Other variants of adenosquamous carcinoma include adenoid basal carcinoma and adenoid cystic carcinoma. Adenoid basal carcinoma simulates the basal cell carcinoma of the skin (51). Nests of basaloid cells extend from the surface epithelium deep into the underlying tissue. Cells at the periphery of tumor nests form a distinct parallel nuclear arrangement, so-called peripheral palisading. An “adenoid” pattern occasionally develops, with “hollowed-out” nests of cells. Mitoses are rare, and the tumor often extends deep into the cervical stroma.
Adenoid cystic carcinoma of the cervix behaves much like such lesions elsewhere in the body. The tumors tend to invade into the adjacent tissues and metastasize late, often 8 to 10 years after the primary tumor was removed. Like other adenoid cystic tumors, they may metastasize directly to the lung. The pattern simulates that of the adenoid basal tumor, but there is a cystic component, and the glands of the cervix are involved (51). Mitoses may be seen but are not numerous.
Sarcoma The most important sarcoma of the cervix is embryonal rhabdomyosarcoma, which occurs in children and young adults. The tumor has grapelike polypoid nodules, known as botryoid sarcoma, and the diagnosis depends on the recognition of rhabdomyoblasts. Leiomyosarcomas and mixed mesodermal tumors involving the cervix may be primary but are more likely to be secondary to uterine tumors. Cervical adenosarcoma is described as a low-grade tumor with a good prognosis (52). If recurrence develops, it is generally a central recurrence that may be treated with resection and hormonal therapy.
Malignant Melanoma On rare occasions, melanosis is seen in the cervix. Malignant melanoma may arise de novo in this area. Histopathologically, it simulates melanoma elsewhere, and the prognosis depends on the depth of invasion into the cervical stroma.
The classification of neuroendocrine cervical carcinoma includes four histologic subtypes: (i) small cell, (ii) large cell, (iii) classical carcinoid, and (iv) atypical carcinoid (53). Neuroendocrine tumors of the cervix are rare, and treatment regimens are based on small case series of patients.
Small cell (neuroendocrine type) carcinoma of the cervix is aggressive in nature and is similar to cancer arising from the bronchus (54). The hallmark of neuroendocrine tumors is their aggressive malignant behavior with the propensity to metastasize. At the time of diagnosis, it is usually disseminated, with bone, brain, liver, and bone marrow being the most common sites of metastases. In one study of 11 patients with disease apparently confined to the cervix, a high rate of lymph node metastasis was noted (55). Pathologically, the diagnosis is aided by the finding of neuroendocrine granules on electron microscopy and by immunoperoxidase studies that are positive for a variety of neuroendocrine proteins such as calcitonin, insulin, glucagon, somatostatin, gastrin, and adrenocorticotropic hormone (ACTH). In addition to the traditional staging for cancer of the cervix, these patients should undergo bone, liver and brain scanning and bone marrow aspiration and biopsy to evaluate the possibility of metastatic disease. Therapyconsists of surgery, chemotherapy, and radiation. Because patients with early-stage disease have distant metastases, multimodal therapy is recommended. The main active chemotherapeutic agent is etoposide.
Local therapy alone gives almost no chance of cure of small cell carcinoma. Regimens of combination chemotherapy improved the median survival rates in small cell bronchogenic carcinoma, and these regimens are used for treatment of small cell carcinoma of the cervix.