Post-Chemotherapy Histiocyte-Rich Pseudotumors: Radiologic and Endoscopic Mimics of Residual Lymphoma.

Development of post-chemotherapy histiocyte-rich pseudotumor (PHP) is an underrecognized event following therapy in lymphoma patients and may mimic residual tumor using current therapy monitoring protocols. We report a series of 5 patients with PHP along with a review of the literature. In our series, we describe 3 patients with persistent hypermetabolic masses by positron emission tomography-computed tomography, one with persistent terminal ileal nodules on endoscopy, and one with bone marrow involvement, a site not associated with mass-like disease. Twenty-three patients with long-term follow-up were identified from our series and review of the literature. Forty-four percent of patients received additional therapy, and only 4% of patients died of lymphoma. This study illustrates that PHPs are not identified using current lymphoma therapy monitoring algorithms and may result in overtreatment with risk for additional therapy-related complications. The need for confirmatory tissue biopsy in this setting is recommended.

Autoimmune Myelofibrosis: Clinical Features, Course, and Outcome.

BACKGROUND: Autoimmune myelofibrosis (AIMF) is an underrecognized cause of nonmalignant bone marrow fibrosis which occurs in the presence or absence of a defined systemic autoimmune disease. Patients with AIMF present with cytopenias and autoantibodies, and have a distinctive nonclonal myelofibrosis on bone marrow examination. AIMF is distinguished from primary myelofibrosis by the absence of splenomegaly, eosinophilia, or basophilia, and the absence of abnormal myeloid, erythroid, or megakaryocytic morphology. OBJECTIVES: The objective of the study was to describe the clinical presentation and outcomes of patients with AIMF. METHODS: We conducted a single-institution, retrospective chart review of patients diagnosed with AIMF to investigate clinical presentations, therapies, and outcomes. RESULTS: Twelve patients with AIMF were identified with a mean follow-up of 5.8 years. All patients had detectable autoantibodies and the majority had concomitant autoimmune disorders. Four patients experienced a complete response of cytopenias and 3 patients experienced a partial response (PR) of cytopenias with immunosuppressive therapy. One patient achieved a PR following splenectomy. No patients were diagnosed with myeloproliferative neoplasms during the follow-up period. CONCLUSIONS: AIMF contributes to cytopenias in the subset of patients with various autoimmune disorders. The majority of patients with AIMF experience an improvement in cytopenias with immunosuppressive therapy.

High concordance between HercepTest immunohistochemistry and ERBB2 fluorescence in situ hybridization before and after implementation of American Society of Clinical Oncology/College of American Pathology 2007 guidelines.

Human epidermal growth factor receptor 2 (HER2, ERBB2) is an important critical predictive marker in patients with invasive breast cancer. It is thus imperative to ensure accuracy and precision in HER2 and ERBB2 testing. In 2007, the American Society of Clinical Oncology and College of American Pathologists (ASCO/CAP) proposed new guidelines for immunohistochemistry and fluorescence in-situ hybridization scoring in an effort to improve accuracy and utility of these companion diagnostic tests. The goal of the 2007 guidelines was to improve concordance rates between the diagnostic tests and decrease the number of inconclusive cases. This study examines the impact in concordance rates and number of inconclusive cases based on the recent change in guidelines in a large study cohort. HER2 immunohistochemistry and ERBB2 fluorescence in-situ hybridization were performed on all specimens from our facility from years 2003 through 2010 (n=1437). Cases from 2003-2007 (n=1016) were scored using Food and Drug Administration guidelines, with immunohistochemical 3+ cases staining >10% of tumor cells and fluorescence in-situ hybridization amplification cutoff value of 2.0. The 2007 guidelines were implemented and scored accordingly for cases from 2008-2010 (n=421), with immunohistochemical 3+ cases staining >30% of tumor cells and fluorescence in-situ hybridization amplification cutoff value of 2.2. We compared concordance rates before and after 2007 guidelines. For the 2003-2007 study population, the concordance rate between the assays was 97.6% with a corresponding kappa coefficient (k) of 0.90. For the 2008-2010 study population, concordance rate was 97.6% with a corresponding k of 0.89. There was no significant difference in number of inconclusive rates before and after 2007 guidelines. In our study, implementation of the new ASCO/CAP 2007 HER2 guidelines did not show a significant difference in concordance rates and did not decrease the number of inconclusive cases.

Kikuchi-Fujimoto disease involving retroperitoneal lymph nodes: An uncommon presentation.

