NK cell enteropathy: a case report with 10 years of indolent clinical behaviour.

AIMS: Natural killer (NK) cell enteropathy is a recently described clinically indolent condition characterised by atypical NK cell infiltrates in the gastrointestinal mucosa that mimics malignant lymphoma. We report a case that highlights the indolent clinical behaviour by documenting absence of clinical progression over 10 years. METHODS AND RESULTS: We report the case of a 69-year old female who had clinically long-standing abdominal pain and recurrent mucosal ulcerations associated with atypical NK cell infiltrates. The clinical, morphologic and immunophenotypical findings in this case were diagnostic of NK cell enteropathy. Review of the patient's prior biopsies demonstrated that this persisted without clinical progression for 10 years, confirming the clinical indolent course. CONCLUSION: Recognition of NK cell enteropathy is important to avoid over-diagnosing this benign condition as an aggressive lymphoma.

Epithelioid Myofibroblastoma of the Breast: A Report of Two Cases with Discussion of Diagnostic Pitfalls.

Mesenchymal lesions of the breast are uncommon lesions which present diagnostic dilemmas for even the most experienced pathologists. Here, we present two cases of the epithelioid-variant of myofibroblastoma which were misdiagnosed as malignant lesions. Careful integration of clinical presentation, imaging, and close examination of the gross, histologic, and immunohistochemical findings can assist in differentiating these challenging lesions and avoiding diagnostic pitfalls.

MyD88-dependent expansion of an immature GR-1(+)CD11b(+) population induces T cell suppression and Th2 polarization in sepsis.

Polymicrobial sepsis alters the adaptive immune response and induces T cell suppression and Th2 immune polarization. We identify a GR-1(+)CD11b(+) population whose numbers dramatically increase and remain elevated in the spleen, lymph nodes, and bone marrow during polymicrobial sepsis. Phenotypically, these cells are heterogeneous, immature, predominantly myeloid progenitors that express interleukin 10 and several other cytokines and chemokines. Splenic GR-1(+) cells effectively suppress antigen-specific CD8(+) T cell interferon (IFN) gamma production but only modestly suppress antigen-specific and nonspecific CD4(+) T cell proliferation. GR-1(+) cell depletion in vivo prevents both the sepsis-induced augmentation of Th2 cell-dependent and depression of Th1 cell-dependent antibody production. Signaling through MyD88, but not Toll-like receptor 4, TIR domain-containing adaptor-inducing IFN-beta, or the IFN-alpha/beta receptor, is required for complete GR-1(+)CD11b(+) expansion. GR-1(+)CD11b(+) cells contribute to sepsis-induced T cell suppression and preferential Th2 polarization.

Bilateral adnexal masses: A case report of acute myeloid leukemia presenting with myeloid sarcoma of the ovary and review of literature.

•We report a case of a patient with acute myeloid leukemia (AML) presenting as myeloid sarcoma.•This patient with bilateral adnexal masses was managed via total robotic hysterectomy with bilateral salpingo-oophorectomy.•There are a limited number of reports of bilateral ovarian occurrences that exist in the literature.•Myeloid sarcoma of the ovaries may present with vaginal bleeding to dysmenorrhea, dysuria, and palpable abdominal mass.

Smoothelin immunohistochemistry is a useful adjunct for assessing muscularis propria invasion in bladder carcinoma.

AIMS: To prospectively evaluate the utility of smoothelin immunohistochemical expression for the evaluation of muscularis propria (MP) in diagnostic transurethral resection of bladder tumour (TURBT) specimens and cystectomies. METHODS AND RESULTS: Smoothelin immunohistochemistry was performed on a total of 26 TURBT and cystectomy specimens. All but two cases (24/26) demonstrated strong (3+) or moderate (2+) immunoreactivity of the MP with smoothelin. Muscularis mucosae (MM) never displayed strong (3+) reactivity, and in only one case did the MM have moderate (2+) reactivity; in this case the MP had strong (3+) reactivity. MM intensity mirrored the intensity of reactivity of blood vessels in all cases (26/26). Using moderate or strong immunoreactivity as a cut-off, smoothelin had a sensitivity of 92% for detecting MP and a specificity of 97% for distinguishing between MP and MM. In all unequivocal MP-invasive and lamina proporia-invasive cases by haematoxylin and eosin (H&E), smoothelin immunohistochemistry confirmed the original light microscopic diagnosis. In four cases in which there was equivocal MP involvement by H&E, smoothelin helped establish MP invasion. CONCLUSIONS: Smoothelin immunohistochemistry has diagnostic utility in the evaluation of MP invasion in urothelial carcinoma. Smoothelin could be used as an adjunct to traditional H&E-stained light microscopy and may help reduce the number of equivocal diagnoses.

