Quantification of eosinophils in the lower gastrointestinal tract of adults: a review of surgical specimens with normal histology from the Free State province, South Africa

AIM

Eosinophils are normal residents of the gastrointestinal tract (GIT). They are noted in small numbers with significant variation between anatomic locations. An idiopathic increase of eosinophils is known as eosinophilic gastrointestinal disease (EGID). EGIDs are a heterologous group of disorders that produce a range of enteric and colonic syndromes. Their incidence has been increasing worldwide. Our study aimed to quantify eosinophils in each segment of the GIT in surgical specimens with normal histology to facilitate the histological diagnosis of EGID. Similarly, we aimed to describe the effect of race and gender on gastrointestinal eosinophil numbers.

METHODS

A retrospective, quantitative comparative study was performed. We assessed 360 surgical specimens with normal histology from the lower gastrointestinal tract of African and Caucasian adults from the Free State Province, South Africa. The number of eosinophils per mm² was counted.

RESULTS

Overall, comparable eosinophil values were noted for both males and females, and African and Caucasian South Africans. However, Caucasians recorded a higher concentration of eosinophils in the appendix and the left colon. Eosinophils were most numerous in the lamina propria, with only small numbers present in the epithelium. Our results show that the South African population has similar eosinophil distribution trends to international studies. However, South Africans had far fewer eosinophils than Japanese and North American adults in each segment.

CONCLUSIONS

Specific eosinophil reference ranges were formulated to quantify reference ranges of eosinophils in the lower GIT, allowing for the accurate diagnosis of EGIDs in our population in future.

Epstein-Barr virus reactivation influences clonal evolution in human herpesvirus-8-related lymphoproliferative disorders

Background

Human herpesvirus‐8 (HHV8) is a lymphotropic virus associated with different lymphoproliferative disorders, including primary effusion lymphoma (PEL), multicentric Castleman’s disease (MCD), diffuse large B‐cell lymphomas, not otherwise specified, and the rare entity known as germinotropic lymphoproliferative disorder (GLPD). In PELs and GLPD the neoplastic cells also contain Epstein–Barr virus (EBV). In addition, occasional cases with atypical and overlapping features among these entities have been recognised, suggesting that the spectrum of the HHV8‐related lesions may not be fully characterised.

Aims

Here, we report two cases of lymphoproliferative disorder associated with HHV8 and EBV that further expand the spectrum of HHV8/EBV‐positive lymphoproliferative disease.

Methods and results

Case 1 represented HHV8/EBV‐positive extracavitary nodal PEL followed by pleural PEL. The striking characteristic of this case was the almost focal and intrasinusoidal localisation of the neoplastic cells and the association with Castleman’s disease features. In the second case, we found the entire spectrum of HHV8‐related disorders, i.e. MCD, GLPD, and PEL, coexisting in the same lymph node, underlining the variability, possible overlap and evolution among these entities. Both cases were well analysed with immunohistochemistry, determination of the EBV latency programme, and molecular analysis for clonality of immnoglobulin genes. In both patients, the disease followed an unexpected indolent course, both being still alive after 8 and 12 months, respectively.

Conclusion

Our findings represent further evidence of the overlap among HHV8/EBV‐positive lymphoproliferative disorders, and underline a grey zone that requires further study; they further confirm the experimental evidence that lytic EBV replication influences HHV8‐related tumorigenesis.

Human papillomavirus DNA in head and neck squamous cell carcinomas in the Free State, South Africa

Human papillomaviruses (HPVs) have been associated with a subset of head and neck squamous cell carcinomas (HNSCCs). The aim of this study was to determine the prevalence of HPV DNA in archived formalin-fixed paraffin-embedded tissue from patients with histologically confirmed HNSCCs in a South African cohort. A nested PCR was used for the detection of HPV DNA targeting the L1 gene. Positive samples were confirmed using an in-house hemi-nested PCR targeting the E6 gene and genotyped by sequence determination of amplicons. HPV DNA was detected in 57/780 (7.3%) samples, with the highest prevalence being in the sinonasal tract (16.0%) and oropharynx (10.8%). HPV16 was the most frequently detected type, being found in 26/57 (45.6%) positive samples. The prevalence of HPV DNA in HNSCCs found in this study was lower than that found in developed countries.

