Microfilariae in lymph node aspirate associated with metastatic gastric carcinoma: a case report.

BACKGROUND: Microfilariae of Wuchereria bancrofti inhabit peripheral blood, and nocturnal periodicity is observed in the Indian subcontinent. However, microfilariae have been reported in various tissues and organs by needle aspiration cytology in atypical cases. Occasionally, they were detected in cases with some diseases including malignancy. CASE: A 55-year-old man presented with complaints of weakness, abdominal distention and anorexia for 3 months. He had pain in the upper abdomen, passage of blackish stool and an episode of hemoptysis later on. A provisional diagnosis of gastric carcinoma with cirrhosis and ascites was made. Aspiration cytology of the left supraclavicular lymph node revealed a microfilaria in the background of malignant cells. Biopsy of the antral mass confirmed the diagnosis of gastric carcinoma. CONCLUSION: Detection of a microfilaria with malignant cells in the lymph node aspirates in a case of gastric carcinoma as an incidental finding is being reported for the first time. It may be due to its transmigration along with metastatic emboli in an immunosuppressed state.

Molecular evidence for apoptosis in microfilariae of Wuchereria bancrofti induced by diethylcarbamazine.

Apoptosis, a programmed cell death, is characterized by chromatin condensation, numerous vacuoles, reduction in cell volume, and endonuclease cleavage DNA degradation detected in gel electrophoresis as nucleosomal ladder. Here we report that diethylcarbamazine induces DNA fragmentation in microfilariae of Wuchereria bancrofti revealed by ligation-mediated polymerase chain reaction and by in situ terminal deoxynucleotidyl transferase-mediated dUTP nick end-labeling at the light and electron transmission level.

Cytodiagnosis of filarial infections from an endemic area.

OBJECTIVE: To throw light on cytologic findings as a possible mode of diagnosis of lymphatic filariasis. STUDY DESIGN: Filariasis has worldwide distribution, but lymphatic filariasis predominantly affects tropical and subtropical regions. Demonstration of microfilaremia, the specific test for diagnosis of lymphatic filariasis, often shows false negative results in endemic areas. The present study, done in an endemic area, showed the presence of microfilariae or adult worms of Wuchereria bancrofti in fine needle aspirates collected from amicrofilariaemic cases. In a few cases the discovery was incidental. A total 4,534 cases undergoing cytologic evaluation were carefully screened for the presence of adult worms or larvae, irrespective of clinical diagnosis. Microfilariae were demonstrated in both clinically suspected cases of filariasis and asymptomatic cases. RESULTS: A total of 1 positive cases were found; in 4 cases the clinical diagnosis was lymphatic filariasis, and 7 cases were asymptomatic. All 11 cases were amicrofilariaemic. CONCLUSION: Various sophisticated investigations are used for diagnosis of lymphatic filariasis without microfilaremia. Fine needle aspiration cytology, being a cheap, simple and easy procedure, may have some role in this field, but further detailed studies are needed before any final claim.

Incidental detection of microfilariae in aspirates from Ewing's sarcoma of bone.

Microfilariae have been reported as coincidental findings with various neoplasms. We present a case in which microfilariae were encountered in fine-needle aspiration (FNA) smears from a 10-yr-old boy who presented with a lytic lesion in the diaphysis of the right tibial bone. Stained aspirates from the swelling were composed of a dispersed population of small round cells with scanty to vacuolated cytoplasm. Two sheathed microfilariae with several nuclei and cephalic and caudal clearing were identified. A diagnosis of Ewing's sarcoma with presence of microfilariae of Wuchereria bancrofti was made. The diagnosis of Ewing's sarcoma was confirmed on histopathology.

Diagnosis of microfilaria in gastric brush cytology. A case report.

BACKGROUND: Filariasis due to Wuchereria bancrofti is endemic to southern Asia. While the laboratory diagnosis has been conventionally made by demonstrating microfilariae in peripheral blood smears, these have also been occasionally diagnosed on aspiration cytology of various organs. CASE: A 54-year-old male presented with a burning sensation in the epigastrium of five months' duration. Endoscopic brush biopsy revealed numerous sheathed microfilariae of W bancrofti. The patient had had no symptoms suggestive of filarial infection in the past. Cytology revealed numerous microfilariae among lymphocytes and neutrophils. CONCLUSION: This case illustrates that a thorough examination of gastric brushings can at times reveal unexpected findings and may prove to be a useful supplement to endoscopic biopsy.

