Upper New York State Society of Cytology, Inc.

Submitted By: Sharon Leo, MS, CT(ASCP), CMIAC

University of Rochester Medical Center- Strong Memorial Hospital

History

A 42 year man complained of shortness of breath, weight loss, chest/abdominal pain and abdominal bloating. A chest film showed bilateral pulmonary infiltrates. The patient had a history of IV drug abuse and was receiving chemotherapy for chronic lymphocytic lymphoma. A bronchioalveolar lavage was submitted.

Cellular Findings

Numerous hemosiderin-laden macrophages, giant histiocytes, small mature lymphocytes, and occasional eosinophils were present in a hemorrhagic backgound. Several filariform larvae were scattered throughout the specimen.

Diagnosis/Discussion

Negative for malignant tumor cells. Strongyloides stercoralis identified.

The filariform larva range in size from 400 to 500u and has a closed gullet and slightly notched tail. The parasite infection usually occurs in immunosuppressed patients, ie, transplant, chemotherapy or receiving large doses of steroids. This patient(originally from Puerto Rico) was receiving steroids and chemotherapy for chronic lymphocytic lymphoma at a Florida hospital before being transfered to Strong Memorial Hospital to be near family. He had hyperinfection syndrome(spread of organisms to other body sites) and received thiabendazole therapy for the strongyloides.

Strongyloides usually occurs in tropical areas, but can be found in the southern United States and Puerto Rico. The parasite may be asymptomatic or cause occasional mild GI symptoms in a healthy individual. Immunosupressed patients, however, may experience serious complications or death from a disseminated infection.

Larvae enter the body through the skin(often between the toes) and pass through the pulmonary capillaries, to the alveoli, to its preferred location-the mucosa of the small intestine. It is in the small intestine that the filariform larvae lay ova that develop into the rhabditoid larvae that move to the mucosal surface and are excreted in the feces. Once deposited on the soil surface, the rhabditoid larvae may mature into the infective filariform larvae to begin the cycle over. The immunosuppressed patient may develop disseminated disease when the larvae invade other tissues and organs. The number of immunosuppressed patients has increased and pulmonary cytology can be helpful in diagnosing this infective parasite.

References

Orihel TC, Ash LR. Paraites in Human Tissue. ASCP Press, 1995, pp 216-217.