Pathology of the uterine corpus

Endometrial hyperplasia/adenocarcinoma. A conventional approach

Hyperplasia of the endometrium is a process characterized by an irregular, noninvasive proliferation of glands with a variable amount of stroma. Precise classification of endometrial hyperplasia in biopsy material is important in order to identify those hyperplasias that are likely to be precursors of endometrial adenocarcinoma. The current World Health Organization (WHO) classification provides a scheme that has become widely accepted, primarily dividing hyperplasias in to those with and those without cytologic atypia while the degree of glandular crowding (simple vs. complex) has secondary importance. A wide variety of other endometrial changes, ranging from artifacts, metaplasias and polyps to well-differentiated adenocarcinoma must be considered in the differential diagnosis. Well-differentiated adenocarcinoma is diagnosed when one of 3 essential criteria is found in biopsy specimens: (1) a confluent gland pattern; (2) an extensive papillary pattern; or (3) a desmoplastic stromal response. Using the WHO classification allows segregation of endometrial hyperplasia into clinically meaningful categories. Strict morphologic criteria also enable separation of hyperplasia from well-differentiated adenocarcinoma.

Evaluation of the relationship between adenosarcoma and carcinosarcoma and a hypothesis of the histogenesis of uterine sarcomas

The terminology of uterine sarcomas is confusing and has been inconsistently applied. The relationships among the various types of uterine sarcomas are unknown. To elucidate the relationship between carcinosarcoma (malignant mullerian mixed tumor) and adenosarcoma, a series of 26 consecutive endometrial carcinosarcomas was evaluated for the presence of an adenosarcoma-like component. Four of 26 carcinosarcomas (15%) had an adenosarcoma-like component. The clinical and pathologic features of these tumors were otherwise similar to ordinary endometrial carcinosarcomas. A histogenetic schema for uterine sarcomas is proposed, interrelating endometrial stromal sarcomas, adenosarcomas with and without sarcomatous overgrowth, and poorly differentiated sarcoma not otherwise specified. Although most carcinosarcomas are accepted as being metaplastic or sarcomatoid carcinomas, it is suggested that the carcinomatous component of 8% to 16% of carcinosarcomas arise within, or in the endometrium adjacent to, an adenosarcoma. This latter group is then integrated into the histogenetic schema. Observations based on our data and the limited data in the literature that support this hypothesis include: 13% of endometrial carcinosarcomas have gross and microscopic features of collision tumors, 13% have an adenosarcoma-like component, 16% have a low-grade stroma, and approximately 8% are biclonal indicative of a collision tumor. The most parsimonious interpretation of these data indicates that approximately 8% to 16% of endometrial carcinosarcomas arise because of malignant transformation of the epithelial component within, or in the endometrium adjacent to an adenosarcoma.

Endometrial low-grade stromal sarcoma with ovarian sex cord-like differentiation: report of two cases with an immunohistochemical and flow cytometric study

Two cases of endometrial low-grade stromal sarcoma with ovarian sex cord-like differentiation occurring in a 39-year-old woman and a 42-year-old woman are presented. Both tumors, which were intramyometrial and measured 7.5 cm and 7.0 cm in greatest diameter, respectively, showed a multinodular, ill-demarcated, and yellowish white cut-surface. Histologically, most parts of the tumors were composed of trabecular, cord-like, or plexiform arrangements that were reminiscent of the growth pattern seen in ovarian sex cord tumors. Features of conventional endometrial low-grade stromal sarcoma were only focally observed. The tumors showed infiltrative margins and lymphatic invasion. The tumor cells were positive for vimentin, desmin, alpha-smooth muscle actin, and muscle actin (HHF35). The tumors were also positive for both estrogen and progesterone receptors. Both tumors were DNA diploid as determined by flow cytometry. One patient had recurrences, including osteolytic lesions in the pelvic bones, but had no evidence of recurrence or metastasis 11 months after the last surgery. The other patient had no evidence of tumor in a limited follow-up. Familiarity with the neoplasm and other uterine mesenchymal tumors with ovarian sex cord-like differentiation by gynecologists and pathologists is essential in avoiding misdiagnosis because adjuvant hormonal therapy may be effective in treating low-grade stromal sarcomas.

Müllerian adenosarcoma of the cervix: differential diagnosis, histogenesis and review of the literature

A new case is reported of müllerian adenosarcoma, presenting as a 'benign cervical polyp' protruding through the vulva of a 44 year-old woman admitted with abnormal vaginal bleeding. This report emphasizes the importance of a careful examination of the stroma and special features of the entrapped glands in order to contribute to an earlier and proper diagnosis. The literature is reviewed and the probable histogenesis of this tumor and differential diagnosis with embryonal rhabdomysarcoma (sarcoma botryoides), adenofibroma, malignant mesodermal tumor and carcinosarcoma is discussed.

