Ainhoa Ordoñez Arrillaga

Dr. Ainhoa Ordoñez Arrillaga

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Research Focus & Metrics

Academic Career Length

1Year (2026-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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25 August 2026 in The American Journal of Dermatopathology
Verified
Journal Article
Closed access
JFJose Fuentes-Ros
Jose Fuentes-Ros
AAAinhoa Ordoñez Arrillaga
Ainhoa Ordoñez Arrillaga
JCJulia Castro-Martín
Julia Castro-Martín
JPJesús Pinto
Jesús Pinto
LRLuis Requena
Luis Requena
ÁSÁngel Santos-Briz
Ángel Santos-Briz
Perineal nodular induration (PNI), also known as cyclist's nodule, is an uncommon reactive pseudotumoral lesion related to repetitive mechanical trauma in saddle sports. Although clinically recognized, its histopathologic spectrum remains incompletely characterized. We performed a retrospective dermatopathologic study of 8 cases of PNI independently reviewed by 2 experienced dermatopathologists using conventional microscopy and digital slide imaging. The study included 7 men and 1 woman, with a median age of 48.5 years (range, 34–76 years). All cases showed a poorly circumscribed fibrohyaline proliferation centered within the deep dermis and subcutaneous tissue. Consistent findings included marked stromal hyalinization, rounded hyalinized collagen nodules, septal remodeling, adipose tissue entrapment, low cellularity, bland spindle cells, and vasculolymphatic dilatation. Significant cytologic atypia, mitotic activity, pseudocyst formation, and neural hyperplasia were absent in all cases. Rounded hyalinized collagen nodules were identified in all cases, and although previous reports describe stromal hyalinization and dense collagen deposition, this nodular collagenous pattern has not been specifically emphasized. Immunohistochemical studies, performed in 2 cases, were nonspecific and overlapped with previously reported profiles. Orcein staining, performed in 2 cases, demonstrated marked reduction or near-complete absence of elastic fibers in both specimens. Our findings suggest that PNI exhibits a reproducible fibrohyaline pattern that may facilitate recognition on routine hematoxylin–eosin sections in the appropriate clinicopathologic setting and may reduce the need for ancillary immunohistochemical studies in selected cases.