CD10 is a characteristic marker of tumours forming morules with biotin‐rich, optically clear nuclei that occur in different organs

Follicular thyroid carcinoma with an unusual glomeruloid pattern of growth

“…This PTC variant is histologically characterized by a mixture of cribriform, follicular, papillary, trabecular, solid, and spindle cell patterns of growth, with morular foci showing peculiar nuclear clearing (biotin rich nuclei); at the molecular level, there are somatic RET/PTC rearrangements as well as alterations in the Wnt signaling pathway [4,7]. In the present tumor, clinical data of FAP, morular structures with characteristic positivity for CD10, alterations in the APC gene and/or aberrant nuclear location of β-catenin were not found [4,7,8]. Columnar cell carcinoma of the thyroid also shows significant morphologic overlap with our case (pseudostratified columnar cells, some of which may contain supranuclear and subnuclear cytoplasmic vacuoles reminiscent of those of early secretory endometrium, solid areas, and elongated and empty follicles resembling tubular glands), but this case differs specifically in the lack of papillae, the presence of glomeruloid structures, and the immunoprofile of CKs [1].…”

“…EMA, clone AE1/AE3, and CKs 7,8,19, and 20 are all negative in the renal glomerulus, suggesting that our case replicates the antigenic composition of the glomerulus, but the positivity for CK 18 in our case does not support this assumption [14]. Well-differentiated and poorly differentiated follicular cell-derived carcinomas are positive for low-molecular-weight CKs [1].…”

Thyroid transcription factor-1 expression in endometrioid tumors: a note of caution

“…1A, B), in some morule-lacking adenocarcinomas of the gallbladder, in morules in cyclic endometrium and endometrial hyperplastic lesions [3], and in a group of tumors containing morules with cells displaying biotin-rich optically clear nuclei (BROCN; BROCN-family tumors), which includes endometrioid endometrial adenocarcinomas (Figs. 1C-E), ovarian endometrioid tumors, and others [4]. For these reasons, we think that caution should be applied in the interpretation of the article by Fujiwara et al [1] and in others [5] that reported TTF1 immunoreactivity in tumors other than those originating in the lung or thyroid and that used both antigen retrieval and/or avidin-biotin peroxidase complex methods.…”

“…For these reasons, we think that caution should be applied in the interpretation of the article by Fujiwara et al [1] and in others [5] that reported TTF1 immunoreactivity in tumors other than those originating in the lung or thyroid and that used both antigen retrieval and/or avidin-biotin peroxidase complex methods. Chiarelli et al [3] have demonstrated that CD10 is a useful immunomarker of morules in endometrioid lesions of the female genital tract, and most recently, our group [4] evidenced that CD10 can also be useful in identifying morules in the BROCN-family tumors, all sharing alterations in the APC/β-catenin pathway. In fact, we believe the lesion depicted in Fig.…”

“…We also think that the association of TTF1 expression with better prognosis in patients with ovarian cancer reported by Fujiwara et al [1] is related to the molecular alterations involved in the development of neoplasms containing morules with cells displaying biotin-rich nuclei. These neoplasms have a permanent activation of the APC/β-catenin pathway [4], and some studies have shown that β-catenin abnormalities are strongly associated with low-grade endometrioid ovarian carcinoma [7].…”