Colloid Bodies in Cutaneous Basal Cell Carcinoma: Clinical and Histologic Correlates-An Analysis of 405 Cases.

Background: Colloid bodies (CB), also known as Civatte bodies, are commonly seen in inflammatory dermatoses and are thought to represent cell degeneration. No studies have investigated the incidence and clinical associations of CB in cutaneous basal cell carcinoma (BCC). The aim of this study is to assess the incidence of CB in BCC lesions and analyze their clinical associations.

Methods: Four hundred and five sequential cases of cutaneous BCC from 396 patients diagnosed from 1/1/2023 to 12/31/2023 in our institution were studied for the presence of CB. Only cases of BCC with a single growth pattern were included. BCC subtype, patient age, location of the lesion, history of previous BCC at other site, smoking history, and allergy history were collected. Cases with and without CB were compared for each parameter using the paired t-test for age and the Chi-square test for categorical data.

Results: Patients were grouped based on the presence of CB into a study group (57 cases) and control group with no CB (348 cases). CB were identified in 14% (57/405) of BCCs. 19% (54/281) of nodular, 12.5% (1/8) of infiltrative, and 1.7% (2/116) of superficial type BCCs had CB. BCC with CB were more common on the face/scalp than other sites (66.7% vs. 34.2%, p < 0.001). Patients with CB were older (median 72 vs. 68 years ±12, p = 0.04), predominantly male (63% vs. 47%, p = 0.02), more frequently had a prior BCC (0.61% vs. 0.38%, p = 0.012), and did not differ in smoking history compared to the control cohort.

Conclusions: We identified CB in 14% of BCCs studied, most commonly in nodular, followed by infiltrative, and least often superficial type. After cohort matching, significant clinical associations of CB in BCC were sun-exposed location and personal history of one or more prior BCC at other site(s). Their pathogenesis is not known, however their presence suggests tumor regression, which may potentially be exploited for new therapies in a subset of patients.