Thrombotic storm in Kimura disease.

We report herein a patient with Kimura disease who experienced life threatening visceral venous thromboses and a clinical course fitting the description of "thrombotic storm". Kimura disease is an indolent chronic inflammatory disease common in Asians and characterized by angiolymphoid proliferation with ample eosinophil infiltration, peripheral blood eosinophilia and elevated serum immunoglobulin E levels. The clinical course of the disease is thought to be benign. Our patient experienced a major thrombotic event with a thorough evaluation revealing no evidence of inherited thrombophilia or acquired conditions associated with visceral venous thromboembolism. Despite persisting eosinophilia and other manifestations of Kimura disease there have been no recurrent thrombotic events with continuous warfarin therapy over a 4-year period. This case highlights the occurrence of hypercoagulability in association with this unusual eosinophilic disorder.

Identification of c-kit gene mutations in primary adenoid cystic carcinoma of the salivary gland.

The CD117 (KIT) protein is overexpressed in many human neoplasms including adenoid cystic carcinoma of salivary glands. To evaluate the function of c-kit-activating mutations in adenoid cystic carcinoma of the salivary gland, we studied 14 cases (13 primary, 1 cervical lymph node metastasis) from our institution. KIT protein expression was evaluated by immunohistochemistry using formalin-fixed paraffin-embedded tissue. Mutational analyses of c-kit extracellular (exon 9), juxtamembrane (exon 11) and tyrosine kinase domains (exons 13 and 17) were performed by polymerase chain reaction, clonal selection and DNA sequencing. All 14 cases demonstrated strong KIT expression by immunohistochemistry. Molecular analysis was successful in 8 of 14 cases, and c-kit missense point mutations were detected in seven of eight cases (88%) including seven in exon 11, two in exon 9, two in exon 13 and two in exon 17. Eight silent point mutations were detected in five cases. Two cases contained missense mutations in more than one exon. Different mutations were found in the primary tumor and the cervical lymph node metastasis of one patient. Point mutations in domains similar to those described in gastrointestinal stromal tumors were detected, including Pro551Leu and Lys558Glu (5' end of exon 11), Leu576Phe (3' end of exon 11), Val643Ala (exon 13) and Asn822Ser (exon 17). Additional novel point mutations in exons 9, 11, 13 and 17 were also identified. This study is the first to report c-kit gene mutations in primary adenoid cystic carcinoma of the salivary gland. Identification of such potential gain-of-function mutations in exon 11, and less frequently in exons 9, 13 and 17, suggests that KIT may be involved in the pathogenesis of adenoid cystic carcinoma of salivary glands. Our study raises a prospect of correlation of c-kit mutation and a potential treatment of adenoid cystic carcinoma with tyrosine kinase inhibitor (imatinib).

Acral myxoinflammatory fibroblastic sarcomas: are they all low-grade neoplasms?

Acral myxoinflammatory fibroblastic sarcoma (AMIFS) is a low-grade sarcoma that presents mostly in distal extremities of middle-aged patients. The clinicopathologic features, immunohistochemical profile and follow-up data of five cases (three men and two women; age 39-65 years) are presented. The tumors presented as a slow-growing, poorly circumscribed, subcutaneous masses in the hands (three), foot (one) and calf (one), with dermal involvement in two cases. They had myxoid and hyaline stroma with dense acute and chronic inflammation. Spindle cells, large bizarre ganglion-like cells and multivacuolated cells were seen. Variable reactivity in lesional cells were noted for vimentin, Alpha-1-antitrypsin (A1AT), factor XIIIa, CD68, CD95, CD117, Alpha-1-antichymotrypsin (A1ACT), CD34, AE1/3, S-100 protein, EBER, CD63 and CD15. MIB-1 showed 5-30% nuclear labeling. They were negative for cytokeratin AE1/3, smooth muscle actin, CD30, ALK-1, EMA, desmin, CMV, HMB-45 and Melan-A. Follow up ranged from 2 weeks to 95 months (mean 54). One patient was lost to follow up; three underwent excision and one patient had below the knee amputation. Two patients developed metastases (one died of disease), and two patients are alive without evidence of disease. AMIFS are rare tumors that may involve joints and tendons leading to clinical diagnosis of ganglion cyst or tenosynovitis.

Assessment of bone marrow plasma cell infiltrates in multiple myeloma: the added value of CD138 immunohistochemistry.

