Primary retroperitoneal mucinous cystadenocarcinoma in a male patient.

Primary retroperitoneal mucinous cystadenocarcinomas (PRMCs) are rare. This is the first reported case in the literature in English of PRMC in a man. The 64-year-old man presented with a large retroperitoneal cystic tumour measuring 24 x 20 x 16 cm3, which was removed intact. Areas ranging from a benign mucinous cyst to borderline mucinous tumour to mucinous cystadenocarcinoma were observed on microscopy. Strong patchy staining for cytokeratins 7 and 20 and strong diffuse staining for MUC2 and MUC5AC core peptides, similar to staining patterns in ovarian mucinous tumours, were shown in the benign and atypical epithelium. Staining for CA19.9 and carcinoembryonic antigen was also shown by both components. The theory of its origin from the mucinous metaplasia of peritoneal (mesothelial) inclusion cysts, rather than from ectopic ovarian tissue or ovarian teratomas, is supported by the occurrence of such a tumour in a male patient.

An unusual cause of granulomatous inflammation: eosinophilic abscess in Langerhans cell histiocytosis.

Eosinophilic abscess inciting a granulomatous response has rarely been reported and appears not to have been described in the setting of a neoplasm. In this report, a case is described where a granulomatous response occurred around eosinophilic abscesses in a patient with Langerhans cell histiocytosis, an association which has not previously been documented. On histology, the excised lymph node showed the presence of eosinophilic abscess and necrosis surrounded by granulomas, which in turn were surrounded by Langerhans cells, a feature confirmed on immunohistochemistry. Although rare, this case highlights the importance of careful examination of eosinophilic abscess with granulomatous inflammation in order to exclude an underlying neoplasm.

Pathologic, radiologic and PET scan response of gastrointestinal stromal tumors after neoadjuvant treatment with imatinib mesylate.

AIM: The aim of this study is to review the radiologic, PET scan and pathologic response and the outcome of patients with advanced GIST treated with neoadjuvant IM followed by surgical resection. MATERIALS AND METHODS: We report a case and review 36 patients reported in MEDLINE with advanced GIST treated with neoadjuvant IM followed by surgical resection. RESULTS: Thirty-seven patients with a median age of 56 years (range, 32-76 years) at presentation were treated with neoadjuvant IM. Radiologic response accurately predicted pathological response in 31/36 patients, whereas PET scan was accurate in predicting treatment response in only 6/23 patients. CONCLUSION: This study demonstrates that the pathologic response of GIST to IM is usually incomplete and does not correlate with the complete response seen on PET scan. This finding suggests that surgical resection will continue to play a vital role in the treatment of patients with advanced disease responding to IM treatment.

Incidental hypoglobus: primary amyloidosis of the superior rectus.

A 69-year-old man who presented with incidental hypoglobus was found to have an isolated superior rectus mass. Diagnosis of primary amyloidosis of superior rectus was made on incisional biopsy and negative systemic work-up. This is an unusual manifestation and site for amyloidosis and should be a differential of any extraocular muscle mass.

Pathological diagnosis of columnar cell lesions of the breast: are there issues of reproducibility?

AIMS: To assess inter/intraobserver variability in the interpretation of a series of digitised images of columnar cell lesions (CCLs) of the breast. METHODS: After a tutorial on breast CCL, 39 images were presented to seven staff pathologists, who were instructed to categorize the lesions as follows: 0, no columnar cell change (CCC) or ductal carcinoma in situ (DCIS); 1, CCC; 2, columnar cell hyperplasia; 3, CCC with architectural atypia; 4, CCC with cytological atypia; 5, DCIS. Concordance with the tutor's diagnosis and degree of agreement among pathologists for each image were determined. The same set of images was re-presented to the pathologists one week later, their diagnoses collated, and inter/intraobservor reproducibility and level of agreement for individual images analysed. RESULTS: Diagnostic reproducibility with the tutor ranged from moderate to substantial (kappa values, 0.439-0.697) in the first exercise. At repeat evaluation, intraobserver agreement was fair to perfect (kappa values, 0.271-0.832), whereas concordance with the tutor varied from fair to substantial (kappa values, 0.334-0.669). There was unanimous agreement on more images during the second exercise, mainly because of agreement on the diagnosis of DCIS. The lowest agreement was seen for CCC with cytological atypia. CONCLUSIONS: Interobserver and intraobserver agreement is good for DCIS, but more effort is needed to improve diagnostic consistency in the category of CCC with cytological atypia. Continued awareness and study of these lesions are necessary to enhance recognition and understanding.

