Solitary nodular goiter - Review of cytomorphologic features in 441 cases

OBJECTIVE: To study the cytomorphologic feature es of solitary nodular goit ers (SNG). STUDY DESIGN: May-Grunwald - Giemsa-stained smears in 441 SNG diagnosed by ultrasonography and fine needle aspiration (FNA) and found to have optimum cellular material at review were subjected to detailed cytologic assessment . The age of the patients ranged from II to 75 years, with a median of 35. Male: female ratio was 69:372. The parameters for cytologic assessment incl uded cellularity, colloid content, acinar formation, papillary formation, i ntranuclear cytoplasmic inclusions, nuclear grooves, marginal vacuoles, Hur thle cells and various inflammatory cells. Histopathology reports on thyroi dectomy specimens were available in 27 cases from two Delhi hospitals. RESULTS: Hyperplastic nodules (68 cases) differed significantly from colloi d goiters (269 cases) by having move cases with excessive cellularity,acina r formation and marginal vacuoles (P < .001). There was also a significant difference with respect to papillary formation and moderate-to-excessive co lloid content (P < .001). As compared to hyperplastic nodules, neoplasms (6 0 cases) had a significantly higher number of cases with papillary formatio n, intranuclear inclusions and nuclear grooves but lower number of cases wi th marginal vacuoles (P < .01-.001). Among neoplasms, usual papillary carci noma (19 cases) differed from follicular neoplasms (20 cases) with respect to acinar formation, papillary formation and nuclear grooves (P < .001). A significant difference was also observed with respect to colloid content an d nuclear inclusions. Follicular variant of papillary carcinomas (FVPC) (10 cases) emerged as a distinct cytologic entity following review and differe d from usual papillary carcinomas in having a higher number of cases with a cinar formation, tubular formation and marginal vacuoles (P < .01-.001) and lower number of cases with nuclear grooves (P = .05). FVPC also differed f rom follicular neoplasms with respect to papillary formation, tubular forma tion, intranuclear inclusions and nuclear grooves (P < .01-.001). Overall c ytohistologic agreement was achieved in 24 of 27 (88.9%) cases. CONCLUSION: Detailed cytologic assessment of FNA smears in SNG was helpful in highlighting parameters that differentiate between various types of goit ers.