Small-cell neuroendocrine carcinoma in directly sampled endometrial cytology: A monocentric retrospective study of six cases

Small-cell neuroendocrine carcinoma of the cervix accompanied by adenocarcinoma and high-grade squamous intraepithelial lesion

Few cytological reports have described small-cell neuroendocrine carcinoma (SCNEC) in the female genital tract. In the present study, we describe a cytological case of SCNEC accompanied by adenocarcinoma, as well as high-grade squamous intraepithelial lesion (HSIL). A Japanese woman (42 years old) presented with abnormal genital bleeding. A conventional Papanicolaou smear revealed an inflammatory condition with three neoplastic components: SCNEC as irregular aggregates of neoplastic small round cells with nuclear molding and granular chromatin; adenocarcinoma as columnar cell clusters with peripherally located large nuclei, and HSIL as sheets or clusters of dysplastic basal-type squamous cells with irregular hyperchromatic nuclei. Accordingly, a cytodiagnosis of SCNEC with adenocarcinoma and HSIL was made. Owing to the rarity of cervical SCNEC, cytological diagnosis may be difficult. Due to its aggressive clinical behavior, the presence of an SCNEC component should be verified in any cytodiagnosis of adenocarcinoma or HSIL.

Cytologic features of undifferentiated and dedifferentiated carcinomas of the endometrium

BACKGROUND

Undifferentiated carcinoma (UC) is a rare, aggressive subtype of endometrial carcinoma. Dedifferentiated carcinomas (DCs) are UCs associated with a component of well differentiated endometrioid carcinoma. The authors sought to describe the morphologic features of UCs and DCs in cytologic specimens.

METHODS

Cytologic specimens from 23 women (aged 46-86 years; median age, 59 years) were reviewed, including cervicovaginal specimens (n = 7), peritoneal washings (n = 5), touch preparations of core biopsies from various sites (n = 5), fine-needle biopsies of lymph nodes (n = 3), ascitic fluid (n = 1), pleural fluid (n = 1), and intrauterine fluid (n = 1).

RESULTS

There were 10 UCs (43%) and 13 DCs (57%). Tumor cells were arranged as single cells (9 UCs, 90%; 12 DCs, 92%) and 3-dimensional groups (8 UCs, 80%; 11 DCs, 85%). Most cases showed high nuclear-to-cytoplasmic ratios. Nuclear molding was observed in 3 UCs (30%) and in 5 DCs (38%). Nuclear chromatin was often coarsely granular 6 UCs, 60%; 9 DCs, 69%). Nucleoli were inconspicuous in some cases (6 UCs, 60%; 8 DCs, 62%) but were appreciable in others. Necrosis was observed in 5 UCs (50%) and in 5 DCs (38%). Most cases exhibited clean backgrounds, and a few showed acute inflammation. Comparison of the cytologic features of UCs and DCs did not reveal any statistically significant differences.

CONCLUSIONS

UCs and DCs have a spectrum of cytomorphologic appearances that are not pathognomonic, but the presence of some of these (relatively uniform population of predominantly singly dispersed cells with high nuclear-to-cytoplasmic ratios and variably conspicuous nucleoli) should prompt consideration of UC and DC in the differential diagnosis.

Immunohistochemical analysis of SOX2 expression in small-cell neuroendocrine carcinoma of the endometrium

Small-cell neuroendocrine carcinoma (NEC) of the endometrium is an extremely rare and highly aggressive carcinoma. Sex-determining region Y-box 2 (SOX2) is a master transcription factor regulating the self-renewal, maintenance of stem cell properties and pluripotency of embryonic stem cells, and recent studies revealed that SOX2 plays important roles in cancer growth and progression in several types of carcinomas, including small-cell neuroendocrine carcinoma (NEC) of the lung and oesophagus. Few studies to date have analysed the association between SOX2 and endometrioid carcinoma, whereas the expression of SOX2 in small-cell NEC of the endometrium has not been investigated. The aim of the present study was to analyse the expression status of SOX2, p16 and paired-box gene (PAX) 8, a useful Müllerian marker, in endometrial small-cell NEC. A total of 4 patients with small-cell NEC of the endometrium were enrolled (median age, 70 years). Immunohistochemical studies revealed SOX2 expression in 3 patients and p16 expression in all patients. No patients exhibited positive immunoreactivity for PAX8. SOX2 expression has been reported to be associated with the pathogenesis of small-cell NEC of the oesophagus. Therefore, the results of the present study indicated that SOX2 expression plays an important role in the development of small-cell NEC of the endometrium and the oesophagus. Moreover, expression of p16 and loss of PAX8 do not indicate the origin of small-cell NEC of the endometrium.

Neuroendocrine carcinoma diagnosis from bile duct cytological specimens: A retrospective single-center study

Neuroendocrine carcinoma (NEC) in the extrahepatic bile duct is extremely rare and clinically aggressive. Cytological examination of bile and/or bile duct brushing specimens plays an important role in the diagnosis of carcinoma of the extrahepatic bile duct, but only a few articles have described the cytological features of NEC in this area. Thus, we retrospectively analyzed the cytological features of NEC in bile and/or bile duct brushing specimens. Patients with a histopathological diagnosis of NEC who underwent bile and/or bile duct brush cytological examination were enrolled in this study. The cytological features, including the background, arrangement, and shape of the neoplastic cells, and nuclear and cytoplasmic features were reviewed. Six patients with small cell NEC were enrolled, and two of them had pancreatic tumors directly invading the bile duct wall. The cytological specimens showed small and/or large neoplastic cell clusters with occasional single cells in all cases. The neoplastic cells had a high nuclear/cytoplasmic ratio and round-to-oval nuclei with powdery chromatin, inconspicuous nucleoli, and scant cytoplasm. Nuclear molding was a characteristic finding in all cases. One case had an adenocarcinoma component, which was also present in the cytological specimen. Cytological examination of bile and/or bile duct brushing specimens can be useful for the diagnosis of small cell NEC. This is an extremely rare but aggressive carcinoma, and its diagnosis by identifying characteristic cytological features may facilitate early detection and treatment.