Cytological diagnosis of parasites presenting as superficial nodular swelling: report of 35 cases

Abstract

Parasitic infestation often present with superficial nodular swelling. Fine needle aspiration cytology plays an important role in prompt diagnosis of the disease. To study the role of FNAC in the diagnosis of parasites presenting as skin or subcutaneous nodules. Total 361 cases of superficial swellings at various sites were subjected to fine needle aspiration cytology. Out of the 361 cases, 35 cases were diagnosed as suggestive of parasitic infestation. These 35 cases form the study group. In 14 cases out of 35 cases, a definitive diagnosis of parasitic infestation was made as parasite or fragments of parasite were seen in the aspirate. In 21 cases, neither parasite nor fragments could be identified on the aspirates and a diagnosis of parasitic inflammation was suggested on the basis of other cytomorphological findings. In 17 of these cases, a biopsy correlation was available, which revealed definitive parasite in 8 cases and the remaining 9 were reported as suggestive of parasitic cyst. The cytological diagnosis was confirmatory in cases where the parasite fragment were identified in the smears. However, in other cases, clear aspirate, presence of eosinophils, macrophages and typical granular dirty background are the features which should prompt the cytologist to the possibility of parasitic infestation.

Keywords: Cytodiagnosis; Parasite; Superficial swelling.

Fig. 1

a, b FNAC smears demonstrating wall of cysticercus cellulosae with calcareous spherule (arrow) surrounded with inflammatory cells

Fig. 2

Photomicrograph of tissue section showing cysticercosis larva enclosed in a thin fibrous cyst wall

Fig. 3

FNAC smear showing adult gravid worm containing coiled form of microfilarial larvae

Fig. 4

FNAC smear demonstrating fragments of lamellated membrane

Fig. 5

Smear shows non necrotizing epithelioid cell granuloma in a dirty granular background

Fig. 6

Smear shows degenerating muscle fragment (mimicking parasitic fragment) against a dirty background