Re-emphasising the importance of histopathological diagnosis in suspected bacterial endocarditis.

Infective endocarditis (IE) carries a high risk of morbidity and mortality. Timely diagnosis, effective treatment and prompt recognition of complications are essential to favourable patient outcomes. A collaborative, multidisciplinary team approach to the management of IE has been shown to improve prognosis. However, the clinical heterogeneity of IE and atypical presentations pose challenges to the endocarditis team. We present a case highlighting the role of valve histopathology in suspected IE, where there may be diagnostic uncertainty.

Surgical Management of Patients with Neuroendocrine Neoplasms of the Appendix: Appendectomy or More.

BACKGROUND: Appendiceal neuroendocrine neoplasms (ANEN) are mostly indolent tumours treated effectively with simple appendectomy. However, controversy exists regarding the necessity of oncologic right hemicolectomy (RH) in patients with histologic features suggestive of more aggressive disease. We assess the effects of current guidelines in selecting the surgical strategy (appendectomy or RH) for the management of ANEN. Methods/Aims: This is a retrospective review of all ANEN cases treated over a 14-year period at 3 referral centres and their management according to consensus guidelines of the European and the North American Neuroendocrine Tumor Societies (ENETS and NANETS, respectively). The operation performed, the tumour stage and grade, the extent of residual disease, and the follow-up outcomes were evaluated. RESULTS: Of 14,850 patients who had appendectomies, 215 (1.45%) had histologically confirmed ANEN. Four patients had synchronous non-ANEN malignancies. One hundred and ninety-three patients had index appendectomy. Seventeen patients (7.9%) had lymph node metastases within the mesoappendix. Forty-nine patients underwent RH after appendectomy. The percentages of 30-day morbidity and mortality after RH were 2 and 0%, respectively. Twelve patients (24.5%) receiving completion RH were found to have lymph node metastases. Two patients had liver metastases, both of them synchronous. The median follow-up was 38.5 months (range 1-143). No patient developed disease recurrence. Five- and 10-year overall survival for all patients with ANEN as the only malignancy was both 99.05%. CONCLUSIONS: The current guidelines appear effective in identifying ANEN patients at risk of harbouring nodal disease, but they question the oncological relevance of ANEN lymph node metastases. RH might present an overtreatment for a number of patients with ANEN.

Chondroid lipoma: an update and review.

Chondroid lipoma is a rare, benign soft tissue tumor with features of both embryonal fat and embryonal cartilage that most often arises in the proximal limb and limb girdles of adult women. Histologically, it comprises nests and cords of rounded cells with granular eosinophilic or multivacuolated, lipid-containing cytoplasm within prominent myxohyaline stroma and may be morphologically confused with some sarcomas. Correct diagnosis is crucial to avoid overtreatment because it does not recur or metastasize, and simple excision is curative. The etiology of chondroid lipoma remains unknown, but it appears genetically distinct, with a reciprocal t(11;16)(q13;p13) translocation identified in an increasing number of cases. We review the literature on chondroid lipoma, discussing tumor histology, immunohistochemistry, ultrastructure, and differential diagnosis, and summarize the molecular genetic features so far known.

The Vanishing Adrenal Glands: A Transient Regression of Adrenal Lymphoma After a Single Dose of 1 mg Dexamethasone.

OBJECTIVE: Dexamethasone is a known treatment for lymphoma, but the potency and rapidity of its effect have not been recognized. We present a case of bilateral adrenal lymphoma that significantly reduced in size after a single dose of dexamethasone. METHODS: We present the clinical course and investigations, including adrenocorticotropic hormone, cortisol, short synacthen test, computed tomography (CT), and adrenal biopsy results. RESULTS: A 52-year-old man had a fall and was incidentally found to have bilateral adrenal masses (left, 6 cm; right, 5 cm) on CT. His adrenal function tests included plasma metanephrines (normetanephrine, 830 pmol/L [normal, <1180]; metanephrine, <100 pmol/L [<510]; 3-methoxytyramine, <100 pmol/L [<180]); aldosterone, 270 pmol/L( 90-700); and random cortisol, 230 nmol/L (160-550). An overnight dexamethasone suppression test with 1 mg of dexamethasone showed cortisol of <28 nmol/L (0-50). A repeat CT scan 8 days thereafter showed adrenal masses of 4.5 and 3.5 cm on the left and right, respectively. He had a follow-up CT scan 3 months later that showed adrenal lesions measuring 8 cm (left) and 9 cm (right). He subsequently presented with fatigue and dizziness. Morning cortisol of 201 nmol/L (160-550) with adrenocorticotropic hormone of 216 ng/L (10-30) indicated primary adrenal insufficiency. Mineralocorticoid and glucocorticoid replacement therapy commenced. An adrenal biopsy showed abnormal enlarged B cells, consistent with a diagnosis of diffuse large B-cell lymphoma. CONCLUSION: A diagnosis of lymphoma should be considered when adrenal lesions shrink following even a single low dose of dexamethasone administered as a part of a diagnostic test.

