Table of Contents
Definition / general | Essential features | Epidemiology | Sites | Clinical features | Prognostic factors | Case reports | Treatment | Microscopic (histologic) description | Microscopic (histologic) images | Positive stains | Negative stains | Differential diagnosis | Additional referencesCite this page: Andeen NK, Tretiakova M. Plasmacytoid. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/kidneytumormalignanturothelialcarcinomasubtypesplasma.html. Accessed January 16th, 2021.
Definition / general
- Resembles plasma cell infiltrate with sheets of discohesive cells with eosinophilic cytoplasm, eccentrically placed nuclei, inconspicuous nucleoli
- High grade by definition
- May be pure or coexist with different patterns of urothelial carcinoma
Essential features
- Discohesive sheets or single cells with plasmacytoid appearance, often mimicking inflammatory process but is high grade and has poor prognosis
- Do not use CD138 in isolation to distinguish from plasma cells
Epidemiology
- 63 - 75 years of age
- M > F
Sites
- Renal pelvis
- Also bladder, ureter
Clinical features
- Advanced stage at presentation, poor prognosis (Mod Pathol 2009;22:S96, Mod Pathol 2006;19:494)
Prognostic factors
- Plasmacytoid variant has uniformly poor prognosis (Mod Pathol 2009;22:S96)
Case reports
- 75 year old man with high grade urothelial carcinoma, plasmacytoid variant (Pol J Pathol 2014;65:237)
- Clinical course of plasmacytoid urothelial carcinoma of the upper urinary tract (Urol Int 2012;89:120)
Treatment
- Resection, chemotherapy, potentially radiation
Microscopic (histologic) description
- Resembles plasma cell infiltrate, often within a loose, myxoid stroma
- Has single and sheet-like growth of discohesive cells with eosinophilic cytoplasm, eccentrically placed round nuclei
- May contain focal intracytoplasmic lumina (Adv Anat Pathol 2008;15:218)
Microscopic (histologic) images
Positive stains
- AE1 / AE3, CK7, CAM 5.2, EMA, uroplakin III, p63, p40, variable CK20
- Frequently expresses CD138 (Mod Pathol 2009;22:S96, Int J Clin Exp Pathol 2012;5:601)
Negative stains
- CD45, MUM1, B and T cell markers, S100, MelanA, desmin, myogenin, MyoD1 (Arch Pathol Lab Med 2007;131:1244), CDX2, villin, ER, GCDFP15
- May be E-cadherin negative or positive (Int J Clin Exp Pathol 2012;5:601)
Differential diagnosis
- Inflammatory process:
- At low power, plasmacytoid variant of urothelial carcinoma may have loose myxoid stroma with scattered infiltrate
- Higher power shows atypical, cytokeratin+ neoplastic cells
- Lymphoma: A panel including hematopoietic markers can help exclude this: CD45, B and T cell markers
- Melanoma: positive for S100, MelanA, MITF, HMB45 vs. plasmacytoid variant which lacks these markers
- Metastatic carcinoma, particularly breast lobular carcinoma or gastric adenocarcinoma: clinical history and a panel of site specific markers help distinguish
- Paraganglioma positive for synaptophysin and chromogranin with S100+ sustentacular cells, vs. plasmacytoid variant which lacks these cells and is also cytokeratin negative
- Plasma cell neoplasms: have light chain restriction, lack strong diffuse expression of specific cytokeratins such as CAM 5.2 or CK7 and are more likely to express MUM1, CD56 or cyclin D1 (if they have t(11;14))
- Note: CD138 is expressed in most plasma cell neoplasms and plasmacytoid variant of urothelial carcinoma, and should not be used in isolation to distinguish
- Rhabdomyosarcoma: Expresses desmin, myogenin, myoD1, vs. plasmacytoid variant which is negative for these markers
Additional references