Temperature thresholds and statistical modelling of larval Wuchereria bancrofti (Filariidea:Onchocercidae) developmental rates.

Developmental rates for Wuchereria bancrofti larvae maturing in the vector Aedes polynesiensis were estimated by analysing stage-frequency data consisting of counts of larval stages in mosquitoes reared at 20, 22.5, 25, 27.5, 30 and 32 degrees C. Base temperatures (i.e. low temperature thresholds) for W. bancrofti development were estimated by the x-intercept method and the model of Lactin et al. (1995). Resulting values were similar with both methods and were approximately 12.5 degrees C for microfilariae (mf) in thorax, approximately 17 degrees C for L1, 15.5 degrees C for L2 and 16.5 degrees C for L3. Upper thresholds estimated by the Lactin et al. model were 29.3 degrees C for mf, 29.1 degrees C for L1, 32.2 degrees C for L2 and 31.5 degrees C for L3. In addition, an original method was devised for computing the L3 upper threshold, by modelling L3 length shrinkage with temperature. It gave a value of 31.4 degrees C. At 32 degrees C, L2 and L3 stages exhibited altered morphology, larvae being shorter and wider than expected. The model of Lactin et al. described adequately the non-linear relationship between developmental rate and temperature, but a linear degree-day approach may be applied for temperatures below 27-28 degrees C.

Nodular breast filariasis: diagnosis by fine needle aspiration.

Bancroftian filariasis is a tropical disease transmitted by mosquitoes that most often causes lymphadenitis. This article reports on a breast nodule due to Wuchereria bancrofti in a woman living in New Caledonia. The diagnosis was done by fine needle aspiration, which showed several microfilariae and avoided surgical treatment.

Fine structure and localization of anionic sites on the surface of microfilaria of Wuchereria bancrofti.

The fine structure of the sheath and the cuticle of microfilaria of Wuchereria bancrofti was analysed and the results obtained were compared with those from other filarial parasites. Cationized ferritin particles bind to the surface of the sheath and the epicuticle. No binding of colloidal iron hydroxyde particles to the microfilaria surface was observed. Reaction product indicative of carbohydrates containing vic-glycol groups was not observed in thin sections of microfilaria submitted to the periodic acid-thiosemicarbazide-silver proteinate technique. The results obtained are discussed in relation to previous studies using lectins.

Microfilariae of Wuchereria bancrofti in cytologic smears.

Microfilariae of Wuchereria bancrofti were observed in cytologic material in 35 cases. The material included cervicovaginal smears (17 cases), effusions (14), urine (2), bronchial washings (1) and ovarian cyst fluid (1). The initial diagnosis was made from the cytologic smear in all cases; none had clinical filariasis. Symptomatic vaginal bleeding in 9 of the 17 cases with microfilaria-positive cervicovaginal smears was reflected in the large numbers of red blood cells found in the smear. Blood eosinophilia was present in 11 of 19 cases investigated. Eosinophils were seen in the smears in 20 cases. In the majority of the cases of effusions with microfilariae the effusions were malignant. Significant adherence of inflammatory cells and macrophages to microfilariae was present in 7 of the 35 cases. The significance of these findings is discussed.

Cytologic detection of Wuchereria bancrofti microfilariae in urine collected during a routine workup for hematuria.

A 23-year-old Guyanese man experienced intermittent, total, painless, gross hematuria for a month for which he sought medical attention at the Kings County Hospital Center in Brooklyn. Hematuria was accompanied by weakness but not by frequency of urination or burning on urination. Catheterized urine at the time of cystoscopy and each of two subsequent voided specimens examined cytologically contained sheathed microfilariae. Distinguishing features of the microfilariae were well demonstrated with the Papanicolaou stain. The well-stained nuclei, which did not extend into the clear zone, and the distinct, pale-stained sheath led to the positive identification of the microfilariae as Wuchereria bancrofti. The Papanicolaou stain may well be the stain of choice for the identification of microfilariae in the blood. The excellent detail obtained with this routine cytologic stain is as good as that with Giemsa, which does not stain the sheath.