Background: Tumor diathesis (TD) refers to the granular proteinaceous precipitates on the slide surface of cytologic (Pap) smears. Found in the background of smears from some, but not all, invasive carcinoma cases, TD is present in the majority of smears from large cell nonkeratinizing carcinoma. It is more pronounced than keratinizing SCC also is almost always present in small cell carcinoma.  Smears from patients with adenocarcinoma are frequently associated with dense inflammatory and fresh blood exudates and less often there is a recognizable tumor diathesis.

Methods: To determine the prevalence of TD in cervicovaginal smears from patients with uterine cervix carcinoma, cytologic smears and histologic slides of 46 patients with histologically-confirmed uterine cervix carcinoma were reviewed for the presence or absence of TD, red blood cells and neutrophils on cytologic smears, as well as depth of invasion, histologic types and grade of differentiation of tumor on histologic slides.

Results: TD was identified in 28 smears (60.9%), 18 patients with squamous cell carcinoma (62.1%), seven patients with adenocarcinoma (58.3%), two patients with adenosquamous carcinoma (66.7%) and one patient with endometrial carcinoma that involved the uterine cervix. TD was seen in smears from four (33.3%) patients with uterine cervix carcinoma with invasion <5 mm and 17 (65.4%) carcinomas with invasion >5mm. However, some of the patients with invasive carcinoma lacked TD on the cytologic smears. Red blood cells were identified on 16 (34.8%) smears.

Conclusions: Although TD is the hallmark of invasive carcinoma of the cervix on cytological smears, there have been few studies performed on it. We found that tumors with greater depth of invasion and reduced differentiation are associated with TD cytologic smears. TD was absent in some cases, particularly in micro-invasive carcinoma. This study reinforced what has been recognized from other studies.