Lymphoma diagnosis at an academic centre: rate of revision and impact on patient care.

Few studies have examined the value of a mandatory second review of outside pathology material for haematological malignancies. Therefore, we compared diagnoses on biopsies referred to an academic medical centre to determine the rate and therapeutic impact of revised diagnoses resulting from a second review. We reviewed 1010 cases referred for lymphoma during 2009-2010. For each case, referral diagnosis and second review diagnosis were compared. Revised diagnoses were grouped into major and minor discrepancies and all major discrepancies were reviewed by a haematologist to determine the effect the diagnostic change would have on therapy. There was no change in diagnosis in 861 (85·2%) cases. In 149 (14·8%) cases, second review resulted in major diagnostic change, of which 131 (12·9%) would have resulted in a therapeutic change. The highest rates of revision were for follicular, high-grade B-cell, and T-cell lymphomas. We found higher rates of major discrepancy in diagnoses from non-academic centres (15·8%) compared to academic centres (8·5%; P = 0·022), and in excisional biopsies (17·9%) compared to smaller biopsies (9·6%; P = 0·0003). Mandatory review of outside pathology material prior to treatment of patients for lymphoma will identify a significant number of misclassified cases with a major change in therapy.

MYC and BCL2 protein expression predicts survival in patients with diffuse large B-cell lymphoma treated with rituximab.

Diffuse large B-cell lymphoma (DLBCL) is a heterogeneous disease and "double-hit" DLBCL, with both MYC and BCL2 translocations has a poor prognosis. In this study, we investigated whether MYC and BCL2 protein expression in tissue would predict survival in DLBCL. The study included 106 cases of de novo DLBCL treated with rituximab and cyclophosphamide, doxorubicin, vincristine and prednisone (R-CHOP) or CHOP-like regimens. The results were validated on an independent cohort of 205 DLBCL patients. Patients with low expression of BCL2 (≤30%) and MYC (≤50%) had the best prognosis, whereas those with high BCL2 (>30%) and MYC (>50%) had the worst outcome. In multivariate analysis, the combination of the BCL2 and MYC was an independent predictor of overall survival (OS) and event-free survival (EFS) (P = 0·015 and P = 0·005, respectively). The risk of death was nine times greater for patients with high BCL2 and MYC compared to those with low expression. High BCL2 and MYC was a strong predictor of poor OS (P < 0·001) and EFS (P = 0·0017) in patients with the germinal centre B-cell (GCB) type, but not in the non-GCB type. In DLBCL, high co-expression of MYC and BCL2 was an independent predictor of poor survival, and could be used to stratify patients for risk-adapted therapies.

Classification of non-Hodgkin lymphoma in Central and South America: a review of 1028 cases.

The distribution of non-Hodgkin lymphoma (NHL) subtypes differs around the world but a systematic study of Latin America has not been done. Therefore, we evaluated the relative frequencies of NHL subtypes in Central and South America (CSA). Five expert hematopathologists classified consecutive cases of NHL from 5 CSA countries using the WHO classification and compared them to 400 cases from North America (NA). Among the 1028 CSA cases, the proportions of B- and T-cell NHL and the sex distribution were similar to NA. However, the median age of B-cell NHL in CSA (59 years) was significantly lower than in NA (66 years; P < .0001). The distribution of high-grade (52.9%) and low-grade (47.1%) mature B-cell NHL in CSA was also significantly different from NA (37.5% and 62.5%; P < .0001). Diffuse large B-cell lymphoma was more common in CSA (40%) than in NA (29.2%; P < .0001), whereas the frequency of follicular lymphoma was similar in Argentina (34.1%) and NA (33.8%), and higher than the rest of CSA (17%; P < .001). Extranodal NK/T-cell NHL was also more common in CSA (P < .0001). Our study provides new objective evidence that the distribution of NHL subtypes varies significantly by geographic region and should prompt epidemiologic studies to explain these differences.

Durable partial response to pembrolizumab, lenvatinib, and letrozole in a case of recurrent uterine carcinosarcoma with ESR1 gene amplification.

