Warthin-Finkeldey polykaryocytes demonstrate a T-cell immunophenotype

Delay in the diagnosis of measles complicated by pneumonitis and appendicitis in a returning traveller

A 40-year-old British man presented to the emergency department for the second time in 10 days following a 2-week holiday in Thailand with malaise, bilateral conjunctivitis and a morbilliform rash. He had previously seen his general practitioner and ophthalmology and was diagnosed with conjunctivitis. We confirmed measles following RNA detection on a mouth swab. Four days after admission he developed abdominal pain and a CT abdomen demonstrated acute appendicitis with large appendicoliths. A perforated appendix was identified intraoperatively. Measles RNA was detected in the resected appendix. Preoperatively he developed hypoxia with right upper lobe changes seen on a CT pulmonary angiogram. Bronchoalveolar lavage performed in theatre isolated measles RNA at high level, consistent with measles pneumonitis. He required ventilatory support in the intensive care unit and was also treated with intravenous antibiotics. He made a complete recovery.

Mulberry cells in the thyroid: warthin-finkeldey-like cells in hashimoto thyroiditis-associated lymphoma

Warthin-Finkeldey type giant cells were first described in autopsies performed on young children who died during the highly lethal measles epidemic in Palermo during the winter of 1908. The cells had 8-15 nuclei without identifiable cytoplasm within the germinal centers of lymphoid organs resembling megakaryocytes. We describe a case of Hashimoto thyroiditis with an enlarging substernal throid mass. The resection specimen contained many Warthin-Finkeldey-Like Cells (WFLC) in an extranodal marginal zone lymphoma (MALT type) with focal transformation to diffuse large B-cell lymphoma. The WFLC showed nuclear features similar to those of neighboring follicular dendritic cells (FDCs), favoring the hypothesis that these cells might be the product of fusion of FDCs. This is supported by immunostaining results and the occurrence of similar cells in follicular dendritic cell sarcomas and in "dysplastic" FDCs in hyaline vascular type Castleman disease, a possible precursor of follicular dendritic cell tumors. Diagn. Cytopathol. 2017;45:212-216. © 2016 Wiley Periodicals, Inc.

Reactive lymphadenopathy in Ugandan patients and its relationship to EBV and HIV infection

In Uganda, a large number of biopsied enlarged lymph nodes is diagnosed as reactive lymphoid hyperplasia (RLH) not indicative of a specific etiologic agent. The aim of this study was to examine the spectrum of RLH in lymph node biopsies in Ugandan patients and their possible association with HIV and EBV infection. Ninety biopsies were retrieved and included in the study. The predominant RLH type was follicular, found in 45 (50.0%) of the cases. Positive staining for LMP-1 was found in six cases (6.7%), EBNA-1 in 36 cases (40.0%) and HIV1-p24 in 15 cases (16.7%), respectively. A combination of EBV and HIV positivity was found in 46 (52.2%) of the cases. EBV infection was associated with hyperplastic germinal centers (p<0.01). HIV1-p24 positive staining was associated with follicle fragmentation (p<0.01) but not hyperplastic GC (p=0.08). In conclusion, RLH in Ugandan patients is frequently associated with EBV and HIV infection. The histologic features of the lymph nodes are not specific for any individual infection, but a high number of EBV-positive cases are associated with hyperplastic GC, and follicular fragmentation is characteristic of HIV infection.

The Warthin-Finkeldey-type giant cell in HIV infection, what is it?

A study was conducted to ascertain the origin of the Warthin-Finkeldey-type giant cell that is common to lymphoid tissues of HIV-infected individuals. Light microscopy (LM) and transmission electron microscopy (TEM), in situ hybridization (ISH) (HIV-specific RNA), and immunohistochemistry (HIV p24, OPD4, CD3, CD45 UCHL, CD21, CD35, S-100, p55 (actin-bundling protein), CD68, HAM56, alpha-1-antitrypsin, alpha-1-antichymotrypsin, and lysozyme) studies were performed on hyperplastic tonsil, adenoid, lymph node, and intestinal MALT specimens from HIV+ patients. Warthin-Finkeldey-type giant cells (WFTGC) and follicular dendritic cells (FDC) shared characteristic morphologic (high N: C ratio; crowded, irregular nuclei; thin filaments with dense bodies; desmosomes; and cilia) and immunophenotypic (CD21+, CD35+, S-100+, p55, and vimentin+) features. Also, transitional forms between binucleated FDC and WFTGC were identified by TEM. TEM and ISH revealed evidence of HIV expression by FDC, but not WFTGC. WFTGC in HIV- lymphoid specimens displayed identical LM and IHC characteristics. The WFTGC in HIV infection appears to represent a multinucleated form of FDC.

Angiomyoid and follicular dendritic cell proliferative lesions in Castleman's disease of hyaline-vascular type: a study of 10 cases

Castleman's disease of hyaline-vascular type (HV CD) may rarely be associated with a confusing variety of stromal cell overgrowths and neoplasms. We report here on the pathologic and clinical findings of 10 such cases. In addition to the usual complex histoimmunophenotype of the stroma of HV CD and some unusual features that mimicked neoplasms, we observed focal proliferations of angiomyoid (five cases) and follicular dendritic cell type (five cases). The former were nonneoplastic growths featuring compact tangles of spindle cells, exhibiting immunoreactivity for smooth muscle actin and interpreted as vessel-related pericytes and myoid cells. The latter were neoplastic growths of oval to spindle cells intermixed with lymphocytes; the tumor cells grew in long, intersecting bundles, featured various degree of atypia, and expressed the markers of follicular dendritic cells (CD21, CD35, KiM4p). The two types were clinically distinct. Four of five patients with angiomyoid proliferations were young women, who presented with an abdominal mass and were cured by surgery; that is, they had a clinical profile similar to that of patients with the stroma-rich variant of HV CD. The follicular dendritic cell proliferations were in older patients of either gender presenting with masses at various sites, recapitulating the profile of follicular dendritic cell tumors arising independently from HV CD; in three patients with long-term follow-up, recurrences or metastases developed at various intervals from the initial diagnosis (1 1/6, 3 1/2, and 11 years), and one patient died as a result. This study confirms the potential for, and the variety of, stromal cell proliferations in HV CD. Because their biologic behavior differs, correct identification of these various proliferative lesions is clinically important.

