Natural killer cell malignancy associated with Epstein-Barr virus and hemophagocytic syndrome.

Natural killer cell malignancy is a rare and aggressive lymphoid neoplasm encompassing extra-nodal NK/T-cell lymphoma, nasal-type (ENKLN) and aggressive NK-cell lymphoma/leukemia (ANKL). A case of cutaneous ENKLN and a case of ANKL in Thai patients are reported Both patients developed hemophagocytic syndrome and shortly succumbed to death. The cells in cutaneous ENKLN are small to medium in size with minimal cytoplasm, round nuclei, irregular nuclear membrane, andfine chromatin with inconspicuous nucleoli. While that of ANKL are medium to large-sized mononuclear cells with moderate cytoplasm. Their nuclei are elongated to embryo-like with irregularly thickened nuclear membrane, fine chromatin, and small to occasional prominent nucleolus. Ancillary techniques studied on paraffin embedded tissues of both cases demonstrated that the neoplastic cells exhibit cytoplasmic CD3+, CD56+ and cytotoxic granules + by immunohistochemistry, absence of T cell receptor gene rearrangement by PCR, and presence of Epstein-Barr virus mRNA (EBER) transcripts by in situ hybridization. The authors reviewed the literature on natural killer cell neoplasm and compared the clinical characteristics, natural history, and association of Epstein-Barr virus infection with hemophagocytic syndrome.

Isospora belli infection associated with chronic cholecystitis and sclerosing cholangitis in immuncompetent host : A case report.

Isospora belli (I. belli) is a spore-forming protozoa that primarily infects enterocyte. The clinical manifestation may very from asmptomatic to self-limited diarrhea in healthy persons. Rarely, in the normal hosts,5 chronic persistent or intermittent symptom may continue for many years.1,2 Treatment with cotrimoxazole is usually effective in both normal patients19 and patients with AIDS20,21 Nevertheless, relapse is common and is believed to be associated with the presence of extraintestinal infection.3,4,17 Few cases of extraintestinal I. belli infection have been documented in patients with AIDS,3-5 and one case in an immuncompetent patient.24 This report presents a unique case of isosporiasis in a 58-year-old anti-HIV negative Thai female suffering from chronic recurrent diarrhea due to I. belli, despite two episodes of complete 4-week cotrimoxazole and another course of nitazoxanide. Abdominal computer tomographic examination and ultrasonography identified sclerosing cholangitis and chronic cholecstitis. Histologic examination of the cholecystectomy specimen recovered schizonts and merozoites in the parasitophorous vacuoles located in gallbladder epithelium.

Two unusal primary carcinomas of the glans penis: Mucoepidermoid carcinoma and adenosquamous carcinoma.

Two cases of rare histologic subtypes of carcinomas involving glans penis are reported. Both contained two distinct cellular differentiation, squamous cells and mucin-producing cells. The first case was a 34-year-old Thai male with chronic ulcer at penis, showing predominant squamous cell carcinoma with interspersed small sheets of mucin-producing cells without discrete glandular structure, thus designated as “muco-epidermoid carcinoma”. The involved inguinal lymph node revealed both squamous and mucin-producing cells. Another case is a 39-year-old Thai male with penile, histologicaly proved to be carcinoma mainly constituted by malignant sqlignant part and focal glandular differentiation. The glands lined by colummer cells contained intraluminal and intracellular mucin. The bilateral sentinel lymph nodes were negative for malignancy. The immunoperoxidase staining for carcinoembryonic antigen was positively marked with mucin-producing cells in both cases. In addition, transmission electron microscopic study of mucoepidermoid carcinoma identified three populations of cells, namely squamous cells with tonofilament, mucin-producing cells with microvilli, and lastly intermediate cells bearing dual differentiation. These unusual carcinoma of glans penis are extremely rare conditions of unknown origin with a poorly defined prognosis. Discussion and review literature on the histologic definition and origin of these tumors are included.