Clinical usefulness of endoscopic ultrasonography with or without fine needle aspiration in the diagnosis and staging of pancreatic carcinoma.

INTRODUCTION: The aims of this study was to show the accuracy and clinical usefulness of endoscopic ultrasonography (EUS) with EUS-guided fine needle aspiration (FNA) in the diagnosis and staging of pancreatic cancer not obvious in computed tomographic (CT) scan abdomen imaging. MATERIALS AND METHODS: Five male patients were evaluated; 4 presented with obstructive jaundice and 1 had unexplained loss of weight. The mean age was 66 years (range, 40 to 77). All had CT scan abdomen imaging which did not show any obvious pancreatic tumour. EUS with FNA was done for all cases when indicated. Surgical findings, if any, were obtained and compared to EUS findings. RESULTS: EUS easily detected the pancreatic tumour in all 5 cases. The tumour sizes detected ranged from 27 to 40 mm in diameter. These corresponded fairly accurately with that of surgical findings for all 3 who had surgery. EUS reported 3 cases with pathological lymph node involvement. All 5 cases were confirmed by FNA or surgery. EUS was also accurate in 4 cases, which reported the absence of portal vein or superior mesenteric vein invasion. Surgical documentation could not verify the fifth case. There were no complications at all from the EUS with/without FNA. CONCLUSION: This case series showed that EUS with/without FNA appears to be useful and safe in diagnosing and staging pancreatic head tumours not detectable by CT scanning.

Infiltrating lymphocytes in undifferentiated nasopharyngeal cancer lack metallothionein expression.

Metallothionein (MT) is a metal-binding protein with functional roles in cell growth, repair and differentiation. MT is reported to be differentially expressed in lymphocytes of malignant gastrointestinal lesions. The level of MT protein was examined by immunohistochemical analysis at light microscopic and ultrastructural level in infiltrating lymphocytes from 20 cases of undifferentiated nasopharyngeal carcinoma (NPC). MT expression was found to be absent in the infiltrating lymphocytes of NPC and in reactive lymphocytes of lymphoid hyperplasia in nasopharyngeal tissues. Ultrastructural examination confirmed the absence of MT immunoreactivity in the lymphoid infiltrate of NPC. On the other hand, malignant lymphoblasts of diffuse large cell lymphoma, showed MT-immunopositivity by immunoelectron microscopy. This study demonstrates a lack of MT expression in the lymphoid stroma of undifferentiated NPC, a further characteristic of its non-neoplastic nature.

Metabolic consequences of phosphotransferase (PTS) mutation in a phenylalanine-producing recombinant Escherichia coli.

E. coli strain PPA305, which has a wild-type PTS system, and PPA316, which utilizes a proton-galactose symport system for glucose uptake, were used as host strains to harbor a phenylalanine overproduction plasmid pSY130-14 and to study the effects of using different glucose uptake systems on phenylalanine production. The non-PTS strain (PPA316/pSY130-14) produced much less phenylalanine, ranging from 0 to 67% of that produced by the PTS strain (PPA305/pSY130-14) depending on cultivation conditions used. The non-PTS strain PPA316/pSY130-14 had an intracellular PEP concentration only one-sixth that of the PTS strain, PPA305/pSY130-14. Additionally, PPA316/pSY130-14 had a substantially lower energy state in terms of the size of the pool of high-energy phosphate compounds and the magnitude of the pH difference across the cytoplasmic membrane. The non-PTS strain consumed oxygen at a higher rate, attained lower biomass concentration, and produced no acetate and phenylalanine during fermentation, suggesting more carbon was oxidized to CO2, most likely through the TCA cycle. Analysis of intracellular fluxes through the central carbon pathways was performed for each strain utilizing exponential phase data on extracellular components and assuming quasi-steady state for intermediate metabolites. The non-PTS strain had a higher flux through pyruvate kinase (PYK) and TCA cycle which, in agreement with the observed higher oxygen uptake rate, suggests that more carbon was oxidized to CO2 through the TCA cycle. Further analysis using rate expression data for PYK and NMR data for the intracellular metabolites identified the regulatory properties of PYK as the probable cause for lower intracellular PEP levels in PPA316/pSY130-14.

