Utility of MIB-1 and estrogen and progesterone receptor in distinguishing between endometrial stromal sarcomas and endometrial stromal nodules, highly cellular leiomyomas

Endometrial Stromal Nodule: A Rarity and a Pathological Challenge

Endometrial stromal tumors are rare, and endometrial stromal nodule is the least common. In the region of Middle Jutland, Denmark, only two cases are reported since 1995. The nodules are benign; nevertheless, hysterectomy is the treatment of choice. Tumor margins are required for diagnosis and essential to differentiate it from an invasive stromal sarcoma whose prognosis is very different. We report a rare case of a 38-year-old woman, with presurgical diagnosis of a uterine tumor/polyp. She presented with nausea and changes in bleeding pattern and initially had a transcervical polyp resection performed. Histopathological examination showed the presence of an endometrial stromal tumor with unclear margins, and an invasive malignant endometrial sarcoma could not be excluded. Pathological examination revealed an endometrial stromal nodule with invasion, not exceeding three mm. Endometrial stromal tumors are interesting due to their rare existence and difficulties in establishing a histological diagnosis. Although endometrial stromal nodules are benign entities, they must be differentiated from the other invasive malignant stromal tumors, which may change the final prognosis. No preoperative diagnostic tools are at hand, and benign as well as malignant tumors are treated with hysterectomy.

Can proliferation biomarkers reliably predict recurrence in World Health Organization 2003 defined endometrial stromal sarcoma, low grade?

An estimated 1500–3000 invasive Endometrial Stromal Sarcomas (ESS) cases annually occur worldwide. Before 2003, ESS was divided as low and high grade ESS based on mitotic activity. In 2003 the WHO changed the names, excluded mitoses and made nuclear atypia and necrosis the essential diagnostic criteria to distinguish ESS, Low Grade (ESS-LG, recurrence-free survival >90%) and Undifferentiated Endometrial Sarcoma (UES, poor prognosis). We have evaluated in WHO2003 defined ESS-LG whether proliferation biomarkers predict recurrence. Using survival analysis, the prognostic value of classical mitosis counts (Mitotic Activity Index, MAI) in haematoxyllin-eosin (H&E) sections, and immunohistochemical proliferation biomarkers (Ki-67 and PhosphoHistone-3 (PPH3)) were examined in 24 invasive endometrial stromal sarcomas. Three of 24 (12.5%) ESS-LG recurred. The MAI, PPH3 and Ki-67 were all prognostic (P = 0.001, 0.002 and 0.03). MAI values were >3 in the recurrent cases, but never exceeded 10 (the classical threshold for low and high grade). Non-recurrent cases had 0≤MAI≤3. PPH3 and Ki67 counts can be easier to perform than MAI and therefore helpful in the diagnosis of ESS, Low Grade. In conclusion, in this small study of WHO2003 defined ESS-LG, high levels of proliferation as measured by MAI, PPH3 and Ki-67 are predictive of recurrence. Larger studies are required to confirm these results.

Molecular Genetics of Mesenchymal Tumors of the Female Genital Tract

Mesenchymal tumors of the female genital tract are a heterogeneous group of neoplasms that can be classified based on cellular differentiation into 3 main groups: smooth muscle tumors, endometrial stromal tumors, and other differentiated and undifferentiated tumors. Genomic analysis techniques have revealed important genetic aberrations such as the t(7;17) translocation, resulting in JAZF1-JJAZ1 gene fusion, characteristic of endometrial stromal tumors. These analyses have demonstrated genetic complexity and heterogeneity in many mesenchymal tumor types. This article focuses on current understanding of the molecular genetics of mesenchymal tumors of the female genital tract, with emphasis on diagnostic and prognostic molecular features.

[Mesenchymal uterine tumors. Stromal tumors and other rare mesenchymal neoplasms]

Uterine stromal neoplasms are classified into endometrial stromal nodules and stromal sarcomas, as well as undifferentiated sarcomas. The two former groups demonstrate identical histological composition, consisting of small monomorphous cells with scant cytoplasm and round nuclei and typically contain numerous arteriolar-type vessels. Stromal tumors are distinct from stromal nodules by virtue of their myometrial and vascular invasion. Undifferentiated sarcomas consist of polymorphic cells and lack any cytological similarity to the stroma of normal proliferative endometrium. There is no smooth or striated muscle differentiation. Adenosarcomas are mixed neoplasms with a low grade stromal sarcoma component containing benign glands, which are surrounded by condensed neoplastic stroma. Typical uterine tumors resembling ovarian sex cord tumors (UTROSCT Type2) show predominant sex cord differentiation in a well circumscribed nodule. Focal sex cord differentiation may occur in stromal nodules and stromal sarcomas (UTROSCT Type2).

Treatment of early uterine sarcomas: disentangling adjuvant modalities

Uterine sarcomas are a rare group of neoplasms with aggressive clinical course and poor prognosis. They are classified into four main histological subtypes in order of decreasing incidence: carcinosarcomas, leiomyosarcomas, endometrial stromal sarcomas and "other" sarcomas. The pathological subtype demands a tailored approach. Surgical resection is regarded as the mainstay of treatment. Total abdominal hysterectomy and bilateral salpingo-oophorectomy represents the standard treatment of uterine sarcomas. Pelvic and para-aortic lymph node dissection in carcinosarcomas is recommended, given their high incidence of lymph node metastases, and may have a role in endometrial stromal sarcomas. Adjuvant radiation therapy has historically been of little survival value, but it appears to improve local control and may delay recurrence. Regarding adjuvant chemotherapy, there is little evidence in the literature supporting its use except for carcinosarcomas. However, more trials are needed to address these issues, especially, their sequential application. Patients with uterine sarcomas should be referred to large academic centers for participation in clinical trials.

Expression of cyclooxygenase-2, c-kit, progesterone and estrogen receptors in uterine smooth muscle tumors: differential diagnosis

We examined the expression pattern of cyclooxygenase-2 (COX-2) and c-kit in uterine smooth muscle neoplasms and tried to determine the role of these markers in differential diagnosis. Archival tissue from 64 patients with uterine smooth muscle neoplasms (20 leiomyomas (LMs), 22 atypical leiomyomas (ALMs), and 22 leiomyosarcomas (LMSs)) was immunostained with antibodies against estrogen (ER) and progesterone receptors (PR), COX-2 and c-kit. 7 of 20 LM cases and 5 of 22 ALM cases were immunopositive for COX-2, whereas none of the LMS cases stained immunopositive (p< or =0.05). 4 of 20 LM cases and 5 of 22 ALM cases were immunopositive for c-kit, whereas 15 of 22 LMS cases showed c-kit immunopositivity (p< or =0.05). In conclusion, very few LMs and ALMs show COX-2 immunopositivity. LMSs usually do not express COX-2. COX-2 expression in smooth muscle tumors is not a prominent feature. Therefore, COX-2 inhibitors may not be useful in LMS therapy. C-kit was significantly expressed in uterine LMSs.