Clinical History
A 41-year-old woman goes to her gynecologist for a periodic check-up without reporting any symptoms and even without irregular menstrual cycles. The abdomen was soft and non-tender, no pain was evoked, even on deep palpation. The pelvic physical examination with bimanual palpation, but mostly the ultrasound examination with a vaginal probe, showed a suggestive right ovarian neoplasm given the ultrasound characteristics for a dermoid cyst of about 6 cm in maximum diameter. The patient underwent right adnexectomy. The histological examination, as discussed below, revealed a low-grade neuroendocrine tumor in the context of a mature cystic teratoma. The post-operative course was regular and the patient was discharged on the third day from surgery. Subsequently, she was followed by oncologists with the help of periodic abdominal-pelvic CT scan too. The follow-up has been going on for 6 years now and the woman's condition is good.
Anatomopathology FindingsThe material received for histological examination was fixed in buffered 4% formalin and embedded in paraffin. Sections in hematoxylin-eosin were prepared and further sections of the most representative inclusion were set up for different immunohistochemical stains. Immunostaining were performed for: Pancitokeratin AE1/AE3, Synaptophysin, Chromogranin A, CD56, CD99, Vimentin, Smooth muscle actin, Specific muscle actin, Calretinin, Inibin and Ki67, CK 5/6, CK 7, CK 20, CDX2, SATB2, TTF-1 [12].
Macroscopic Examination: the cystic lesion received for histopathological confirmation appeared round, 6x4x1 cm, with smooth walls; when cut it presented a single chamber containing poltaceous material mixed with hair and odontogenic formations.
Microscopic Examination: the sections examined showed normal ovarian structures along with histological patterns of mature cystic teratoma. A circumscribed formation was found in the context of the teratoma, 1.1 cm in maximum diameter, consisting of monomorphic elements, with large eosinophilic and granular cytoplasm, gathered in trabeculae with adequate vascularization (Figure 1).
Figure 1: EE.
No areas of necrosis and the presence of rare mitosis were appreciated.
At the immunohistochemical investigation, the cellular elements described above showed: positivity for Pancitokeratin AE1/AE3, Synaptophysin (Figure 2), CD56, CD99, Vimentin and SATB2 (Figure 3); focal positivity for Chromogranin A(Figure 4) and CDX2; negativity for smooth muscle actin, specific muscle actin, calretinin and inhibin, TTF-1, CK 5/6, CK 7, CK 20.
Figure 2: Sinaptofisina.
Figure 3: SATB2.
Figure 4: Cromogranina.
The mitotic proliferative index of the neoplastic elements, measured with the immunohistochemical staining of Ki67, was less than 3% (
Figure 5).
Figure 5: Ki-67.
The histological diagnosis was low grade neuroendocrine tumour (G1) arising from mature cystic teratoma.
