Lymphoplasmacyte-rich meningioma with hematologic signs and PD-L1 over-expression.

Lymphoplasmacyte-rich meningioma (LPRM) is one of the rarest variants of grade I meningiomas. It can be clinically associated with prominent peripheral blood abnormalities, anemia, and/or various gammopathy, which usually disappear after surgical removal of the tumor. We document a case of right frontal LPRM in a 72-year-old male who presented general cognitive decadence. The patient suffered from mild anemia. The LPRM is a rare variant of meningioma, with only a few cases globally reported in the literature. It has been categorized as a grade I tumor in the 2021 World Health Organization (WHO) classification central nervous system. Due to the rarity, this meningioma variant origin and biological behavior are still not clear. Immunohistochemistry profile showed prominent PD-L1 expression, leading to additional interrogation on LPRM immunomorphological characteristics, the significance of the inflammatory tumoral microenvironment and its correlation with the immune-checkpoints.

Spread of hyperplastic pulmonary neuroendocrine cells into air spaces (S.H.I.P.M.E.N.T.S): A proof for artifact.

OBJECTIVES: Spread through air spaces (STAS) is a recently proposed invasion way of lung cancer, including neuroendocrine (NE) neoplasms. However, if this phenomenon is a real one or an artifact while manipulating lung specimens, it is still matter of debate. MATERIAL AND METHODS: Three consecutive patients with newly diagnosed diffuse idiopathic pulmonary NE cell hyperplasia (DIPNECH) were reviewed for STAS. RESULTS: In well-fixed lung specimens, DIPNECH was seen to coexist with atypical carcinoid, bifocal typical carcinoid and adenocarcinoma in the three patients, respectively. While STAS was not observed at the growing edges of tumors, a few freely-floating aggregates of hyperplastic NE cells within air spaces were noticed to emanate from foci of NE hyperplasia and tumorlets and in intimate association with normal bronchiolar cells and erythrocytes to denote artifactual derivation upon tissue manipulation. CONCLUSIONS: Traveling of hyperplastic NE cells through air spaces is likely to artifactually occur via knife, surgeon or other way, thus challenging invasion by STAS.

Lymphoplasmacyte-rich meningioma with hematologic signs and PD-L1 over-expression

ABSTRACT Lymphoplasmacyte-rich meningioma (LPRM) is one of the rarest variants of grade I meningiomas. It can be clinically associated with prominent peripheral blood abnormalities, anemia, and/or various gammopathy, which usually disappear after surgical removal of the tumor. We document a case of right frontal LPRM in a 72-year-old male who presented general cognitive decadence. The patient suffered from mild anemia. The LPRM is a rare variant of meningioma, with only a few cases globally reported in the literature. It has been categorized as a grade I tumor in the 2021 World Health Organization (WHO) classification central nervous system. Due to the rarity, this meningioma variant origin and biological behavior are still not clear. Immunohistochemistry profile showed prominent PD-L1 expression, leading to additional interrogation on LPRM immunomorphological characteristics, the significance of the inflammatory tumoral microenvironment and its correlation with the immune-checkpoints.