Persistence of Crimean-Congo Hemorrhagic Fever Virus RNA

Crimean-Congo hemorrhagic fever virus (CCHFV) causes severe disease with fatalities. Awareness of potential sources of infection is important to reduce risk to healthcare workers and contacts. We detected CCHFV RNA in formalin-fixed, paraffin-embedded tissues from a spontaneous abortion that were submitted for histology 9 weeks after a suspected CCHFV infection in the mother.

Human immunodeficiency virus (HIV) infection in men with penile carcinoma is associated with increased prevalence of human papilloma virus infection and younger age at presentation

BACKGROUND

We investigated the prevalence of HIV and human papilloma virus (HPV) infection in men with penile carcinoma.

METHODS

This retrospective study investigated all men with penile carcinoma at the Universitas Academic Hospital in Bloemfontein, South Africa (January 2000-December 2008). Patients' age, HIV status, histological type of carcinoma and evidence of HPV infection were recorded. Statistical analyses included Student's t-test and Fisher's exact test where appropriate (2-tailed p-value < 0.05 indicated statistical significant).

RESULTS

Among 65 patients (mean age 50.9 years, range 37-69), the most common histological type was squamous cell carcinoma (80.0%). HIV status was known for 48 patients; 27 (56.2%) were HIV-positive. The mean age at presentation was 43.7 years (range 26-69) years in the HIV-positive and 57.2 years (range 26-89) years in the HIV-negative group. Approximately 55% of HIV-positive and 24% of HIV-negative patients showed histological evidence of HPV infection (p = 0.04). No significant difference was found with regard to histological type of carcinoma.

CONCLUSION

Patients with penile carcinoma had a high prevalence of HIV infection. The HIV-positive group were significantly younger at presentation, with a higher prevalence of HPV infection, suggesting that HIV may contribute to HPV-associated penile cancer at a younger age.

Primary pulmonary lymphoepithelioma-like carcinoma in a 12-year-old African child

Pulmonary lymphoepithelioma-like carcinoma is a rare malignant tumour predominantly occurring in Asian patients. It has identical histological features to nasopharyngeal carcinoma. To date, Epstein–Barr virus (EBV) in pulmonary lymphoepithelioma-like carcinoma has been limited to the Asian population. This manuscript presents an unusual case in a 12-year-old African boy in which the tumour tested positive for EBV.

Chronic lymphocytic leukaemia with concomitant plasmablastic lymphoma

Plasmablastic lymphomas are high-grade lymphomas that usually occur in immune-suppressed patients. Occasionally, they can arise from an underlying haematolymphoid malignancy, termed ‘transformed plasmablastic lymphoma’. In this report, we describe a case of chronic lymphocytic leukaemia and plasmablastic lymphoma in an elderly HIV-negative patient.

A histopathological study of melanocytic and pigmented skin lesions in patients with albinism

BACKGROUND

Oculocutaneous albinism (OCA) is a group of genetic disorders characterized by diminished pigmentation of the skin, hair and eyes. Individuals with OCA are at increased risk to develop sun-induced skin malignancies. The incidence of malignant melanoma in OCA individuals is, however, very low. The aim of this study was to document pigmented and melanocytic skin lesions occurring in patients with OCA.

METHODS

A prospective study was performed. Sixteen patients with OCA presenting at the Oncology and Dermatology Departments at Universitas Academic Hospital Annex in Bloemfontein, South Africa, were included. Selected clinically pigmented and/or melanocytic lesions were biopsied and studied by light microscopy.