Nucleolar organizer regions as markers of endometrial proliferation: a study of normal, hyperplastic, and neoplastic tissue

Nucleolar organizer regions (NORs) are loops of DNA that transcribe to ribosomal RNA. They can be visualized as intranuclear black dots by histochemical staining with a colloid silver solution. We applied this method to 78 sections of endometrial tissue obtained either from curettage or from hysterectomy specimens. The histological diagnoses were as follows: normal proliferative (N = 9) or secretory (N = 5) endometrium, simple hyperplasia (N = 10), complex hyperplasia (N = 18), atypical hyperplasia (N = 8), and adenocarcinoma (N = 28). Mean silver-stained NOR (AgNOR) counts per cell were 3.2 (standard error of the mean [SEM], 0.2) in normal proliferative and 2.7 (SEM, 0.2) in normal secretory epithelium, and increased to 4.1 (SEM, 0.3) in simple hyperplasia, to 5.4 (SEM, 0.4) in complex hyperplasia, to 8.1 (SEM, 0.7) in atypical hyperplasia, and finally to 10.0 (SEM, 0.5) in endometrial carcinoma. The differences were significant (one-factor analysis of variance [ANOVA], P < .001). A slight increase but no significant difference was seen between the mean AgNOR counts in endometrial carcinomas of different histological grades. Our study suggests that AgNOR counts are reliable markers of endometrial proliferation and allow a clear distinction between benign, premalignant, and malignant epithelial changes. Our AgNOR findings in endometrial hyperplasia support the concept of various degrees of hyperplasia that can be differentiated on morphological grounds.

Complex karyotypic alterations in an endometrial stromal sarcoma

Cytogenetic investigation of a low-grade endometrial stromal sarcoma (ESS) revealed structural rearrangements of chromosomes 3, 6, and 7. The karyotypic findings in the few cases of ESS reported reveal recurrent involvement of both homologues of chromosome 7, with less consistent changes affecting chromosomes 6 and 17. The cytogenetic and histologic features of these uterine stromal tumors require further study.

Detection of human papillomaviruses from histologically normal lymph nodes of Japanese cervical cancer patients by nested polymerase chain-reaction assay

To determine the prognostic significance of human papilloma virus (HPV) DNA in histologically normal lymph nodes, we developed a nested polymerase chain-reaction (PCR) method on HPV16,18 and 33 DNAs for formalin-fixed, paraffin-embedded tissues. We investigated 370 histologically normal lymph nodes from 15 patients treated for stage-IB/IIB (FIGO) invasive cervical cancer. HPV16 DNA was detected in 7 (47%) and HPV18 DNA in 3 (20%) of the cervical cancers. Examination of histologically normal lymph nodes from these 10 patients by nested PCR revealed HPV DNA in 5 (50%) of them; in all cases HPV type in lymph nodes and tumor was the same. Two of these 5 patients had a recurrence (pelvic cavity or lung) and died of cancer, although all 5 had had pelvic radiotherapy after radical hysterectomy and lymphadenectomy. These findings indicate that nested PCR is useful for evaluating early lymph-node involvement retrospectively in HPV-positive cases.

Production and characterization of a polyclonal antibody to the c-erbB-3 protein: examination of c-erbB-3 protein expression in adenocarcinomas

A polyclonal rabbit antibody was raised to the c-erbB-3 protein using a synthetic peptide corresponding to amino acids 1229-1241 of the predicted protein sequence of c-erbB-3. In Western blot analysis this antibody detects a single band at approximately 165 kD in a c-erbB-3 transfected (293/HER-3) human cell line. c-erbB-3 protein expression was then examined in a variety of adenocarcinomas. Expression of c-erbB-3 protein was indicated by membrane and/or cytoplasmic tumour cell immunoreactivity in formalin-fixed, paraffin-embedded tissue sections. c-erbB-3 protein was detected in a series of 13 out of 14 primary breast carcinomas, 3 of 5 gastric adenocarcinomas, 8 of 9 colonic adenocarcinomas, 2 of 9 prostatic adenocarcinomas, 0 of 6 renal cell carcinomas, 1 of 4 primary lung adenocarcinomas, and 5 of 7 endometrial adenocarcinomas. Immunohistochemical expression of the c-erbB-3 protein appears to be a relatively common event in adenocarcinomas, and further studies are now warranted to establish the role of the c-erbB-3 protein in neoplasia.