{'fraction_non_alphanumeric': 0.04250720461095101, 'fraction_numerical': 0.03386167146974063, 'mean_word_length': 4.623481781376518, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Adenoid Cystic Carcinoma in Children and Young Adults: A Clinicopathological Study of 12 Cases.

OBJECTIVE
To investigate the clinicopathological characteristics, immunoprofile and molecular alterations of ACC in children and young adults.


MATERIALS AND METHODS
Twelve cases of ACC were included. MYB, MYBL1, Ki-67, type IV Collagen, Laminin and LAMB1 expression were detected by immunohistochemistry. MYB and MYBL1 rearrangements were detected by fluorescence in situ hybridization.


RESULTS
Among 12 patients, 4 were female and 8 were male. Seven cases (58.3 %) located in major salivary glands and 8 cases (66.7%) were classified as Grade I. Ten tumors (83.3%) had collagenous and hyalinized stroma. MYB was positive in 83.3% cases and the average Ki-67 labeling index (LI) was 8.3%. LAMB1, type IV Collagen and Laminin was positive in 91.7%, 66.7% and 58.3% cases, respectively. Besides, 3 out of 8 tumors had MYB rearrangement. Cases without MYB rearrangement were negative for MYBL1 expression and MYBL1 rearrangement. The average follow-up time was 91.8 months. Four patients had recurrent diseases.


CONCLUSIONS
ACC in children and young adults was seen more frequently in males and major salivary glands. Most cases had ECM and hyaline stroma. Grade III tumors, higher Ki-67 LI, negative expression of type IV Collagen and Laminin showed a tendency of higher recurrence rate.