•ESR1 gene amplification occurs in 7% of uterine carcinosarcoma.•The presence of ESR1 gene amplification in recurrent uterine carcinosarcoma may be targeted by aromatase inhibitors.•ESR1 gene amplification may be identified through immunohistochemical staining for estrogen receptor followed by fluorescence in situ hybridization or tumor targeted gene sequencing.

False-negative dual-energy computed tomography in a patient with acute gout.

Gout is a painful inflammatory arthropathy caused by crystallization of monosodium urate within the joints. We present the case of a patient with primary gout who had positive results of joint aspiration and synovial biopsy for monosodium urate crystals in the third metacarpophalangeal joint but false-negative results of dual-energy computed tomography.

Building Cancer Diagnosis Text to OncoTree Mapping Pipelines for Clinical Sequencing Data Integration and Curation.

Precision oncology research seeks to derive knowledge from existing data. Current work seeks to integrate clinical and genomic data across cancer centers to enable impactful secondary use. However, integrated data reliability depends on the data curation method used and its systematicity. In practice, data integration and mapping are often done manually even though crucial data such as oncological diagnoses (DX) show varying accuracy and specificity levels. We hypothesized that mapping of text-form cancer DX to a standardized terminology (OncoTree) could be automated using existing methods (e.g. natural language processing (NLP) modules and application programming interfaces [APIs]). We found that our best-performing pipeline prototype was effective but limited by API development limitations (accurately mapped 96.2% of textual DX dataset to NCI Thesaurus (NCIt), 44.2% through NCIt to OncoTree). These results suggest the pipeline model could be viable to automate data curation. Such techniques may become increasingly more reliable with further development.

Tricuspid valve and pacemaker endocarditis due to Pseudallescheria boydii (Scedosporium apiospermum).

We report a case of native valve and pacemaker endocarditis in a 78-year-old male with diabetes mellitus who died after cardiac surgery. At autopsy, tricuspid valve vegetations and lung abscesses containing thick, hyaline, septate, and branching hyphae were present. The culture identified Scedosporium apiospermum, an infrequent cause of opportunistic infections in immunocompromised hosts.

Use of Smooth Muscle Myosin Heavy Chain as an Effective Marker of Follicular Dendritic Cells.

Smooth muscle myosin heavy chain (SMMHC) is a major structural component of the contractile apparatus in smooth muscle cells. Even though it is considered a relatively specific marker for terminal smooth muscle cell differentiation, expression in other cell types such as follicular dendritic cells (FDCs) has rarely been reported. To determine whether SMMHC represents an effective FDC marker in lymphoid tissues, we compared the immunohistochemical results for SMMHC with those of the traditional FDC markers podoplanin (D2-40) and CD21. Paraffin sections of 44 lymphoid tissues were analyzed, including 31 cases of follicular hyperplasia, 6 cases of follicular lymphoma, 2 cases of peripheral T-cell lymphoma, 3 cases of diffuse large B-cell lymphoma arising in follicular lymphoma, 1 case of nodular sclerosis classical Hodgkin lymphoma, and 1 case of small lymphocytic lymphoma. There was no statistically significant difference between the number of SMMHC-positive and D2-40-positive or CD21 lymph nodes (P>0.05). The extent and intensity of SMMHC-positive FDCs were similar to those of D2-40-positive FDCs (P=0.127 and 0.733, respectively), but significantly lower compared with those of CD21 cells (P=0.009 and 0.00002, respectively). However, in contrast to CD21 which was also positive in some germinal center B cells, SMMHC expression was restricted to FDCs. Our results indicate that SMMHC is an excellent marker for FDCs and can be particularly helpful in demonstrating the underlying architecture in lymphoid processes.

Kluyvera infections in the pediatric population.

In pediatric patients, Kluyvera spp. has emerged as a cause of disease ranging from soft tissue infections to sepsis with multiorgan failure. Successful treatment options include third-generation cephalosporins, tetracycline, aminoglycosides, and fluoroquinolones, but resistance to first- and second-generation cephalosporins persists. Clinicians should be aware of the spectrum of disease and increasing clinical importance associated with this emerging pathogen.

Isolated intestinal neurofibromatous proliferations in the absence of associated systemic syndromes.