Kikuchi-Fujimoto disease is a self-limited disease of unknown etiology that is clinically defined by fevers accompanied by tender posterior cervical lymphadenopathy. It often presents acutely or sub-acutely, and due to its non-specific features, the differential diagnosis is broad and includes infectious, autoimmune, and malignant causes. Although cases of extra-cervical disease are not uncommon, involvement of retroperitoneal lymph nodes has only rarely been reported. Here, we describe a patient with Kikuchi-Fujimoto disease who presented with fever of unknown origin, abdominal pain, and enlarged hypermetabolic retroperitoneal lymph nodes.

Comprehensive adipocytic and neurogenic tissue microarray analysis of NY-ESO-1 expression - a promising immunotherapy target in malignant peripheral nerve sheath tumor and liposarcoma.

BACKGROUND: Immunotherapy targeting cancer-testis antigen NY-ESO-1 shows promise for tumors with poor response to chemoradiation. Malignant peripheral nerve sheath tumors (MPNSTs) and liposarcomas (LPS) are chemoresistant and have few effective treatment options. Materials Methods: Using a comprehensive tissue microarray (TMA) of both benign and malignant tumors in primary, recurrent, and metastatic samples, we examined NY-ESO-1 expression in peripheral nerve sheath tumor (PNST) and adipocytic tumors. The PNST TMA included 42 MPNSTs (spontaneous n = 26, NF1-associated n = 16), 35 neurofibromas (spontaneous n = 22, NF-1 associated n = 13), 11 schwannomas, and 18 normal nerves. The LPS TMA included 48 well-differentiated/dedifferentiated (WD/DD) LPS, 13 myxoid/round cell LPS, 3 pleomorphic LPS, 8 lipomas, 1 myelolipoma, and 3 normal adipocytic tissue samples. Stained in triplicate, NY-ESO-1 intensity and density were scored. RESULTS: NY-ESO-1 expression was exclusive to malignant tumors. 100% of myxoid/round cell LPS demonstrated NY-ESO-1 expression, while only 6% of WD/DD LPS showed protein expression, one of which was WD LPS. Of MPNST, 4/26 (15%) spontaneous and 2/16 (12%) NF1-associated MPNSTs demonstrated NY-ESO-1 expression. Strong NY-ESO-1 expression was observed in myxoid/round cell and dedifferentiated LPS, and MPNST in primary, neoadjuvant, and metastatic settings. CONCLUSIONS: We found higher prevalence of NY-ESO-1 expression in MPNSTs than previously reported, highlighting a subset of MPNST patients who may benefit from immunotherapy. This study expands our understanding of NY-ESO-1 in WD/DD LPS and is the first demonstration of staining in a WD LPS and metastatic/recurrent myxoid/round cell LPS. These results suggest immunotherapy targeting NY-ESO-1 may benefit patients with aggressive tumors resistant to conventional therapy.

Autoimmune myelofibrosis: an update on morphologic features in 29 cases and review of the literature.

Autoimmune myelofibrosis (AIMF) is a distinct clinicopathological entity associated with diffuse bone marrow fibrosis and a benign clinical course. Distinction from neoplastic etiologies of marrow fibrosis, particularly primary myelofibrosis, is imperative, but few studies have documented histopathologic features in a large series. We describe 29 patients with AIMF, defined as marrow reticulin fibrosis and lymphocytic infiltration in the context of an established autoimmune disorder (secondary AIMF) or autoantibodies without a defined disorder (primary AIMF). Excluded were cases with atypical megakaryocytes, dysplasia, basophilia, osteosclerosis, unexplained splenomegaly, or neoplasms associated with myelofibrosis (MF). All cases were stained for reticulin, CD3, and CD20, with a subset additionally stained for CD138, κ, λ, immunoglobulin G (IgG), and IgG4. Lymphoid aggregates, where present, were classified into T-cell and B-cell patterns of distribution. Most patients (93%) presented with cytopenias. Sixty-nine percent (n = 20) were considered secondary AIMF and the remainder primary AIMF (n = 9). Peripheral blood showed absent-to-rare blasts and teardrop erythrocytes and absence of eosinophilia or basophilia. Characteristic bone marrow findings included hypercellularity with erythroid and megakaryocytic hyperplasias, mild reticulin fibrosis, intrasinusoidal hematopoiesis, T-cell pattern in lymphoid aggregates, mild polytypic plasmacytosis, and absence of IgG4-positive plasma cells. Primary and secondary AIMF were pathologically indistinguishable, except for an increased incidence of granulocytic hyperplasia in primary AIMF. This series confirms and expands the utility of the original diagnostic criteria for AIMF. Recognizing the characteristic morphology of AIMF and its associated clinical and laboratory features distinguishes autoimmune from neoplastic causes of MF and guides further evaluation and management.

Comparative evaluation of ProEx C and ImmunoCyt/uCyt assays in atypical urine cytology.