Assessment of bone marrow involvement by malignant plasma cells is an important element in the diagnosis and follow-up of patients with multiple myeloma and other plasma cell dyscrasias. Microscope-based differential counts of bone marrow aspirates are used as the primary method to evaluate bone marrow plasma cell percentages. However, multiple myeloma is often a focal process, a fact that impacts the accuracy and reliability of the results of bone marrow plasma cell percentages obtained by differential counts of bone marrow aspirate smears. Moreover, the interobserver and intraobserver reproducibility of counting bone marrow plasma cells microscopically has not been adequately tested. CD138 allows excellent assessment of plasma cell numbers and distribution in bone marrow biopsies. We compared estimates of plasma cell percentages in bone marrow aspirates and in hematoxylin-eosin- and CD138-stained bone marrow biopsy sections (CD138 sections) in 79 bone marrows from patients with multiple myeloma. There was a notable discrepancy in bone marrow plasma cell percentages using the different methods of observation. In particular, there was a relatively poor concordance of plasma cell percentage estimation between aspirate smears and CD138 sections. Estimates of plasma cell percentage using CD138 sections demonstrated the highest interobserver concordance. This observation was supported by computer-assisted image analysis. In addition, CD138 expression highlighted patterns of plasma cell infiltration indicative of neoplasia even in the absence of plasmacytosis. We conclude that examination of CD138 sections should be considered for routine use in the estimation of plasma cell load in the bone marrow.

Discordant expression of CD20 by flow cytometry and immunohistochemistry in a patient responding to rituximab: an unusual mechanism.

Immunohistochemistry using the L26 antibody recognizes an intracellular domain of CD20, whereas the L27 antibody used for surface CD20 staining by flow cytometry (FC) recognizes an extracellular domain and would be expected to be a better predictor of response to rituximab. We present a 75-year-old man who was initially treated for CD20- diffuse large B-cell lymphoma based on FC and, at relapse, still had CD20- disease by FC but CD20+ disease by immunohistochemistry. The patient responded to rituximab alone. On further study, it was shown that the malignant B cells, but not normal B cells, expressed the L27 surface binding site only within the intracellular domain. Therefore, it appears that the rituximab binding site is distinct from the surface binding site, and when there is a disparity between the methods to detect CD20 expression, consideration should be given to include rituximab in the treatment plan.

Xp11 Translocation Renal Cell Carcinoma: Unusual Variant Masquerading as Upper Tract Urothelial Cell Carcinoma.

Xp11 translocation renal cell carcinoma (TRCC) is a rare subtype of renal cell carcinoma characterized by chromosomal translocations involving the TFE3 gene located at the Xp11.2 locus. Initial cases were more common in children, but cases in older adults have begun to accrue and suggest a relatively more aggressive course. We report a case of Xp11 TRCC in a 63-year-old female patient with initial presentation mimicking upper urinary tract urothelial cell carcinoma, with biopsy proving TRCC. She underwent a radical nephrectomy and paracaval lymph node dissection and is followed up with the intent to initiate vascular endothelial growth factor-targeted therapy in case of recurrence.

Developing aptamer probes for acute myelogenous leukemia detection and surface protein biomarker discovery.

BACKGROUND: The majority of patients with acute myelogenous leukemia (AML) still die of their disease. In order to improve survival rates in AML patients, new strategies are necessary to discover biomarkers for the detection and targeted therapy of AML. One of the advantages of the aptamer-based technology is the unique cell-based selection process, which allows us to efficiently select for cell-specific aptamers without knowing which target molecules are present on the cell surface. METHODS: The NB4 AML cell line was used as the target cell population for selecting single stranded DNA aptamers. After determining the affinity of selected aptamers to leukocytes, the aptamers were used to phenotype human bone marrow leukocytes and AML cells in clinical specimens. Then a biotin-labelled aptamer was used to enrich and identify its target surface protein. RESULTS: Three new aptamers were characterized from the selected aptamer pools (JH6, JH19, and K19). All of them can selectively recognize myeloid cells with Kd in the low nanomole range (2.77 to 12.37 nM). The target of the biotin-labelled K19 aptamer probe was identified as Siglec-5, a surface membrane protein in low abundance whose expression can serve as a biomarker of granulocytic maturation and be used to phenotype AML. More importantly, Siglec-5 expression can be used to detect low concentrations of AML cells in human bone marrow specimens, and functions as a potential target for leukemic therapy. CONCLUSIONS: We have demonstrated a pipeline approach for developing single stranded DNA aptamer probes, phenotyping AML cells in clinical specimens, and then identifying the aptamer-recognized target protein. The developed aptamer probes and identified Siglec-5 protein may potentially be used for leukemic cell detection and therapy in our future clinical practice.

Intrathyroidal parathyroid carcinoma: report of an unusual case and review of the literature.