RESULTS

Twenty-four punch biopsies were taken. Ten dendritic freckles and 10 melanocytic nevi were confirmed histologically. The nevi, which occurred in eight patients, were found on sun-protected skin. All the freckles occurred on sun-exposed skin. Twelve patients had current or previous skin malignancies. No melanomas were present in the study population. Other skin lesions ranged from solar keratoses to squamous cell carcinomas.

CONCLUSION

The majority of pigmented lesions were dendritic freckles that occurred on sun-exposed skin. None of the patients had a current or previous diagnosis of malignant melanoma.

Molecular characterisation of gastrointestinal stromal tumours in a South African population

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the digestive tract. Pathogenesis is linked to activating mutations identified in two proto-oncogenes, v-kit Hardy/Zuckerman 4 feline sarcoma viral oncogene homologue KIT (KIT) and the platelet-derived growth factor α (PDGFRα). In addition, these mutations affect response to treatment with tyrosine kinase inhibitors. In the present study, we report on the molecular characterisation of GISTs in the South African population. Tumour DNA was extracted from 46 GIST samples, followed by cycle sequencing of KIT exons 11, 13 and 17 and PDGFRα exons 12, 14 and 18. Fragment length analysis was used to detect a 6-bp duplication in KIT exon 9. Wild-type duplications were analysed further by PCR and sequencing of additional KIT and PDGFRα exons was performed. Overall, 78.3% of the samples had a mutation in KIT or PDGFRα. Of these, mutations were detected in KIT exon 11 (88.9%), PDGFRα exon 18 (8.3%) and KIT exon 9 (2.8%). Mutations varied from simple substitutions and duplications to large deletions (some with nucleotide insertions) resulting in missense mutations. In addition, seven single nucleotide polymorphisms were detected in 17 patients, one of which appears novel. The incidence of mutations in KIT exon 11 and PDGFRα exon 18 is consistent with the literature, however, the low incidence of KIT exon 9 mutations detected was unexpected. In contrast to previous western and Asian studies, this mutation appears to be rare in the South African population. The present study contributes to the molecular understanding of GISTs in the South African population.

Malignant Mesothelioma with Intracytoplasmic Crystalline Inclusions

A 60-year-old female presented with a history of hoarseness, cough, chest pain, and dyspnea and a needle biopsy sample was submitted for histology. Light microscopy showed sheets of tumor cells with eosinophilic cytoplasm containing multiple crystals and eccentrically located nuclei. Electron microscopy showed large intracytoplasmic crystalloid inclusions. No crystalloid structures were found extracellularly. The tumor cells also had long slender microvilli and cell junctions, the features being consistent with a malignant epithelial mesothelioma. In the authors' experience this is a rare finding. The clinical information initially received was poor and electron microscopy was essential in making the correct diagnosis.

The Ultrastructural Features of Plasmablastic Lymphoma

Plasmablastic lymphoma was originally described in 1997 by Delecluse et al. and is an aggressive variant of diffuse large B-cell non-Hodgkin lymphoma seen predominantly in a setting of acquired immunodeficiency syndrome and nearly always in extranodal sites. The authors have seen 10 cases in their department between 2001 and 2005. The patients' ages ranged from 24 to 39 years and there were 7 females and 3 males. In 7 cases where human immunodeficiency virus had been tested it was positive. Eight cases were extranodal and 2 cases involved lymph nodes. Five cases were followed up and 4 were confirmed dead within 5 months of diagnosis, verifying the aggressive nature of this condition. Histology showed large, polygonal tumor cells some of which had a slightly plasmacytic appearance. Six cases had a "starry sky" background. Immunohistochemical stains were negative in 1 case, while the other 9 cases were positive for CD138. Electron microscopy showed concentrically arranged rough endoplasmic reticulum in the cytoplasm in 9 cases. In 1 case the cells were too degenerate for evaluation. This study shows that the ultrastructural features are well developed and can help in distinguishing plasmablastic lymphoma from other light microscopically undifferentiated tumors.