Scurvy and Tinea Corporis Simulating Leukocytoclastic Vasculitis.

ABSTRACT: Leukocytoclastic vasculitis (LCV) is a small vessel inflammatory condition considered to be caused by circulating immune complexes and often occurs after an acute infection or exposure to a new medication, although it may be associated with an underlying systemic disease or be idiopathic in nature. It is important to determine the etiology, identify the extent of the disease for early intervention and appropriate management, and treat and/or eliminate the underlying cause. Here, we report cases of scurvy and tinea corporis that presented with histopathologic features of LCV and had significant clinical improvement with treatment of the underlying etiologies. These cases emphasize that histopathologic features of early evolving LCV may be seen in other settings including scurvy and tinea corporis. Appropriate treatment of the underlying condition is important for optimized patient management.

MYC protein expression does not correlate with MYC abnormalities detected by FISH but predicts an unfavorable prognosis in de novo acute myeloid leukemia.

While dysregulation of MYC has been implicated in acute myeloid leukemia (AML), the impact of MYC protein expression in AML is less well understood. We investigated the correlation of MYC protein expression by immunohistochemistry (MYC-IHC) with MYC abnormalities and prognosis in adult de novo AML. MYC-IHC in bone marrow of patients with untreated AML (n = 58) was assessed and scored as MYClow (0-40 % of blasts) or MYChigh (> 40 % of blasts). This was correlated with MYC abnormalities by fluorescence in situ hybridization (FISH) and prognosis in the context of cytogenetic risk stratification. Residual myeloid disease at the end of induction was assessed by flow cytometry. MYClow and MYChigh were detected in 24 (41 %) and 34 cases (59 %), respectively. Extra copies of MYC were present in 12 % of cases and were not correlated with level of MYC-IHC. No cases had MYC translocation or amplification. Compared to MYClow patients, MYChigh patients had a shorter overall survival in all cytogenetic risk groups (68 vs. 21 months, p = 0.006) and in the intermediate risk group (61 vs. 21 months, p = 0.046). MYChigh patients had a tendency towards detected residual disease at the end of induction in all cytogenetic risk and intermediate risk groups. Regardless of the underlying mechanisms of MYC dysregulation, high level of MYC protein is expressed in the majority of AML and correlated to worse prognosis. Further studies on MYC dysregulation in leukemogenesis and therapy targeting MYC aberration are warranted.

Primary angiosarcoma of thyroid.

Mesenchymal origin of primary thyroid angiosarcomas (TAS) is extremely rare and comprises less than 1% of primary thyroid cancer worldwide. While TAS are most commonly occurring in the Alpine region, there are multiple reported cases of TAS in non-Alpine regions. Diagnosis of TAS is commonly made after thyroidectomy as cytologic diagnosis can be challenging due to paucity of cells, presence of necrosis and unawareness of the disease due to rarity. We report a case of primary TAS diagnosed by cytology in a 56-year-old man who presented with a sudden onset of left neck pain, swelling and haemoptysis. He was later noted to have suspicious nodules on both lobes of thyroid on ultrasound. Fine needle aspiration of thyroid nodules showed malignant epithelioid cells. The diagnosis of TAS was made based on positive endothelial markers such as thrombomodulin and CD31, with many pertinent negatives, including negative cytokeratins,thyroid transcription factor (TTF1), thyroglobulin, calcitonin and carcinoembryonic antigen (CEA).

Langerhans Cell Histiocytosis Shows Distinct Cytoplasmic Expression of Major Histocompatibility Class II Antigens.

OBJECTIVES: Langerhans cell histiocytosis (LCH) is a monoclonal proliferation of antigen presenting cells (APC). In benign APCs, antigen loading occurs in the Major Histocompatibility class II (MHCII)-lysosomal compartment of the endocytic pathway followed by transport to the cell surface upon antigen stimulation. The pattern of MHC II expression in LCH is not well characterized. METHODS: The cellular localization of MHCII was determined using immunohistochemisty (IHC). Staining pattern for the representative MHCII molecule, HLA-DR, (cell surface, cytoplasmic granular, or cytoplasmic globular) and intensity (0 to 3+) were recorded for normal tissues and 44 LCH samples along with available clinicopathologic features. Results were confirmed with a different antibody to confirm the appearance. RESULTS: In the normal tissue survey, strong HLA-DR cell surface expression was present on APCs, benign B cells, some T cells, and pulmonary macrophages. A granular cytoplasmic staining pattern (without surface expression) was seen in benign Langerhans cells (LCs) in the skin and histiocytes. Strikingly, all 44 LCH samples demonstrated both cytoplasmic granular and an unusual "globular" staining pattern with no surface staining. CONCLUSION: This is the first report of a highly specific HLA-DR staining pattern in LCH detected by IHC. The cytoplasmic perinuclear globular localization of MHCII may possibly be useful in diagnostics and may result from an immature/antigen-naïve differentiation state of the neoplastic cell.

Adenocarcinoma of the urethra with mucinous features.

Primary adenocarcinoma of the female urethra is a rare malignancy. Previous studies hypothesize multiple origins, including periurethral glands or intestinal metaplasia. We report a case of a 60-year-old white woman with adenocarcinoma of the urethra who initially presented with obstructive voiding complaints secondary to a urethral mass. Wide local excision revealed invasive adenocarcinoma of the urethra with mucinous features. There was intestinal metaplasia adjacent to the tumor, as well as separate identification of intestinal metaplasia along the urethra. Ultimately, the patient underwent radical cystectomy with ileal conduit urinary diversion with no evidence of recurrence, indicating the role of early identification and surgical intervention for such cases.

BCL2 antibodies targeted at different epitopes detect varying levels of protein expression and correlate with frequent gene amplification in diffuse large B-cell lymphoma.

Patients with aggressive, BCL2 protein-positive (+) diffuse large B-cell lymphoma (DLBCL) often experience rapid disease progression that is refractory to standard therapy. However, there is potential for false-negative staining of BCL2 using the standard monoclonal mouse 124 antibody that hinders the identification of these high-risk DLBCL patients. Herein, we compare 2 alternative rabbit monoclonal antibodies (E17 and SP66) to the 124 clone in staining for BCL2 in formalin-fixed, paraffin-embedded DLBCL tissues. Overall, in 2 independent DLBCL cohorts, E17 and SP66 detected BCL2 expression more frequently than 124. In the context of MYC expression, cases identified as BCL2 (+) with SP66 demonstrated the strongest correlation with worse overall survival. The 124 clone failed to detect BCL2 expression in the majority of translocation (+), amplification (+), and activated B-cell DLBCL cases in which high levels of BCL2 protein are expected. Using dual in situ hybridization as a new tool to detect BCL2 translocation and amplification, we observed similar results as previously reported for fluorescence in situ hybridization for translocation but a higher amplification frequency, indicating that BCL2 amplification may be underreported in DLBCL. Among the discrepant cases, phosphorylation of BCL2 at T69 and/or S70 was more common than in the concordant cases and may contribute to the 124 false negatives, in addition to previously associated mutations within the epitope region. The accurate detection of BCL2 expression is important in the prognosis and treatment of DLBCL particularly with new anti-BCL2 therapies.