Pathogenesis of porcine reproductive and respiratory syndrome virus infection in gnotobiotic pigs

The pathogenesis of porcine reproductive and respiratory syndrome virus (PRRSV) was determined in gnotobiotic pigs by studying the sequential development of microscopic lesions and sites of virus distribution and replication. Thirty-two pigs (three pigs/infected group and one pig/control group) were inoculated by nasal instillation of either PRRSV isolate ATCC VR-2332 (total dose 10(2.6) TCID50) or uninfected cell culture supernatant. Infected and control pigs were euthanized at 12 hours, and 1, 2, 3, 5, 7, 14, and 21 days postexposure (PE). Gnotobiotic pigs experimentally infected with PRRSV were viremic by 12 hours PE and subsequently developed pneumonia, lymphadenopathy, vasculitis, myocarditis and encephalitis. Lung lesions developed by day 3 PE, persisted through day 21 PE and were characterized by alveolar septa thickened by macrophages, alveolar proteinaceous and karyorrhectic debris, alveolar syncytial cells, and multifocal type II pneumocyte hypertrophy. Lymph node lesions varied in distribution and severity and were characterized by germinal center hypertrophy and hyperplasia, lymphocyte necrosis, multiple cystic spaces, and polykaryocytes within the cystic spaces. Heart lesions were a late feature of infection and all infected pigs had heart lesions on day 21 PE characterized by subendocardial, myocardial, and perivascular foci of lymphocytes. Vasculitis also varied in distribution and severity and affected all sizes of vessels. Results of this experiment indicate that PRRSV is a multisystem disease characterized initially by viremia with subsequent virus distribution and replication in multiple organs causing interstitial pneumonia, vasculitis, lymphadenopathy, myocarditis, and encephalitis.

Systemic lymphadenopathic histology in human immunodeficiency virus-1-seropositive drug addicts without apparent acquired immunodeficiency syndrome

We examined lymph nodes from multiple sites in 50 individuals infected with human immunodeficiency virus (HIV-1) who died accidentally of drug overdoses and in whom there was no evidence of opportunistic infection. The size, histologic pattern, presence of Warthin-Finkeldey-type giant cells, and estimation of CD4 cell count of these lymph nodes were compared with those of 13 seronegative drug addicts (controls). Lymph nodes from seropositive individuals were slightly but significantly larger than those of controls. Lymph nodes from seropositive cases were much more likely to contain secondary follicles (90%) than were those from controls (20%). Unlike follicles in control nodes, most secondary follicles in the seropositive cases were in various stages of fragmentation and involution. As follicular changes progressed, there was a decrease in CD4 cells and an increase in intrafollicular and paracortical plasma cells. Plasmacytosis was much more prevalent in lymph nodes from seropositive individuals than in controls. Warthin-Finkeldey-type giant cells were present in at least one node in 29 of 50 seropositive cases, were most numerous in those showing follicular hyperplasia with fragmentation (45% of cases), and were especially numerous in Peyer's patches (61% of cases). There was generally good concordance of HIV-1-associated follicular morphology among diverse lymph node groups. There is prolonged generalized, mild hyperplastic lymphadenopathy with frequent syncytial cells in intravenous drug addicts with asymptomatic HIV-1 infection.

Rectal mucosal pathology varies with human immunodeficiency virus antigen content and disease stage

Rectal mucosal biopsy specimens from 75 human immunodeficiency virus (HIV)-seropositive and 16 HIV-seronegative subjects were examined. The histopathologic changes were correlated with immunoperoxidase staining for UCHL-1 and HIV core protein p24, quantitative p24 enzyme-linked immunosorbent assay (ELISA) assay in homogenized rectal tissue and serum, and a modified Walter Reed clinical stage. Four phases were seen in the HIV-infected subjects: (1) early phase, in Walter Reed stage 1-2 subjects, with nearly normal histology and low p24; (2) inflammatory phase, typically in Walter Reed stage 3-4 subjects, with a superficial lamina propria infiltrate of lymphocytes, plasma cells, and eosinophils with degranulation, abundant UCHL-1 staining, and maximal p24 by both immunoperoxidase staining and ELISA; (3) transitional phase, in many Walter Reed 5 and some Walter Reed 6 subjects, with normal lymphocyte population density but with subtle inflammatory changes; and (4) lymphoid depletion phase, mainly in Walter Reed stage 6 subjects, with decreased lymphocytes but often with endothelial cell activation and apoptosis. These phases presumably result from effective HIV suppression by a relatively intact immune system, followed by maximal HIV infection and lymphocyte activation, then progressive lymphocyte depletion. The inflammation correlated with the presence and amount of HIV in rectal tissue determined by immunohistochemistry and ELISA and was maximal before overt immunodeficiency developed. Intestinal mucosa could be a preferred site of HIV proliferation and T-cell destruction.