diff --git a/monai/apps/pathology/metrics.py b/monai/apps/pathology/metrics.py
index 63b9d073a7..ae01d8a1db 100644
--- a/monai/apps/pathology/metrics.py
+++ b/monai/apps/pathology/metrics.py
@@ -9,8 +9,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import json
-from typing import Dict, List, Tuple, Union
+from typing import Dict, List, Tuple
 
 import numpy as np
 
@@ -51,7 +50,7 @@ class LesionFROC:
 
     def __init__(
         self,
-        data: Union[List[Dict], str],
+        data: List[Dict],
         grow_distance: int = 75,
         itc_diameter: int = 200,
         eval_thresholds: Tuple = (0.25, 0.5, 1, 2, 4, 8),
@@ -61,10 +60,7 @@ def __init__(
         image_reader_name: str = "cuCIM",
     ) -> None:
 
-        if isinstance(data, str):
-            self.data = self._load_data(data)
-        else:
-            self.data = data
+        self.data = data
         self.grow_distance = grow_distance
         self.itc_diameter = itc_diameter
         self.eval_thresholds = eval_thresholds
@@ -75,11 +71,6 @@ def __init__(
             box_size=nms_box_size,
         )
 
-    def _load_data(self, file_path: str) -> List[Dict]:
-        with open(file_path, "r") as f:
-            data: List[Dict] = json.load(f)
-        return data
-
     def prepare_inference_result(self, sample: Dict):
         """
         Prepare the probability map for detection evaluation.
diff --git a/tests/test_lesion_froc.py b/tests/test_lesion_froc.py
index 6702997c64..1f2926631f 100644
--- a/tests/test_lesion_froc.py
+++ b/tests/test_lesion_froc.py
@@ -185,7 +185,7 @@ def prepare_test_data():
 ]
 
 
-TEST_CASE_5 = [
+TEST_CASE_6 = [
     {
         "data": [
             {
@@ -207,7 +207,7 @@ def prepare_test_data():
     2.0 / 3.0,
 ]
 
-TEST_CASE_6 = [
+TEST_CASE_7 = [
     {
         "data": [
             {
@@ -229,7 +229,7 @@ def prepare_test_data():
     0.4,
 ]
 
-TEST_CASE_7 = [
+TEST_CASE_8 = [
     {
         "data": [
             {
@@ -257,7 +257,7 @@ def prepare_test_data():
     1.0 / 3.0,
 ]
 
-TEST_CASE_8 = [
+TEST_CASE_9 = [
     {
         "data": [
             {
@@ -305,6 +305,7 @@ def setUp(self):
             TEST_CASE_6,
             TEST_CASE_7,
             TEST_CASE_8,
+            TEST_CASE_9,
         ]
     )
     def test_read_patches_cucim(self, input_parameters, expected):