Axillary Schwannoma with Extensive Cystic Degeneration
A 40-year-old female presented to orthopedics-out-patient department with complaints of shoulder pain for 6 months and treated for cervical spondylitis, shoulder arthritis and given short wave diathermy and physiotherapy. The pain only worsened. In due course of treatment, she noticed an axillary mass, which increased gradually and further referred to surgery out-patient department for further management. Local examination revealed a 6 × 4 cm oval tender, firm, mobile mass in the left axilla deeper to pectoralis major muscle. A provisional diagnosis of peripheral nerve sheath tumor was made and the case was subjected for fine needle aspiration cytology (FNAC).\nFine needle aspiration from the left axillary mass yielded 30 ml straw colored fluid. The size of the swelling markedly reduced after aspiration and no residual lump was palpated. The smears showed occasional lymphocytes in the proteinaceous background. The cytological diagnosis of benign cystic lesion possibly lymphatic cyst was made and the case was asked for biopsy.\nUltrasonogram showed a cystic lesion. On magnetic resonance imaging, a well-defined, oval shaped, hyperintense cystic lesion, of 6.6 × 4.8 cm in anterolateral compartment of arm was noted []. The lesion was parallel to long axis of neurovascular bundle predominantly in subcutaneous plane with an extension into the inter-muscular plane. The case underwent surgery and the excised mass was sent for the histopathological examination.\nGross examination revealed a cystic mass measuring 6.5 × 4.5 × 2 cm. External surface was smooth and grey white. Cut section revealed uniloculated cyst filled with gelatinous material and the inner lining of the wall was smooth []. Sections from the cyst wall showed hypocellular and hypercellular areas. Hypercellular areas show spindle shaped cells having wavy nuclei arranged in fascicles with focal palisading of nuclei []. Hypocellular areas showed large number of foamy macrophages and loose myxoid stroma []. There was mild nuclear pleomorphism, but no mitotic activity was noted. On IHC tumor cells showed diffuse cytoplasmic positivity for S-100 protein [] and was negative for KI67 []; confirming the diagnosis of schwannoma.