Introduction: Despite progress in understanding its pathogenesis, there has not yet been found any independent predictive marker of aggressive behavior of pituitary adenomas, to facilitate the treatment and monitoring of patients.
Aim: To analyze the expression of folliculo-stellate cells by immunostaining with S-100 protein, in a series of patients with pituitary adenomas followed for at least seven years.
Patients and methods: A retrospective study of 51 patients diagnosed with a pituitary adenoma between 2006 and 2008 was performed, according to current criteria established by the World Health Organization. The S-100 expression in folliculo-stellate cells was immunohistochemically evaluated, correlating it with clinico-radiological and histopathological tumor parameters and post-operative progression/recurrence.
Results: Of 51 tumors, 40 were classified as typical and 11 as atypical pituitary adenomas. Most typical pituitary adenomas showed positive folliculo-stellate cells for S-100 (mean: 3.93%); atypical had little/no cell S-100 positive (mean: 0.83%). There were no significant differences in the expression of S-100 with respect to age or sex of the patient, size, invasiveness or post-operative tumor recurrence.
Conclusions: In our study group, with the exception of non-functioning adenomas immunopositive for prolactin, with the lowest and highest average of all subtypes in both groups (typical 0.25% vs atypical 9.24%; p = 0.0028), the predictive factor of tumor aggressiveness for pituitary adenomas, is not represented by a low value of S-100 in folliculo-stellate cells, not allowing select patients for intensive post-operative treatment.
Title: Implicacion pronostica de las celulas foliculo-estrelladas en adenomas hipofisarios: relacion con el comportamiento tumoral.
Introduccion. A pesar del progreso en la comprension de su patogenia, no se ha encontrado ningun marcador predictivo independiente del comportamiento agresivo de los adenomas hipofisarios que facilite el tratamiento y seguimiento de pacientes afectados. Objetivo. Analizar la expresion de celulas foliculo-estrelladas, mediante inmunomarcacion con proteina S-100, en una serie de pacientes con adenomas hipofisarios seguidos durante al menos siete años. Pacientes y metodos. Estudio retrospectivo de 51 pacientes diagnosticados de adenoma hipofisario entre 2006 y 2008, segun los criterios vigentes de la Organizacion Mundial de la Salud. Se evaluo inmunohistoquimicamente la expresion de S-100 en celulas foliculo-estrelladas, y se correlaciono con parametros clinicorradiologicos e histopatologicos del tumor y la progresion/recurrencia postoperatoria. Resultados. De 51 tumores, 40 se clasificaron como adenomas hipofisarios tipicos y 11 como atipicos. La mayoria de los tipicos mostro celulas foliculo-estrelladas positivas para S-100 (media: 3,93%); los atipicos tenian pocas o ninguna celula S-100 positivas (media: 0,83%). No hubo diferencias significativas en la expresion de S-100 con respecto a la edad o sexo del paciente, tamaño, invasividad o recidiva tumoral posquirurgica. Conclusiones. En el grupo de estudio, a excepcion de los adenomas no funcionantes inmunopositivos para prolactina, con la media mas baja y mas alta de todos los subtipos en ambos grupos (tipicos, 0,25%, frente a atipicos, 9,24%; p = 0,0028), el factor predictivo de agresividad tumoral para los adenomas hipofisarios no esta representado por un bajo valor de S-100 en las celulas foliculo-estrelladas, lo que no permite seleccionar a pacientes para un tratamiento postoperatorio intensivo.