Intrathyroidal parathyroid carcinoma is an exceedingly rare cause of primary hyperparathyroidism. A 51-year-old African American female presented with goiter, hyperparathyroidism, and symptomatic hypercalcemia. Sestamibi scan revealed diffuse activity within an enlarged thyroid gland with uptake in the right thyroid lobe suggestive of hyperfunctioning parathyroid tissue. The patient underwent thyroidectomy and parathyroidectomy. At exploration, a 2.0 cm nodule in the usual location of the right inferior parathyroid was sent for intraoperative frozen consultation, which revealed only ectopic thyroid tissue. No parathyroid glands were identified grossly on the external aspect of the thyroid. Interestingly, postoperative parathyroid hormone levels normalized after removal of the thyroid gland. Examination of the thyroidectomy specimen revealed a 1.4 cm parathyroid nodule located within the parenchyma of the right superior thyroid, with capsular and vascular invasion and local infiltration into surrounding thyroid tissue. We present only the eighth reported case of intrathyroidal parathyroid carcinoma and review the literature.

Systemic Capillary Leak Syndrome as an Initial Presentation of ALK-Negative Anaplastic Large Cell Lymphoma.

Systemic capillary leak syndrome (SCLS) is a rare disease characterized by third spacing of plasma into the extravascular compartment, leading to anasarca, hemoconcentration, and hypovolemic shock. It has been rarely associated with lymphomas, and reports usually indicate that it occurs after antineoplastic treatment. We present the case of a patient with ALK-negative anaplastic large cell lymphoma who presented with SCLS as the initial manifestation of her lymphoma. The SCLS resolved with treatment of the malignancy with steroids and chemotherapy.

Noninvasive evaluation of nuclear morphometry in breast lesions using multispectral diffuse optical tomography.

Breast cancer is the most prevalent cancer and the main cause of cancer-related death in women worldwide. There are limitations associated with the existing clinical tools for breast cancer detection and alternative modalities for early detection and classification of breast cancer are urgently needed. Here we describe an optical imaging technique, called multispectral diffuse optical tomography (DOT), and demonstrate its ability of non-invasively evaluating nuclear morphometry for differentiating benign from malignant lesions. Photon densities along the surface of the breast were measured to allow for the extraction of three statistical parameters including the size, elongation and density of nuclei inside the breast tissue. The results from 14 patients (4 malignant and 10 benign lesions) show that there exist significant contrasts between the diseased and surrounding normal nuclei and that the recovered nuclear morphological parameters agree well the pathological findings. We found that the nuclei of cancer cells were less-spherical compared with those of surrounding normal cells, while the nuclear density or volume fraction provided the highest contrast among the three statistical parameters recovered. This pilot study demonstrates the potential of multispectral DOT as a cellular imaging method for accurate determination of breast cancer.

PTK7: a new biomarker for immunophenotypic characterization of maturing T cells and T cell acute lymphoblastic leukemia.

Protein tyrosine kinase-7 (PTK7) was recently identified as a surface protein expressed on hematopoietic cells. To determine if PTK7 is a useful biomarker in clinical practice for acute leukemia immunophenotyping and detection, we examined the PTK7 expression in human bone marrow and thymic specimens. Our results show that PTK7 expression in normal thymic T cells is tightly regulated during the maturational process, but in T cell acute lymphoblastic leukemia (T-ALL) the expected temporal relationship of expression between PTK7 and other maturational T cell markers is lost or disrupted. In addition, nearly all T-ALL cases expressed higher PTK7 levels than mature T cells in the human bone marrow specimens. Therefore, in conjunction with other T cell markers, PTK7 has utility as a biomarker for detecting minimal residual disease of T-ALL in the bone marrow.

Flow cytometric analysis of immunoglobulin heavy chain expression in B-cell lymphoma and reactive lymphoid hyperplasia.

The diagnosis of B-cell lymphoma (BCL) is often dependent on the detection of clonal immunoglobulin (Ig) light chain expression. In some BCLs, the determination of clonality based on Ig light chain restriction may be difficult. The aim of our study was to assess the utility of flow cytometric analysis of surface Ig heavy chain (HC) expression in lymphoid tissues in distinguishing lymphoid hyperplasias from BCLs, and also differentiating various BCL subtypes. HC expression on B-cells varied among different types of hyperplasias. In follicular hyperplasia, IgM and IgD expression was high in mantle cells while germinal center cells showed poor HC expression. In other hyperplasias, B cell compartments were blurred but generally showed high IgD and IgM expression. Compared to hyperplasias, BCLs varied in IgM expression. Small lymphocytic lymphomas had lower IgM expression than mantle cell lymphomas. Of importance, IgD expression was significantly lower in BCLs than in hyperplasias, a finding that can be useful in differentiating lymphoma from reactive processes.