Gastrointestinal tract involvement by neurofibromatous lesions is rare and occurs most frequently as one of the systemic manifestations of generalized neurofibromatosis type 1 (NF1). In this setting, the lesions may manifest as focal scattered neurofibromas or as an extensive diffuse neural hyperplasia designated ganglioneuromatosis. Occasionally, such lesions may be the initial sign of NF1 in patients without any other clinical manifestations of the disease. Rarely, cases of isolated neurofibromatosis of the large bowel with no prior or subsequent evidence of generalized neurofibromatosis have been documented. We present the case of a 52 year-old female with abdominal pain and alternating bowel habits. Colonoscopic evaluation revealed multiple small polyps in the cecum and the presence of nodular mucosa in the colon and rectum. Pathologic evaluation of the biopsies from the cecum, descending colon, sigmoid colon, and rectum revealed tangled fascicles of spindle cells expanding the lamina propia leading to separation of the intestinal crypts. Immunohistochemical stains helped confirm the diagnosis of diffuse intestinal neurofibromatosis. A thorough clinical evaluation failed to reveal any stigmata of generalized neurofibromatosis. This case represents a rare presentation of isolated intestinal neurofibromatosis in a patient without classic systemic manifestations of generalized neurofibromatosis and highlights the need in such cases for close clinical follow-up to exclude neurofibromatosis type I or multiple endocrine neoplasia type II.

Neonatal Candida parapsilosis meningitis and empyema related to epidural migration of a central venous catheter.

Candida parapsilosis is an extremely rare cause of meningitis. We report the case of a neonate born at 26+4 weeks of gestation who was admitted to the neonatal intensive care unit at our institution due to respiratory immaturity. During the course of a 3-month hospitalization, the neonate developed fever and lethargy. A lumbar puncture revealed milky-white, turbid cerebrospinal fluid which contained many nucleated cells, mostly neutrophils. Microscopic examination of the cerebrospinal fluid revealed marked acute inflammation and fungal yeast forms, and cultures of the cerebrospinal fluid and peripheral blood yielded C. parapsilosis. Imaging studies subsequently revealed a subdural empyema related to epidural migration of a central venous catheter (CVL). The neonate received extended therapy with amphotericin B and fluconazole. He responded favorably to therapy and was discharged 3 months after birth. This case underscores the clinical importance of the recognition and treatment of a potentially lethal fungal pathogen of the central nervous system and the need for awareness of complications resulting from CVL malposition.

Follicular large cleaved cell (centrocytic) lymphoma: an unrecognized variant of follicular lymphoma.

The World Health Organization classification of lymphoma recommends the subdivision of follicular lymphoma (FL) into 3 grades (FL1-3) based on the average number of centroblasts per high-power field in the neoplastic follicles, but does not recognize a form of FL characterized by a predominance of large cleaved cells (centrocytes) without enough centroblasts to meet the World Health Organization criteria for FL3. We have classified such cases as follicular large cleaved cell lymphoma (FLC) and, herein, describe the pathologic and clinical features of 72 cases of this entity. The features of FLC include a follicular growth pattern with pale follicles at low magnification and frequent follicular and/or interfollicular fibrosis. Cytologically, the cells are predominantly large cleaved cells with moderately coarse to fine chromatin, absent or inconspicuous nucleoli, and small to moderate amounts of pale cytoplasm. The mean nuclear diameter of the large cleaved cells was 10.1µ, approximately twice that of small lymphocytes and similar to centroblasts. The t(14;18) was present in 83% of the cases, and a high proportion expressed BCL2 (84%), BCL6 (100%), and CD10 (88%) and had high Ki67 proliferation (81%). The clinical features of patients with FLC were similar to those with other types of FL, and survival was excellent with anthracycline-based chemotherapy plus rituximab. FLC is a variant of follicular lymphoma which should be recognized in future lymphoma classifications because the diagnosis of FLC may be important for the selection of therapy.

Rectal extranodal Rosai-Dorfman disease diagnosed by EUS-FNA: a case report and review of the literature.

