytopathological findings of proliferating pilomatricoma misdiagnosed as a malignant parotid gland tumor.

BACKGROUND: Pilomatricoma is a relatively common benign cutaneous adnexal neoplasm with differentiation towards the hair matrix, inner sheath of hair follicle and hair cortex. Proliferating pilomatricoma is a rare variant of pilomatricoma that can rapidly increase and may be misidentified as a malignant tumor. We herein report the cytopathological findings of proliferating pilomatricoma misdiagnosed as a malignant parotid tumor. CASE PRESENTATION: A 64-year-old man noticed an acne-like nodule in the left parotid region. It was painless, but it increased to a maximum diameter of 4.5 cm over 2 years. Clinically, left parotid gland carcinoma was suspected, and fine-needle aspiration cytology was performed. Clusters of epithelial cells were observed in a necrotic background, and malignant epithelial cells derived from salivary glands were suspected. Histologically, the resected tumor was diagnosed as proliferating pilomatricoma composed of basophilic cells and shadow cells apart from the parotid gland. However, on a re-evaluation of the cytological specimens, the irregular-shaped epithelial cells were considered to be from basophilic cells. Shadow cells with nuclear disappearance were also confirmed. Tumor recurrence and metastasis have not been observed in the four years since surgery. CONCLUSION: The present case was first interpreted as a malignant parotid gland tumor, but it was actually a benign skin appendage tumor. Pilomatricoma sometimes rapidly increases and may be mistaken for a malignant tumor. Although it is critical to recognize not only basophilic cells but also shadow cells, it cannot be diagnosed by cytological findings. The final diagnosis should be made on excision specimen only.

Expression of coxsackie and adenovirus receptor reduces the lung metastatic potential of murine tumor cells.

The coxsackie and adenovirus receptor (CAR) is involved in the epithelial cell tight junction, the downregulated expression of which is observed in different cancer types. In the present study, we examined CAR's role in tumor metastasis using a B16 melanoma and CT26 colon adenocarcinoma model of experimental metastasis. In lung metastasis, the colony number of B16 cells stably expressing CAR (B16CAR) was significantly lower than that of the control CAR-negative B16 cells. B16 and CT26 cells transiently expressing CAR, which were transduced with adenovirus (Ad) vector expressing CAR, also reduced lung metastasis, suggesting that CAR plays a role in the early stage of metastasis. CAR expression significantly decreased the accumulation of B16 cells in the lung after i.v. injection and the migration in vitro. CAR expression reduced expression of alpha(v), alpha(4), beta(3) and beta(1) integrin, which play important roles in attachment to cells or basement membrane. Thus, CAR expression likely acts as a metastatic suppressor.

Efficient gene transfer into murine pancreatic islets using adenovirus vectors.

We investigated the efficiency of gene transduction into murine pancreatic islets using the adenovirus (Ad) vector. Western blotting analysis showed that mouse pancreatic islets express coxsackievirus and adenovirus receptor, a receptor for Ad. Nevertheless, gene expression after transduction of the Ad vector in vitro was observed only in the periphery of the islets, probably due to physical obstruction against Ad infection of the cells in the inside of islets. Ca(2+)-free treatment before the Ad vector transduction enhanced transduction efficiency in the islets, but not the cells in the inside of islets. The Ad vector transduction through the celiac artery in vivo and then cultivation of islets in vitro resulted in efficient transduction even in the inside of islets. Thus we propose a new strategy for efficient gene transfer to pancreatic beta-cells.

A new ether bond-splitting enzyme found in Gram-positive polyethylene glycol 6000-utilizing bacterium, Pseudonocardia sp. strain K1.

Pseudonocardia sp. strain K1 is the only Gram-positive bacterium among the bacteria aerobically metabolizing polyethylene glycol (PEG). Generally, PEG is metabolized by an oxidative pathway in which a terminal alcohol group of PEG is oxidized to aldehyde and to carboxylic acid and then an ether bond is oxidatively cleaved. As the cell-free extract of Pseudonocardia sp. strain K1 has PEG dehydrogenase, PEG aldehyde dehydrogenase and diglycolic acid (DGA) dehydrogenase (DGADH) activities, all of which are constitutively formed, the strain has a metabolic pathway similar to that so far known. We purified an ether bond-splitting enzyme as DGADH. The molecular mass of the enzyme was estimated to be 55 kDa; and it consisted of two identical subunits. The enzyme oxidatively cleaved both an ether bond of PEG 3000 dicarboxylic acid and DGA. The N-terminal amino acid sequence of the purified enzyme had high homology with various superoxide dismutases and the enzyme had also superoxide dismutase activity. The atomic absorption spectrum showed that approximately one atom of Fe was included in each subunit of the enzyme. DGADH activity increased in the cells grown in a PEG medium supplemented with FeCl(3). Thus, we concluded that the enzyme purified from Pseudonocardia sp. strain K1 is a new ether bond-splitting enzyme.

Cloning and expression of an ether-bond-cleaving enzyme involved in the metabolism of polyethylene glycol.

A gene encoding an ether-bond-cleaving enzyme, diglycolic acid dehydrogenase (DGADH) from polyethylene glycol-utilizing Pseudonocardia sp. strain K1, was cloned and expressed in Escherichia coli. The deduced amino acid sequence had a high homology with superoxide dismutases (SODs) from various bacteria. The recombinant protein showed the same activities as those of DGADH from Pseudonocardia sp. strain K1, namely, SOD activity and ether-bond-cleaving activity.