A rare cause of severe Cushing's syndrome.

SUMMARY: Ectopic adrenocorticotropic hormone (ACTH) production is an uncommon cause of Cushing's syndrome and, rarely, the source can be a phaeochromocytoma. A 55-year-old man presented following an episode of presumed gastroenteritis with vomiting and general malaise. Further episodes of diarrhoea, joint pains and palpitations followed. On examination, he was hypertensive with no clinical features to suggest hypercortisolaemia. He was subsequently found to have raised plasma normetanephrines of 3.98 nmol/L (NR <0.71) and metanephrines of 0.69 nmol/L (NR <0.36). An adrenal CT showed a 3.8 cm right adrenal nodule, which was not MIBG-avid but was clinically and biochemically consistent with a phaeochromocytoma. He was started on alpha blockade and referred for right adrenalectomy. Four weeks later, on the day of admission for adrenalectomy, profound hypokalaemia was noted (serum potassium 2.0 mmol/L) with non-specific ST-segment ECG changes. He was also diagnosed with new-onset diabetes mellitus (capillary blood glucose of 28 mmol/L). He reported to have gained weight and his skin had become darker over the course of the last 4 weeks. Given these findings, he underwent overnight dexamethasone suppression testing, which showed a non-suppressed serum cortisol of 1099 nmol/L. Baseline serum ACTH was 273 ng/L. A preliminary diagnosis of ectopic ACTH secretion from the known right-sided phaeochromocytoma was made and he was started on metyrapone and insulin. Surgery was postponed for 4 weeks. Following uncomplicated laparoscopic adrenalectomy, the patient recovered with full resolution of symptoms. LEARNING POINTS: Phaeochromocytomas are a rare source of ectopic ACTH secretion. A high clinical index of suspicion is therefore required to make the diagnosis. Ectopic ACTH secretion from a phaeochromocytoma can rapidly progress to severe Cushing's syndrome, thus complicating tumour removal. Removal of the primary tumour often leads to full recovery. The limited literature suggests that the presence of ectopic Cushing's syndrome does not appear to have any long-term prognostic implications.

Aberrant positivity for CD79a in erythroid lineage cells--a finding observed in a subset of re-staging bone marrow trephine biopsies after treatment cell pain.

Aberrant expression of CD79a has been reported in neoplastic cells in peripheral T cell lymphoma, T-cell acute lymphoblastic leukemia and acute myeloid leukemia (especially those with t(8;21)). In this report, we document the first report of CD79a positivity in erythroid precursor cells in bone marrow. In all, we document this finding in five of 18 re-staging bone marrow trephine samples in patients of lymphoma treated with chemotherapy (one index case and 17 additional validation cases). It is important to appreciate this finding especially in rituximab treated patients where one tends to rely on CD79a to identify minimal marrow disease.

Anaplastic Spindle Cell Squamous Carcinoma Arising from Tall Cell Variant Papillary Carcinoma of the Thyroid Gland: A Case Report and Review of the Literature.

Tall cell variant (TCV) of papillary thyroid carcinoma (PTC), an aggressive form of thyroid cancer, is characterised by 50% of cells with height that is three times greater than the width. Very rarely, some of these cancers can progress to spindle cell squamous carcinoma (SCSC) resulting in cancers with elements of both SCSC and TCV PTC. Here we report a case of SCSC arising from TCV PTC. In addition to this case, we have performed a literature review and compiled all published reports of SCSC arising from TCV PTC, including the nature of treatment and the prognosis for each of the 20 patients recorded. This is intended for use as a guide for clinicians in what the most appropriate treatment options may be for a newly diagnosed patient. Due to the rarity coupled with diagnosis occurring at a very advanced stage of disease progression, performing clinical trials is difficult and therefore drawing conclusions on optimal treatment methods remains a challenge.