Rosai-Dorfman disease (RDD), also known as "sinus histiocytosis with massive lymphadenopathy," only rarely involves the gastrointestinal (GI) tract. Therefore, this unusual site of presentation can be challenging for the pathologist. We present a case of RDD manifesting as a rectal submucosal mass associated with rectal bleeding in a 54 year old woman. The diagnosis was made on cytologic preparations obtained through endoscopic ultrasound guided fine needle aspiration (EUS-FNA) and subsequently confirmed by biopsy. To our knowledge, this is the first time extranodal RDD of the GI tract has been diagnosed by EUS-FNA. A review of previously published cases of GI RDD is presented to increase awareness of this exceptional presentation.

Investigation of the BRAF V600E mutation by pyrosequencing in lymphoproliferative disorders.

The presence of the BRAF c.1799T>A V600E mutation was recently described in cases of hairy cell leukemia (HCL) but not in other common lymphomas. However, many uncommon subtypes of lymphoma have not been studied. We designed a BRAF pyrosequencing assay specific for the V600E mutation, which has a sensitivity of 5% and is applicable to paraffin-embedded tissue. DNA was sequenced in 9 cases of HCL; 6 cases of variant HCL; 10 cases each of nodal marginal zone lymphoma (NMZL), extranodal marginal zone lymphoma (ENMZL), posttransplantation lymphoproliferative disorder (PTLD), and large granular lymphocyte (LGL) proliferations; 11 cases of peripheral T-cell lymphoma (PTCL); and 12 cases of anaplastic large cell lymphoma (ALCL). All (100%) cases of HCL were positive for BRAF mutations. No mutations were identified in variant HCL, NMZL, ENMZL, PTLD, PTCL, ALCL, or LGL proliferations. Among lymphoproliferative disorders, BRAF mutations are restricted to HCL.

Low-grade fibromyxoid sarcoma of the small intestine: report of 4 cases with molecular cytogenetic confirmation.

Low-grade fibromyxoid sarcoma (LGFMS) is a rare soft tissue tumor that typically involves the deep soft tissues of the extremities. However, LGFMS has been described in other locations including the head and neck, retroperitoneum, and mesentery. Translocations involving the FUS gene located at 16p are considered to be highly specific for the diagnosis of this tumor when present in conjunction with the appropriate morphologic appearance. We report 4 cases of LGFMS arising in the small bowel. The patients' ages (3 female, 1 male) ranged from 52 to 71 years (median, 61 y). None of the patients had a history of soft tissue sarcoma. An intramural tumor was presented in all cases, ranging from 4.5 to 14.5 cm in greatest diameter (mean, 10 cm). Microscopically, the tumors consisted of an admixture of hypocellular, heavily collagenized zones and more cellular myxoid nodules, containing a greater number of neoplastic cells arranged around characteristic curvilinear vessels. By immunohistochemistry, all tumors were positive for vimentin and negative for smooth muscle actin, CD117, CD34, and S100 protein. Fluorescence in situ hybridization for rearrangement of the FUS locus at 16p11 was positive in 3 informative cases. Follow-up information was available in 3 cases; 2 patients are alive without disease and another patient died of disease. We conclude that LGFMS should be included in the differential diagnosis of fibrous or myxoid spindle cell tumors of the gastrointestinal tract. On the basis of limited follow-up, the natural history of enteric LGFMS seems to be similar to that of LGFMS in other locations, with potential for late metastases.

Gastrointestinal stromal tumors: a review of the literature.

Gastrointestinal stromal tumors are mesenchymal neoplasms with a spectrum of histologic appearances and biologic activity. The morphologic classification of these lesions has evolved over time, and molecular analysis has led to a better understanding of their nature. The histologic differential diagnosis for these lesions is broad and includes many spindle cell lesions of the gastrointestinal tract, including neoplasms of true smooth muscle and neural origin, proliferating fibrous lesions, metastatic neoplasms, and primary sarcomas of vascular and adipose origin. Immunohistochemical studies that include CD117 have become invaluable in the classification of mesenchymal lesions arising in the gastrointestinal tract. Treatment of gastrointestinal stromal tumors has historically been involved surgery, but the use of the chemotherapeutic agent imatinib mesylate for advanced disease has made accurate classification even more important. The molecular features have not only allowed us to understand the pathogenesis of these tumors but also have proven to be associated with response to kinase inhibitors.