A diagnostic immunohistochemical panel for yolk sac (primitive endodermal) tumours based on an immunohistochemical comparison with the human yolk sac

Abstract

CPs reproduce the immunophenotype of HYS and early endoderm with variable expression of both AFP and markers of early gut or hepatic differentiation. SGPs with intestinal differentiation often have incomplete immunophenotypes. A differential diagnosis panel, including both markers of pluripotentiality (SALL4 and/or LIN28) and endoderm (AFP, GPC3 and villin), is proposed. It identifies overlapping multidifferentiation of primitive and somatic immunophenotypes, supporting the recently proposed term of primitive endodermal tumours.

Diagnostic markers for germ cell neoplasms: from placental-like alkaline phosphatase to micro-RNAs

“…Yolk sac tumour produces and secrets a-fetoprotein (AFP), which is detectable in serum and tumour tissue [66]. Among other immunohistochemical markers for yolk sac tumour the most informative are Glypican-3 (GPC3) and SALL4 [65,67,68] (Figure 3). Choriocarcinoma contains trophoblastic-like syncytia and secrets b-chorio-gonadotrophin (b-hCG) which is measurable in serum and detectable in tissues [66].…”

Testicular Germ Cell Tumors

“…Villin, glypican-3, SALL4, and low-molecular-weight keratins are often positive (Fig. 7.20) [82,136,137]. Rarely, c-KIT, SOX2, PLAP, and podoplanin positivity may be seen in YST [138].…”

“…OCT4 and CD30 are negative. Hep-Par-1 reactivity has been documented in areas with or without hepatoid differentiation [136].…”

Unusual Presentations of Gynecologic Tumors: Extragonadal Yolk Sac Tumor of the Vulva

“…6,[18][19][20][21][22][23][24][25][26][27][28][29][30] There are several theories regarding the histogenesis of extragonadal yolk sac tumor, including (1) arrested migration of or misplaced germ cells during embryogenesis, (2) reverse migration of germ cells, (3) abnormal differentiation of somatic cells, (4) derivation from pluripotential stem cells within a somatic tumor, (5) origination from residual fetal tissue following incomplete abortion (for primary endometrial yolk sac tumor), and (6) metastasis from an occult gonadal primary. 1,4,5,21,25 The association with somatic tumors such as endometrioid adenocarcinoma or carcinosarcoma, seen in some cases arising in the gynecologic tract of older patients, supports a non-germ cell origin (points 3, 4) for a subset of extragonadal yolk sac tumors. 1 However, in the case of yolk sac tumor primary in the vulva, misplaced/aberrant germ cell migration along the gubernaculum is the leading hypothesis.…”

“…1,4,5,21,25 The association with somatic tumors such as endometrioid adenocarcinoma or carcinosarcoma, seen in some cases arising in the gynecologic tract of older patients, supports a non-germ cell origin (points 3, 4) for a subset of extragonadal yolk sac tumors. 1 However, in the case of yolk sac tumor primary in the vulva, misplaced/aberrant germ cell migration along the gubernaculum is the leading hypothesis. 24 Whether of germ cell or somatic origin, yolk sac tumors may display a variety of patterns that resemble both endodermal extraembryonic and somatic patterns, including (1) reticular/microcystic pattern, characterized by a loose meshwork of anastomosing, small cystic spaces lined by flattened, primitive cells; (2) pseudopapillary, labyrinth, tubular, and ''festoon'' patterns, the latter characterized by interconnecting cords of cells with a drapelike arrangement; gastrointestinal or endometrial carcinomas; (7) hepatoid pattern; and (8) solid pattern.…”