Final answer:
The ICD-10 code for the patient's admission for biopsy of an enlarged lymph node in the area of the left axilla is C77.8.
Step-by-step explanation:
The ICD-10 code for the patient's admission for biopsy of an enlarged lymph node in the area of the left axilla would be C77.8. This code represents secondary and unspecified malignant neoplasm of lymph nodes. Since the pathology report showed normal lymphatic tissue with no evidence of metastatic spread, the final diagnosis would not indicate metastasis, ruling out the need for an additional code for metastasis.