Gastrointestinal stromal tumors are the most common mesenchymal tumors of the gastrointestinal tract. These tumors are present in almost all case mutations of KIT-CD117. When located in different places other than the gastrointestinal tract they are called extragastrointestinal stromal tumors (EGISTs). We present the case of a 70-year old patient with abdominal pain. Computed tomography (C/T) and ultrasound (U/S) indicated the existence of a hypoechoic enlarged 9.6 x 10 cm uterus due to leiomyoma. The clinical condition of the patient deteriorated and obtained the characteristics of an acute abdomen. The patient underwent urgent exploratory laparotomy, which revealed the incidental existence of a large tumorous formation in the pouch of Douglas. A total abdominal hysterectomy, bilateral ovarectomy, omentectomy, and tumor resection from the rectouterine pouch were performed. Histology analysis confirmed the diagnosis of a malignant EGIST. EGISTs are infrequent in pelvis. In our case, pelvic EGIST led to an acute pain symptomatology obtaining characteristics of invasive uterine leiomyosarcoma. Pelvic imaging with classical methods of U/S and C/T may lead to confusion and false diagnosis. To the best of our knowledge, this is the first case report about an EGIST located in the rectouterine pouch of Douglas leading to acute abdomen symptomatology.

Objective: To present the cytological features of a very rare and lethal ovarian neoplasm occurring in the young. Study Design: We reviewed the cytological findings as they presented in touch imprints obtained from an ovarian mass sent to our department for frozen section investigation. Results: Smears were highly cellular. The cells were of intermediate size with a moderate amount of microvacuolated, pale, or eosinophilic cytoplasm with indistinct cell borders. The nuclei were of round or oval shape with mild to moderate atypia and indistinct nucleoli. Conclusions: The diagnosis of small cell carcinoma of the ovary can be challenging even histologically. Cytology can be an invaluable adjunct to hematoxylin-eosin sections both pre- or intraoperatively. Although it is a very rare occurrence and cytological results are almost absent in the literature, our case can make cytopathologists more acquainted with the cytological features of this rare tumor entity especially in association with a characteristic clinical profile. Furthermore, the cytological features of small cell carcinoma of the ovary, large cell variant, have only rarely been described in the literature.

Background: Malignant myoepithelioma of the breast is an exceptionally rare, aggressive tumor with a diverse morphology, the cytological features of which have only occasionally been described. Case Report: Our case comprises a 74-year-old woman who was admitted to our hospital with an erythematous, inflammatory-like mass of her left breast with nipple ulceration, and clinically fixed to the chest wall. The woman underwent fine-needle aspiration and biopsy. The aspirates consisted mainly of loose aggregates of large, highly pleomorphic, polygonal epithelioid cells as well as aggregates of spindle cells with prominent, easily detectable mitoses and single, multinucleated pleomorphic giant cells. The cytological diagnosis was consistent with high-grade malignancy. Histologically, the lesion consisted broadly of eosinophilic epithelioid cells with globoid cytoplasm in a reticulated, angiomatoid pattern and of spindle (sarcomatoid) cells in a storiform pattern, highly suspicious of angiosarcoma. A final diagnosis of malignant myoepithelioma was made. Conclusion: We present the cytological findings in comparison with the unusual histological features of a malignant myoepithelioma of the breast. A high degree of suspicion with a keen eye for morphological details coupled with relevant immunohistochemistry will aid in arriving at the correct diagnosis.

Newly diagnosed invasive breast cancers should be evaluated for Human Epidermal Growth Factor Receptor 2 (HER2) status by immunohistochemistry (IHC) and/or in situ hybridisation (ISH) to determine eligibility for trastuzumab or other HER2-targeted therapies. Previous reports of high discordance rates between IHC and ISH have raised concerns over the accuracy of HER2 testing, especially when IHC is conducted locally. This study aimed to determine the rate of false-negative IHC results at three pathology centres (one central, two local) in Greece by central retesting of 240 prospectively collected invasive breast cancers scored as IHC 0/1+ at initial testing. All samples were from female patients (median age 58.0 years). Initial IHC tests utilised either the CB11 (159/239; 66.5%) or 4B5 (80/239; 33.5%) antibodies and were scored as 0 in 105/240 cases (43.8%) and 1+ in 135/240 cases (56.3%). All samples were centrally retested by automated silver in situ hybridisation (SISH). Of 237 samples with SISH staining suitable for assessment, 223 (94.1%; 95% confidence interval 90.3–96.5%) were classed as SISH-negative (HER2:chromosome enumeration probe 17 (CEP17) <1.8). Eight tested SISH-positive (HER2:CEP17 >2.2), providing a false-negative rate of 3.4%. A further four samples (1.7%) exhibited equivocal amplification status (HER2:CEP17 1.8–2.2) and two (0.8%) showed polysomy of chromosome 17. The proportion of SISH-negative results did not significantly differ between the IHC 0 and 1+ subgroups (95.2% vs. 93.2%; p=0.505). In conclusion, the low observed rate of false-negative IHC results in this study supports the use of IHC for initial HER2 status assessment in local or central laboratories in Greece.