Diagnostic Utility of Lymphoid Enhancer Binding Factor 1 Immunohistochemistry in Small B-Cell Lymphomas.

OBJECTIVES: Recent studies have shown that lymphoid enhancer binding factor 1 (LEF1) is a useful marker for chronic lymphocytic B-cell leukemia (CLL)/small lymphocytic lymphoma. Yet, it is not still being widely used in a diagnostic setting. In this study, we document the experience with LEF1 immunohistochemistry during routine diagnostics. METHODS: In total, 191 B-cell lymphoma cases from Hammersmith Hospital, Imperial College NHS Healthcare Trust (London, UK) were investigated by immunohistochemistry for LEF1 during routine diagnostic workup. These cases included both bone marrow trephines and lymph node biopsy specimens. The monoclonal antibody clone EPR2029Y was used. RESULTS: LEF1 expression was strong and diffuse (>70% of cells) in most cases. Few CLL cases showed a staining in proliferation centers only. Seventy-seven of 80 CLL cases expressed LEF1. Other entities expressing LEF1 included one of 38 follicular lymphomas, two of 33 marginal zone lymphomas, and one diffuse large B-cell lymphoma with a background of follicular lymphoma grade 3B. Sensitivity for LEF1 for the diagnosis of CLL was 0.96, and specificity was 0.93. CONCLUSIONS: In this study, we could demonstrate the diagnostic utility of LEF1. LEF1 is a sensitive and specific marker for CLL and is helpful in the diagnosis of diagnostically challenging small B-cell lymphomas.

MicroRNAs associated with small bowel neuroendocrine tumours and their metastases.

Novel molecular analytes are needed in small bowel neuroendocrine tumours (SBNETs) to better determine disease aggressiveness and predict treatment response. In this study, we aimed to profile the global miRNome of SBNETs, and identify microRNAs (miRNAs) involved in tumour progression for use as potential biomarkers. Two independent miRNA profiling experiments were performed (n=90), including primary SBNETs (n=28), adjacent normal small bowel (NSB; n=14), matched lymph node (LN) metastases (n=24), normal LNs (n=7), normal liver (n=2) and liver metastases (n=15). We then evaluated potentially targeted genes by performing integrated computational analyses. We discovered 39 miRNAs significantly deregulated in SBNETs compared with adjacent NSB. The most upregulated (miR-204-5p, miR-7-5p and miR-375) were confirmed by qRT-PCR. Two miRNAs (miR-1 and miR-143-3p) were significantly downregulated in LN and liver metastases compared with primary tumours. Furthermore, we identified upregulated gene targets for miR-1 and miR-143-3p in an existing SBNET dataset, which could contribute to disease progression, and show that these miRNAs directly regulate FOSB and NUAK2 oncogenes. Our study represents the largest global miRNA profiling of SBNETs using matched primary tumour and metastatic samples. We revealed novel miRNAs deregulated during SBNET disease progression, and important miRNA-mRNA interactions. These miRNAs have the potential to act as biomarkers for patient stratification and may also be able to guide treatment decisions. Further experiments to define molecular mechanisms and validate these miRNAs in larger tissue cohorts and in biofluids are now warranted.

A tetramer-octamer equilibrium in Mycobacterium leprae and Escherichia coli RuvA by analytical ultracentrifugation.

In the context of the bacterial RuvABC system, RuvA protein binds to and is involved in the subsequent processing of a four-way DNA structure called Holliday junction that is formed during homologous recombination. Four crystal structures of RuvA from Escherichia coli (EcoRuvA) showed that it was tetrameric, while neutron scattering and two other crystal structures for RuvA from Mycobacterium leprae (MleRuvA) and EcoRuvA showed that it was an octamer. To clarify this discrepancy, sedimentation equilibrium experiments by analytical ultracentrifugation were carried out and the results showed that MleRuvA existed as a tetramer-octamer equilibrium between 0.2-0.5 mg/ml in 0.1 M NaCl with a dissociation constant of 4 muM, and is octameric at higher concentrations. The same experiments in 0.3 M NaCl showed that MleRuvA is a tetramer up to 3.5 mg/ml, indicating that salt bridges are involved in octamer formation. Sedimentation equilibrium experiments with EcoRuvA showed that it was tetrameric at low concentration in both salt buffers but the protein was insoluble at high-protein concentrations in 0.1 M NaCl. It is concluded that free RuvA exists in an equilibrium between tetrameric and octameric forms in the typical concentration range and buffer found in bacterial cells.