Lymphocytic infiltration in undifferentiated nasopharyngeal cancer.

BACKGROUND: Undifferentiated nasopharyngeal carcinoma (NPC) is characterized by prominent lymphocytic infiltration. Although the lymphoid infiltrate in NPC has been examined extensively in morphologic and immunocytochemical studies, the significance of this lymphoid infiltrate and its correlation with prognosis has been a subject of controversy for years. OBJECTIVE: To elucidate the significance of lymphoid infiltration in undifferentiated NPC. DESIGN: Evaluation of the relationship between lymphocytic infiltration in NPC and cervical lymph node status, ultrastructural examination of the lymphoid infiltrate, and assessment of lymphocytic infiltration as an independent prognosticator of regional node metastasis. MATERIALS AND METHODS: Lymphocytic infiltration was evaluated quantitatively in 20 cases of undifferentiated NPC using light microscopy. Four cases of undifferentiated NPC were processed for conventional electron microscopy. The effects of degree of lymphocytic infiltration, age, and tumor stage on cervical nodal metastasis were analysed using the logistic regression model. RESULTS: The degree of lymphoid infiltration correlated with cervical nodal metastasis (P<.001). Ultrastructural evidence of lymphocytes destroying cancer cells was seen. Lymphocytic infiltration was found to be an independent factor affecting cervical nodal metastasis (P =.02, univariate analysis; P =.03, multivariate analysis). CONCLUSIONS: The lymphoid infiltrate is beneficial in undifferentiated NPC, and its presence may deter regional metastasis of cancer cells to the cervical nodes.

An unusual case of nonspecific interstitial pneumonia treated initially with surgical resection.

Nonspecific interstitial pneumonia (NSIP) has been recently described as a distinct clinicopathologic entity. We describe an unusual case of a middle-aged man who presented with exertional dyspnoea, cough, radiographic airspace opacities in the left lung and previous history of right thoracotomy for suspected right lower lobe neoplasm. Histology at that time revealed "chronic inflammation". A course of high-dose steroids was given after failure of the airspace opacities to respond to a trial of antituberculous therapy. Improvement in symptoms and radiological appearance was noted subsequently. A diagnosis of nonspecific interstitial pneumonia was made on review of the initial open lung biopsy specimen. Seven months after tailing down to maintenance low-dose steroids, the NSIP relapsed. The NSIP subsequently responded again to high-dose steroids. This case illustrates that NSIP is a difficult diagnosis, may present as a focal lung opacity initially, and may relapse after steroid dose is tailed down.

Ectopic Cushing's syndrome in a young female with atypical [corrected] bronchial carcinoid tumour.

A 17-year-old female with a large mass in the left thorax presenting with ectopic Cushing's syndrome is described. Biochemical evaluation revealed a corticotropin(ACTH)-dependent hypercortisol state. Surgical resection of the tumour resulted in clinical remission and correction of hypercortisolism and normal plasma ACTH levels. The histology was that of an atypical carcinoid. Bronchial carcinoid tumour is an extremely uncommon but well recognised cause of ectopic Cushing's syndrome. These patients may pose diagnostic dilemma in distinguishing form those with Cushing's disease because of the similarity in the clinical, biochemical and radiologic findings.

Malignancy arising in seborrheic keratosis: a report of two cases.

We describe the pathological features of two cases of malignant transformation occurring in seborrheic keratosis. The lesions affected elderly individuals: a 79-year-old Chinese lady and a 79-year-old Chinese gentleman, both of whom had long-standing seborrheic keratoses with recent increase in size. Histologically, the malignancies identified were invasive well-differentiated squamous cell carcinoma and Bowen's disease (squamous carcinoma in situ), respectively. Pre-existing seborrheic keratoses demonstrating a zone of transition into the malignant foci were present. Aetiologic factors that have been proposed to explain these exceedingly rare occurrences have included prolonged sun damage and chronic low dose radiation exposure.

