Disseminated cutaneous rhinosporidiosis: diagnosis by fine needle aspiration cytology.

Rhinosporidiosis is a chronic granulomatous disease of the nasal cavity caused by Rhinosporidium seeberi,1-4 which is an aquatic protozoan formerly considered to be a fungus.5 The disease, first described by Seeber in Argentina and O’Kinealy in India,1 is endemic to southern India and Srilanka.1-4 However, sporadic cases have been reported from other parts of the world including the United States, Brazil, Argentina, South Africa and Italy. Other rare sites infected with R seeberi include the bronchi, larynx, pharynx, conjunctivae and epithelia of the genitalia.1 Isolated cases of Rhinosporidoma of bone and cutaneous rhinosporidiosis without disease elsewhere are also known.3,6,7 The histology in rhinosporidiosis is simple and consists of many sporangia at various stages of maturation, surrounded by a double layer of chitin and cellulose and filled with a large number of spores.1 As for the cytologic diagnosis, there have been rare case reports, diagnosed using nasal scrapes, smears and irrigation fluids.3,8 Kavishwar et al reported a case of disseminated cutaneous rhinosporidiosis diagnosed on fine needle aspiration cytology (FNAC).9 Below, we document a similar case, emphasizing the importance of fine needle aspiration (FNA) in the preoperative diagnosis of rare cases of disseminated rhinosporidiosis. A 51-year-old male presented with multiple, large (5 × 5–8 × 8-cm) sessile firm, subcutaneous nodules on both the thighs and right sole (Figure 1) that had been present for 2 years. The swelling on the sole was ulcerated. FNA of the swellings was performed using a 23gauge needle. May-Grünwald-Giemsa– and Papanicolaoustained smears showed moderate cellularity with a large number of globular sporangia at various stages of maturation and measuring 10–200 μm (Figure 2). Sporangia contained numerous endospores. The hemorrhagic background showed several singly scattered endospores with an epithelioid, granulomatous reaction. Eosinophils were conspicuously absent. Detailed history revealed removal of a nasal mass 6 years earlier, reported as rhinosporidiosis. Histopathologic examination of the cutaneous nodules confirmed the cytologic diagnosis. Mucicarmine and periodic acid–Schiff (PAS) stain highlighted the capsule of spores. Skin lesions in rhinosporidiosis are rare and usually present as papillomas with or without nasal involvement.4 As for disseminated cutaneous rhinosporidiosis, only 3 cases have been documented.10 Dissemination from a primary nasal or conjunctival lesion occurs either due to autoinoculation or hematogenous spread.3,11 Visceral involvement, particularly of the liver, lungs and brain, has been reported in rare, fatal cases of dissemination.12 To our knowledge, this is the second case of disseminated rhinosporidiosis diagnosed on FNAC. The characteristic cytomorphology with distinctive sporangia and spores at various stages of maturation permits a definitive diagnosis of rhinosporidiosis. In immunocompromised patients, cytologic differentiation from Coccidioidomycosis immitis can be performed with PAS staining.3,11 LETTERS TO THE EDITORS