Sporadic medullary thyroid carcinoma with a pedunculated intraluminal internal jugular vein recurrence: A case report and literature review.

Medullary thyroid carcinoma (MTC) is an uncommon usually slowly progressing neuroendocrine tumour that arises from calcitonin (CT) producing parafollicular C cells of the thyroid gland. It accounts for approximately 5% of all thyroid cancers. The majority of MTCs are sporadic (75%) whilst 25% are part of the MEN 2 hereditary syndrome (MEN 2A and MEN 2B and familial MTC). Mutations of the proto-oncogene, RET (Rearranged during Transfection), found on chromosome 10q11, are present in more than 95% of hereditary MTCs and about 25% of sporadic MTCs. MTC metastasizes primarily via lymphatic spread, to central, and lateral nodal neck compartments and the anterior and superior mediastinum. Distant haematogenous spread targets the lungs, liver, bone and brain, and is presumed to be secondary to a lymphatic pathway. There are no previously documented reports of a focal pedunculated metastases located within the jugular vein. We present the first reported case of a metastatic MTC lesion found in the right internal jugular vein in a man with recurrent MTC.

Diagnostic utility of p16, CDK4, and MDM2 as an immunohistochemical panel in distinguishing well-differentiated and dedifferentiated liposarcomas from other adipocytic tumors.

Adipocytic tumors are the most common type of soft tissue neoplasms. Distinguishing atypical lipomatous tumor-well-differentiated liposarcoma (WDL) from benign adipocytic neoplasms and dedifferentiated liposarcoma (DDL) from pleomorphic or myxoid liposarcoma (LPS) can be difficult. WDL and DDL characteristically harbor amplifications of the MDM2 and CDK4 cell cycle oncogenes with protein overexpression and can also overexpress the cell cycle regulator p16. We assessed the utility of immunohistochemistry for CDK4, MDM2, and p16 in the routine histopathologic diagnosis of WDL/DDL from other adipocytic tumors. Immunohistochemistry for the trio of markers was performed on 216 adipocytic neoplasms (31 WDLs, 57 DDLs, 11 myxoid LPS, 2 pleomorphic LPS, 91 lipomas (including intramuscular, fibro, angio, and ossifying subtypes), 18 spindle/pleomorphic lipomas, and 6 hibernomas. Sixty-eight percent of WDLs and 72% of DDLs expressed all 3 antigens, whereas 100% of WDLs and 93% of DDLs expressed at least 2 antigens. The sensitivity and specificity of the trio for detecting WDLs/DDLs were 71% and 98%, respectively. The sensitivity and specificity of CDK4 for detecting WDLs/DDLs were 86% and 89%, those of MDM2 were 86% and 74%, and those of p16 were 93% and 92%, respectively. The immunohistochemical trio of CDK4, MDM2, and p16 is a useful ancillary diagnostic tool that provides strong support in distinguishing WDLs and DDLs from other adipocytic neoplasms and is potentially more sensitive than previously assessed combinations of CDK4 and MDM2. p16 was the most sensitive and specific marker for detecting WDL/DDL, and the combination of CDK4 and p16 is of more discriminatory value than the combination of either with MDM2, the least sensitive and specific of the 3 markers.

Oncocytic adrenal cortical carcinosarcoma with pleomorphic rhabdomyosarcomatous metastases.

Adrenal cortical carcinosarcoma is a rare variant of adrenal cortical carcinoma. Sarcomatous change in adrenal cortical carcinomas is exceptionally rare, with only 9 cases previously described. Adrenal cortical carcinosarcomas tend to be aggressive tumors, with locoregional recurrence and rapid metastases from the sarcomatoid component. We describe what seems to be the first case of sarcoma arising in oncocytic adrenal cortical carcinoma. The sarcomatous component here was pleomorphic rhabdomyosarcoma. This occurred in a 45-year-old man who had nodal and pulmonary metastases of the rhabdomyosarcomatous component at presentation and who died of progressive disease 11 months later. Here, we discuss the clinical, radiologic, and pathologic findings and review the literature on adrenal cortical carcinosarcomas.