Primary amyloidosis of the bladder: a case report.

An otherwise healthy elderly lady who presented with gross haematuria was found to have a papillary lesion in her bladder. Histological examination of the lesion showed amyloid deposits. Investigations for systemic amyloidosis were all negative. Primary amyloidosis of the bladder is a rare clinicopathological condition with only 57 documented cases in the medical literature. It often mimics bladder carcinoma in presentation and cystoscopic appearance. Amyloid deposits in the bladder may be primary (organ-limited amyloidosis) or part of systemic amyloidosis. Exclusion of systemic amyloidosis is important for management and prognosis. Localised primary lesions are best treated with transurethral resection and recurrences are uncommon. Diffuse involvement of the bladder is difficult to manage and may require urinary diversion. We report the first case of primary amyloidosis of the bladder in Singapore.

A case report of Aspergillus hypersensitivity syndrome with obstructing bronchial aspergillosis.

INTRODUCTION: A 62-year-old Indian male with diabetes mellitus presented with atypical, overlap features of Aspergillus hypersensitivity syndrome and obstructing bronchial aspergillosis. CLINICAL PICTURE: He was febrile and tachypnoeic with diffuse crepitations and wheezing. Chest X-ray was normal but eosinophil count was 2900/mm3 and Ig E > 10,000 IU/ml. TREATMENT AND OUTCOME: He responded initially to high dose steroid therapy but deteriorated subsequently from extensive mucus plugging of the bronchial tree which resulted in respiratory failure and death. He was HIV-negative. CONCLUSION: Culture and histologic examination of bronchoscopically identified tracheobronchial mucus plugs should be performed as early treatment may be life-saving.

Primary hyperparathyroidism: a case with severe skeletal manifestations.

Over the years, patients with primary hyperparathyroidism are often asymptomatic and diagnosis is suspected on the incidental finding of hypercalcaemia. We report a patient, a middle-aged man from northern Sumatra, with a florid but uncommon presentation of severe bone pains and bilateral femoral neck fractures. He was found to have a solitary parathyroid adenoma which was successfully removed surgically. Postoperatively, the patient had severe symptomatic hypocalcaemia that required aggressive replacement therapy with calcium, magnesium and active vitamin D. He was well clinically and had significant improvement of biochemical indices on follow-up at 3 months. This report is followed by a review on the management of this condition.

Hypoglycaemia from islet cell hyperplasia and nesidioblastosis in a patient with type 2 diabetes mellitus--a case report.

INTRODUCTION: We report the first case of hypoglycaemia from beta cell hyperplasia with nesidioblastosis in an Asian adult with pre-existing type 2 diabetes. CLINICAL PICTURE: A 57-year-old Chinese woman presented with hyperinsulinaemic hypoglycaemia despite discontinuation of oral hypoglycaemic agents 4 months after diagnosis of type 2 diabetes. Preoperative portal venous sampling suggested regionalisation to the neck of the pancreas. Intraoperative ultrasound and palpation of the fully mobilised pancreas were non-localising. TREATMENT: A subtotal 85% pancreatectomy was performed with success. OUTCOME: Histology showed no evidence of tumour, but revealed islet hyperplasia and nesidioblastosis. Her diabetes was subsequently well controlled on metformin therapy. CONCLUSION: Endogenous hyperinsulinism from beta cell hyperplasia with nesidioblastosis may rarely occur in type 2 diabetics. However, this remains a diagnosis of exclusion that is confirmed only on surgical pathology. In affected individuals, preoperative portal venous sampling may be falsely localising, especially if selective sampling of the smaller peri-pancreatic veins is omitted. Definite treatment involves pancreatectomy, although the extent of surgical resection is not well established.

Inflammatory myofibroblastic tumour of the duodenum.

Inflammatory myofibroblastic tumours (IMTs) of the duodenum and head of the pancreas are rare. They are of probable immunological aetiology and preoperatively indistinguishable from adenocarcinomas of the pancreatic head. We describe a patient with duodenal IMT and gastric outlet obstruction, and present a review of pancreatic head and duodenal IMTs in the literature. IMTs of the pancreatic head present as obstructive jaundice, while those of the duodenum present as gastric outlet obstruction. Surgery is the primary modality of treatment. Adjuvant chemotherapy and radiotherapy are controversial and reserved for incomplete resections and IMTs of a pathologically aggressive nature. Otherwise, recurrence is uncommon and surgery curative.

