Endometrial Metaplastic/Reactive Changes Coexistent with Endometrial Hyperplasia and Carcinoma: A Morphological and Immunohistochemical Study

Morphological and immunohistochemical evaluation in distinguishing post-radiotherapy serous-like endometrial change (PoRSEC) and serous endometrial intraepithelial carcinoma (SEIC)

Uteri from women undergoing chemoradiotherapy (CRT) may show reactive atypia which may mimic serous endometrial intraepithelial carcinoma (SEIC). We aimed to assess the prevalence and morphological/immunohistochemical features of post-radiotherapy serous-like endometrial changes (PoRSEC) in women undergone CRT for locally advanced cervical cancer, with a focus on the differential diagnosis with SEIC. Consecutive patients with locally advanced cervical cancer undergone CRT between 2011 and 2018 were reviewed. Endometrial histological specimens were assessed for the presence of PoRSEC. Twenty-two cases of SEIC were included for comparison. Immunohistochemistry for p53, p16, and Ki67 was performed. Out of 244 reviewed patients, 36 (14.7%) showed PoRSEC. The degree of nuclear atypia was similar between PoRSECs and SEIC. However, a papillary architecture with areas of confluent papillae was only observed in SEIC. SEIC cases showed a high mitotic activity as opposed to PoRSEC cases. The expression of p53 was aberrant in all SEICs but in none of the PoRSECs; however, 13/36 PoRSECs showed p53 positivity in most tumor cells, potentially mimicking a mutation pattern. A block-type p16 expression was observed in all SEICs and in 16/36 PoRSECs. Mean Ki67 expression was 26.9% in SEIC (range 5-70%) and 8.16% in PoRSEC (range 5-35%). While SEIC showed sharp morphological and immunohistochemical demarcation, PoRSEC were more heterogenous and merged imperceptibly with normal endometrium. In conclusion, PoRSEC may mimic SEIC both morphologically and immunohistochemically. However, a papillary architecture with cytological demarcation is typically observed in SEIC but not in PoRSEC.

Histopathological and histomorphometric analysis of glandular odontogenic cyst-A diagnostic aid

OBJECTIVES

Compare recognized microscopic parameters, including variations in width, plaque-like thickenings, intra-epithelial microcysts, clefts, mucous, hob-nail, ciliated and clear cells, between glandular odontogenic cyst (GOC) and GOC-like cysts, investigate the extent of cyst circumference exhibiting these features, and inflammation.

MATERIALS AND METHODS

Archival records of cysts with histological features of GOC evaluated between 2000 and2020 were retrieved. Slides were revised, and the expression of features throughout the cyst wall was analyzed. Cysts with at least 5 features were classified as GOC, cysts with 3-4 features as GOC-like.

RESULTS

The study included 74 cysts, 47 males M, 25 females (2 unknown gender), aged 19-81 years, 62 (83.8%) GOC, 12 (16.2%) GOC-like. Mandible was involved in 44 (59.5%), maxilla in 30 (40.5%), 18 (25%) were associated with unerupted teeth. Cyst classified as GOC had significantly higher rates of all parameters investigated, (except ciliated and clear cells), than GOC-like cysts (p ≤ 0.05). 26 (40.6%) cases showed GOC features in >50% of cyst circumference, 21 (32.8%) involved 25-50%, 17 (26.6%) <25%. More than 50% circumference involvement was highly and independently predictive for a diagnosis of GOC, <25% was highly and independently predictive for GOC-like (p = 0.003). Hobnail cells (p = 0.008) and plaque-like thickenings (p = 0.038) were significantly more frequent in inflamed cysts.

CONCLUSION

Besides the number and type of histological features, GOC can be characterized by their distribution within the cyst circumference (focal Vs diffuse), and it may serve as a new diagnostic aid. It is suggested that GOC and GOC-like may represent a single spectrum.