Immunohistochemical characterization of estrogen and progesterone receptors in lymphoma of horses

Occurrence of lymphoma in non-gonadal organ during pregnancy: a report on four cases and literature review

Lymphoma rarely occurs during pregnancy, making this condition difficult to define. Lymphomas that occur in reproductive organs during pregnancy exhibit unique clinical characteristics. Among the limited cases, non-Hodgkin's lymphoma (NHL) shows a considerably higher incidence rate than Hodgkin's lymphoma (HL); NHL also displays clinical characteristics, such as high aggressiveness, advanced stage, and poor outcome. This study reports on four cases of lymphomas in non-gonadal organs (HL, n=2; NHL, n=2) during pregnancy. The tumors rapidly progressed in all patients during pregnancy but remitted at the end of pregnancy and/or therapy. The two HL cases were nodular sclerosis classical HL and treated with chemotherapy after terminating the pregnancy. One of the NHL cases was primary cutaneous follicular center lymphoma, a B cell-derived indolent lymphoma. The patient was followed up without any therapy after terminating her pregnancy. The other case was a follicular lymphoma grade 3B, which was treated with chemotherapy after delivery. We also conducted a literature review of 165 lymphoma cases occurring during pregnancy reported from 1976 to 2013 to reveal the correlation between pregnancy and lymphoma progression. Immunohistochemistry studies were performed to determine the expression of estrogen/progesterone receptors (ER/PR), and ER was weakly positive and sporadic. We concluded that lymphomas occurring during pregnancy should be managed with a prompt and reasonable treatment. High estrogen level in maternal body may affect lymphoma progression.

Clinical, Laboratory, and Histopathologic Features of Equine Lymphoma

Clinical, laboratory and tissue findings from 37 horses with lymphoma were investigated. Horses ranged in age from 0.3 to 20.5 years (median 5.0 years) and included 18 females and 19 males. Weight loss ( n = 25) and ventral edema ( n = 21) were the most common historical and physical abnormalities. The most common laboratory abnormalities were hyperfibrinogenemia ( n = 26), hypoalbuminemia ( n = 19), anemia ( n = 19), leukemia ( n = 14), hyperglobulinemia ( n = 13), and thrombocytopenia ( n = 13). Thirty-four tumors involved multiple lymphoid tissues and abdominal or thoracic organs, and 3 tumors were restricted to cutaneous and subcutaneous sites. Histopathologically, all tumors diffusely effaced normal lymph node architecture. Tumor cell morphology was heterogeneous in 17 tumors, and 8 tumors had marked histiocytic and multinucleated giant cell infiltrates. Extensive necrosis or focal fibrosis was present in 22 and 4 lymphomas, respectively. Staining of tumor sections with antibodies against CD3 and CD79α molecules resulted in classification of T-cell ( n = 26) or B-cell ( n = 7) origin. Four tumors could not be classified. Most T-cell tumors comprised small to medium CD3+ lymphocytes, whereas 5 of 7 B-cell tumors were infiltrated by numerous small T lymphocytes and classified as T-cell-rich B-cell lymphoma. Neither estrogen nor progesterone receptor expression was consistently identified by immunochemical assessment of tumor tissues. Fresh tumor cells from 6 horses bound antibodies reactive with equine CD4, CD5, CD8, CD21, or major histocompatibility class II molecules, confirming T-cell ( n = 5) or B-cell origin ( n = 1). These findings suggest that T-cell lymphoma is more common than B-cell lymphoma in horses and that inflammation, possibly from tumor cytokine production, is frequent.

Two Hundred Three Cases of Equine Lymphoma Classified According to the World Health Organization (WHO) Classification Criteria

Lymphoma is the most common malignant neoplasm in the horse. Single case reports and small retrospective studies of equine lymphomas are reported infrequently in the literature. A wide range of clinical presentations, tumor subtypes, and outcomes have been described, and the diversity of the results demonstrates the need to better define lymphomas in horses. As part of an initiative of the Veterinary Cooperative Oncology Group, 203 cases of equine lymphoma have been gathered from 8 institutions. Hematoxylin and eosin slides from each case were reviewed and 187 cases were immunophenotyped and categorized according to the World Health Organization classification system. Data regarding signalment, clinical presentation, and tumor topography were also examined. Ages ranged from 2 months to 31 years (mean, 10.7 years). Twenty-four breeds were represented; Quarterhorses were the most common breed ( n = 55), followed by Thoroughbreds ( n = 33) and Standardbreds ( n = 30). Lymphomas were categorized into 13 anatomic sites. Multicentric lymphomas were common ( n = 83), as were skin ( n = 38) and gastrointestinal tract ( n = 24). A total of 14 lymphoma subtypes were identified. T-cell–rich large B-cell lymphomas were the most common subtype, diagnosed in 87 horses. Peripheral T-cell lymphomas ( n = 45) and diffuse large B-cell lymphomas ( n = 26) were also frequently diagnosed.