CONTEXT: Detection of urothelial carcinoma by urine cytology can be challenging. Recently, ProEx C has been studied as a marker to improve detection of urothelial carcinoma. ProEx C is an assay targeting expression of topoisomerase II-α and the minichromosome maintenance protein-2 and is used to assist in diagnoses of gynecologic specimens. OBJECTIVE: To evaluate the utility of ProEx C and uCyt in atypical urine cytology. DESIGN: Sixty-eight specimens with a diagnosis of atypical urine cytology, concurrent uCyt testing, and surgical biopsy follow-up were included. Slides were restained with ProEx C. ProEx C was recorded as positive when nuclear staining was seen in at least one morphologically atypical urothelial cell. The uCyt was scored as positive if at least one morphologically atypical urothelial cell showed positive fluorescence staining. Thirteen cases (19%) had benign histologic diagnoses, 18 (26%) had low-grade papillary urothelial carcinoma, and 37 (54%) had high-grade urothelial carcinoma. RESULTS: The overall sensitivity was 85% for ProEx C, 85% for uCyt, and 93% for the combination of the 2 assays. The overall specificity was 69% for ProEx C, 31% for uCyt, and 23% for the combination of the 2 tests. In predicting high-grade urothelial carcinoma, sensitivity was 92% for ProEx C, 86% for uCyt, and 92% for both tests. In predicting low-grade papillary urothelial carcinoma, sensitivity was best with the combination of the 2 tests at 94%. CONCLUSION: ProEx C has superior specificity to uCyt. The combination of the 2 tests yielded high sensitivity not only for high-grade urothelial carcinoma but also for low-grade papillary urothelial carcinoma.

Utility of ProEx C in the histologic evaluation of the neoplastic and nonneoplastic urothelial lesions.

ProEx C is an antibody cocktail targeting the expression of topoisomerase IIα and minichromosome maintenance protein 2. ProEx C staining is being used mainly to assist in diagnoses of dysplasia in gynecological specimens. This study was designed to determine the utility of ProEx C in assessing the urothelial lesions. Sixty-four patient specimens were divided into 5 groups: group I, 22 benign; group II, 13 low-grade noninvasive papillary urothelial carcinoma; group III, 10 high-grade urothelial carcinoma in situ (flat lesion); and group IV, 19 high-grade noninvasive papillary and invasive urothelial carcinomas. ProEx C reactions were scored in basal, parabasal, intermediate, and superficial cell layers. A sample was recorded as positive when nuclear staining was seen in the cells of the intermediate and/or superficial layers. Of 22 cases in group I, 21 were negative for ProEx C with a specificity of 95%. Of 13 cases in group II, 11 had positive results with sensitivity of 85%. All cases in groups III and IV had positive staining pattern with ProEx C with a sensitivity of 100%. In this study, ProEx C stain had an overall 95% sensitivity and specificity with positive and negative predictive values of 98% and 91%, respectively, for detection of urothelial carcinoma. We conclude that ProEx C is effective in differentiating carcinoma in situ and benign urothelial lesions. It also resolves issues in low- versus high-grade papillary urothelial carcinomas. To our knowledge, this is the first publication on the diagnostic application of ProEx C in histopathology of the urothelial lesions.

A novel sarcoma with dual differentiation: clinicopathologic and molecular characterization of a combined synovial sarcoma and extraskeletal myxoid chondrosarcoma.

We report on an unusual case of a 43-year-old woman who developed a malignant soft tissue tumor of the arm with overlapping morphology between synovial sarcoma (SS) and extraskeletal myxoid chondrosarcoma (EMC). The tumor recurred 7 years after the initial diagnosis and continued to demonstrate both SS and EMC histology. Immunophenotypically, the primary and recurrent tumors were both positive, focally, for cytokeratin, S-100, bcl-2, and epithelial membrane antigen. At the time of recurrence, the primary and recurrent tumors were further characterized for genetic and molecular abnormalities. Intriguingly, fluorescence in situ hybridization of the primary tumor revealed rearrangements of both the SS18 and EWSR1 genes. Furthermore, reverse transcriptase-polymerase chain reaction studies of both the primary tumor and the recurrence confirmed the presence of both SS18-SSX2 and EWSR1-NR4A3 (exon 3) gene fusions, characteristic of SS and EMC, respectively. This is the first reported case of a remarkable soft tissue sarcoma that exhibits overlapping morphologic features between SS and EMC and that also harbors a combination of SS18-SSX2 and EWS-NR4A3 gene fusions. This case supports the fact that specific, reproducible gene fusions frequently direct, cooperatively or competitively, basic histogenetic processes to produce tumor phenotypes.