Fibromyxoid Nephrogenic Adenoma
\nA Series of 43 Cases Reassessing Predisposing Conditions, Clinical Presentation, and Morphology JAN. 2023<\/p>\n
FREE LINK<\/strong> Li, Lin MD, PhD*; Williamson, Sean R. MD†; Castillo, Rosa P. MD‡,§; Delma, Katiana S. HT*; Gonzalgo, Mark L. MD, PhD§,∥; Epstein, Jonathan I. MD¶,#,**; Kryvenko, Oleksandr N. MD*,§,∥,††<\/p>\n The American Journal of Surgical Pathology. 47(1):37-46, January 2023.<\/p>\n Précis<\/u> Comment<\/u> The occurrence of FM-NA in various sites along the whole urinary system, as well as the low rate of lesions linked to prior irradiation are novel findings, as compared to previous reports. The main observation of this study is that FM-NA seem to show an increased predilection for the extension to deeper tissues beyond lamina propria, which can mimic an infiltrating neoplasm. This observation is supported by two further reports of FM-NAs of the ureter, located in the muscularis propria (10.33719\/yud.2021;16-2-747110), and the perinephric adipose tissue (10.1097\/PAS.0b013e31826f0447); in the latter, focal FM morphology was seen within a classic NA.<\/p>\n Interestingly, the authors report the occurrence of pure FM morphology in more than one third of all cases (35%), which can make the diagnosis of FM-NA even more difficult. The issue of differential diagnosis of FM-NA is of pivotal importance in routine practice, since this entity may morphologically resemble mucinous carcinoma, prostate carcinoma, chordoid urothelial carcinoma, and amyloidosis, in the various locations, and the large size attained by some lesions may further suggest a malignancy at radiology. As pointed out by the authors, the use of a proper histochemical\/immunohistochemical panel along with available information on previous history of urothelial injury are helpful in clinching the diagnosis. In this setting, the fact that the FM component of the lesion, unlike conventional NA, lacks Napsin A staining, should be taken into account.<\/p>\n Reviewed by: Francesca Sanguedolce, MD PhD<\/p>\n<\/body><\/html>\n","protected":false},"excerpt":{"rendered":" Fibromyxoid Nephrogenic Adenoma A Series of 43 Cases Reassessing Predisposing Conditions, Clinical Presentation, and Morphology JAN. 2023 FREE LINK https:\/\/journals.lww.com\/ajsp\/Fulltext\/2023\/01000\/Fibromyxoid_Nephrogenic_Adenoma__A_Series_of_43.4.aspx Li, Lin MD, PhD*; Williamson, Sean R. MD†; Castillo, Rosa P. MD‡,§; Delma, Katiana S. HT*; Gonzalgo, Mark L. MD, PhD§,∥; Epstein, Jonathan I. MD¶,#,**; Kryvenko, Oleksandr N. MD*,§,∥,†† The American Journal of Surgical Pathology. … Continue reading FIRST QUARTER OF 2023<\/span>
\nhttps:\/\/journals.lww.com\/ajsp\/Fulltext\/2023\/01000\/Fibromyxoid_Nephrogenic_Adenoma__A_Series_of_43.4.aspx<\/p>\n
\nThe authors performed a multicenter retrospective cohort study, reviewing the morphological and clinical data of 43 cases of fibromyxoid nephrogenic adenoma (FM-NA) from 42 patients. Patients’ median age was 72 years (range, 31-94 yrs), and the most common sites were the bladder, prostate\/prostatic urethra, kidney, ureter, penile urethra, and urethral diverticulum, in decreasing order. Predisposing conditions, including endoscopic\/surgical procedures, were present in the vast majority of patients with information (36\/37), and 4\/37 had a history of prior irradiation. Most FM-NAs extended beyond the lamina propria in their respective sites, involving the prostatic stroma, renal sinus or perinephric fat, muscularis propria of the bladder or renal pelvis, and corpus spongiosum. PAX8 and Napsin A were positive and negative in all examined cases, respectively; the latter stained only the classic NA component, if present.<\/p>\n
\nThis is the largest series of FM-NA reported so far. NA has variable morphological patterns (mostly tubular, papillary, and flat), few of them usually occurring in the same case, which is a clue to a sometimes challenging diagnosis. As a variant of NA, FM-NA stands out for the unique presence of changes involving the stroma surrounding the epithelial structures. When first described in 2007, it was suggested that such stromal changes were iatrogenic, or, to a lesser extent, result from excessive mucin secretion. Herein, on the basis of the provided clinical information, the authors favor the first hypothesis.<\/p>\n