Review of Hematopathology Consult Cases: A Two-Year Experience in a Tertiary Referral Center in Lebanon.

Hematopathology remains a difficult diagnostic field. With the significant ongoing changes in the classification system that happened over the past several decades, the general pathologist faces many challenges when dealing with patients suspected to have lymphoma or leukemia. The authors assessed referred hematopathology cases that were reviewed by specialized hematopathologists. Of 309 cases, major discrepancy was found in 23% of them. The discrepancy ranged from lymphoma reclassification to other major revisions that had significant impact on patient treatment and management. This paper highlights some of the challenges that may face the general practicing pathologist when dealing with suspected hematopoietic neoplasms.

CD105 (endoglin) is highly overexpressed in a subset of cases of acute myeloid leukemias.

OBJECTIVES: To assess CD105 (endoglin) expression in 119 acute myeloid leukemia (AML) and 13 control cases using immunohistochemistry. METHODS: CD105 expression was assessed retrospectively by using immunohistochemistry in bone marrow specimens. RESULTS: CD105 was strongly and diffusely positive in all 9 (100%) AMLs with t(15;17)(q24.1;q21.2), 2 (100%) AMLs with t(8;21)(q22;q22), 1 (100%) AML with t(6;9)(p23;q34), 7 (28%) of 25 AMLs with myelodysplasia-related changes, 1 (33%) of 3 therapy-related AMLs, 3 (16%) of 19 AMLs unclassifiable, 1 (14%) of 7 AMLs with inv(16)(p13.1q22), and 5 (11%) of 45 AMLs not otherwise specified. Uninvolved bone marrow in these cases showed no CD105 expression by erythroid precursors, megakaryocytes, or endothelial or stromal cells. Two of 13 control bone marrow specimens showed partial CD105 positivity in myeloid cells. In 21 strongly CD105+ AML cases tested for the IDH2 mutation, 9 (42%) were mutated (P = .004). CONCLUSIONS: These data suggest that CD105 could be a therapeutic target in a subset of patients with AML.

Cytarabine, Ki-67, and SOX11 in patients with mantle cell lymphoma receiving rituximab-containing autologous stem cell transplantation during first remission.

BACKGROUND: In the current study, the authors report the results of 39 patients with mantle cell lymphoma (MCL) who were treated with chemotherapy and high-dose rituximab-containing autologous stem cell transplantation (ASCT) during their first disease remission. METHODS: The median age of the patients was 54 years. At the time of diagnosis, 87% of patients had Ann Arbor stage IV disease, and 77% had bone marrow involvement. A Ki-67 level of > 30% was found in 11 of 27 patients (40%), and SOX11 (SRY [sex determining region Y)-box 11] expression was found to be positive in 17 of 18 patients (94%). Twenty-seven patients (69%) underwent induction therapy with high-dose cytarabine-containing chemotherapy. Rituximab was administered during stem cell collection at a dose of 1000 mg/m2 on days +1 and +8 after ASCT. RESULTS: The estimated 4-year overall survival and progression-free survival rates were 82% and 59%, respectively. Twelve patients experienced disease recurrence. Fifteen of 16 patients who were alive and in complete remission at 36 months remained so at a median follow-up of 69 months (range, 38 months-145 months). The only determinant of recurrence risk found was a Ki-67 level of > 30%. Seven of 11 patients with a Ki-67 level > 30% experienced disease recurrence within the first 3 years versus only 3 of 16 patients with a Ki-67 level ≤ 30% (P = .02). Patients who received high-dose cytarabine did not have a significantly different risk of developing disease recurrence compared with other patients (P = .7). CONCLUSIONS: Administering ASCT with rituximab during stem cell collection and immediately after transplantation may induce a continuous long-term disease remission in patients with MCL with a Ki-67 level of ≤ 30%.

Clinicopathologic and immunohistochemical characteristics of male breast cancer: a single center experience.

Male breast cancer (MaleBC) is a rare tumor that has been insufficiently described in the Middle East. The purpose of this study is to report the first MaleBC series in Lebanon, describing its clinicopathologic and immunohistochemical phenotype, and how it compares with MaleBC in the West and with female breast cancer in Lebanon and the Middle East. Forty-seven cases of MaleBC were reviewed. Results showed younger ages at presentation (62 years versus 67 years), higher incidence of lobular carcinoma (6% versus 1%), and more frequent p53 positivity and axillary node metastases in our series than in those reported about MaleBC. Other results such as higher estrogen receptor (ER) positivity and lower HER-2/neu over-expression were comparable to the literature. These findings suggest that MaleBC in our region may represent a biologically different tumor with potentially distinct prognostic and therapeutic implications.

Solid-pseudopapillary neoplasm: a pancreatic enigma.

Solid-pseudopapillary neoplasm of the pancreas is a relatively uncommon tumor. It typically affects young women, has nonspecific clinical and radiologic manifestations, and can be readily diagnosed by ultrasound-guided fine-needle aspiration and histopathologic evaluation. Histologic features characteristically show loosely cohesive, relatively uniform polygonal cells surrounding delicate capillary-sized blood vessels. Other features include cytoplasmic vacuolization, finely stippled chromatin, nuclear grooving, eosinophilic hyaline globules, and degenerative changes. Almost all solid-pseudopapillary neoplasms harbor mutations in the beta-catenin gene. They stain with beta-catenin, CD10, and focally with neuroendocrine markers. Although previously considered benign, this tumor is currently considered a low-grade malignant epithelial neoplasm with low metastatic rate and high overall survival. Most patients are cured by complete surgical excision. Despite the characterization of the morphologic and molecular features of this enigmatic neoplasm, more work is needed to uncover its cell of origin and true histogenesis.

Solitary mediastinal lymph node metastasis in rectosigmoid carcinoma: a case report.

INTRODUCTION: Colorectal cancer most commonly metastasizes to the regional lymph nodes, liver, bone, lung, and brain. Metastases to mediastinal lymph nodes is a rare entity which has never been reported to be solitary. CASE REPORT: We herein describe a 67-year-old male patient with a solitary mediastinal lymph node metastasis three years following the resection of his primary rectosigmoid carcinoma. Pathological characteristics of the metastatic tissue and technical limitations in imaging modalities resulted in incongruity between follow-up CT and PET scans. Diagnosis of this distant metastasis has been confirmed through a mediastinoscopic biopsy. CONCLUSION: Attention should be paid to the mediastinum when evaluating PET scan or CT films during follow-up of patients with colorectal cancer. Using PET/CT instead of separate morphological and functional data sets favors better detection. Questions still remain concerning the ideal management protocol of such a presentation, the two main options being locoregional or chemotherapeutic.