Malignant perivascular epithelioid cell tumour of the fibula: a report and a short review of bone perivascular epithelioid cell tumour.

Perivascular epithelioid cell tumour (PEComa) is a term applied to a family of mesenchymal tumours composed of varying proportions of spindle and epithelioid cell components associated with HMB-45 expression. PEComa rarely arises in the soft tissue, visceral organs, skin and bone. This report details an instance when a purely epithelioid PEComa arose from the right fibula of a 52-year-old Chinese woman without features of tuberous sclerosis complex. The excision specimen disclosed an epithelioid tumour with a nested pattern associated with areas of nuclear pleomorphism, mitotic activity, necrosis and vascular invasion in addition to HMB-45 expression on immunohistochemistry. To the best of the authors' knowledge, this represents the first case of a histologically malignant PEComa of the bone. A short review of primary bone PEComas and potential problems in diagnosis is presented.

Prospective evaluation of transient elastography for the diagnosis of hepatic fibrosis in Asians: comparison with liver biopsy and aspartate transaminase platelet ratio index.

BACKGROUND: Transient elastography (TE) is a reliable non-invasive predictor of hepatic fibrosis, but data on TE in Asians are limited. AIM: To evaluate prospectively the accuracy of TE for diagnosis of hepatic fibrosis in Asians compared with APRI (aspartate transaminase to platelet ratio index). METHODS: One hundred and twenty consecutive patients who underwent liver biopsy were enrolled. TE (Fibroscan) was performed by two independent operators. Fibrosis was graded by two independent pathologists using the METAVIR classification. Area under receiver operating curves (AUROC) were used to evaluate the accuracy of TE and APRI in diagnosing significant fibrosis (F >or= 2) and cirrhosis (F4). RESULTS: Predominant aetiologies were hepatitis B (48%), non-alcoholic steatohepatitis (14%) and hepatitis C (8%). TE was unsuccessful in five patients (4.2%) because of small inter-costal space (three patients), obesity and ascites. There was good correlation between TE and fibrosis (r = 0.606). AUROC for diagnosis of significant fibrosis was 0.856 (95% CI 0.779-0.932) for TE and 0.673 (95% CI 0.568-0.777) for APRI. AUROC for diagnosis of cirrhosis was 0.924 (95% CI 0.857-0.990) for TE and 0.626 (95% CI 0.437-0.815) for APRI. Optimal TE value was 9.0 kPa for diagnosis of significant fibrosis and 16.0 kPa for cirrhosis with specificity/sensitivity/PPV/NPV/accuracy of 82.6%/85.2%/80.9%/86.7%/84.1% and 88.9%/82.7%/32.0%/98.8%/83.2%, respectively. CONCLUSIONS: Transient elastography is a reliable predictor of hepatic fibrosis in Asians. Failure of TE in Asians is commonly because of small inter-costal space. TE is superior to APRI for non-invasive diagnosis of hepatic fibrosis and cirrhosis.

Histological subtypes of symptomatic central nervous system tumours in Singapore.

The objective was to identify the different subtypes of symptomatic CNS tumours that are encountered in Singapore. Our hospital pathology and operative records from 1994 to 1998 were reviewed and information regarding all patients who underwent biopsy or resection as part of their diagnostic and therapeutic evaluation was extracted. Only histologically confirmed tumours were included in this analysis. Meningiomas made up the largest subgroup of tumours, accounting for 35.1% of all tumours. In order of decreasing frequency, the remaining most often reported histologies were pituitary adenomas (11.8%), secondary neoplasms (10%), tumours of nerve sheath (9.4%), glioblastoma multiforme (9.3%), astrocytomas including anaplastic, diffuse and pilocytic (9.2%), primary CNS lymphomas (2.9%), oligodendrogliomas (2.2%), hemangioblastomas (2. 2%), craniopharyngiomas (1.7%), and embryonal tumours (1.2%). Genetic and environmental factors may be responsible for the proportionately higher than expected percentage of meningiomas seen and further study is required to identify these factors.