Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Case Reports
. 2024 Oct 2;16(10):e70721.
doi: 10.7759/cureus.70721. eCollection 2024 Oct.

Phosphaturic Mesenchymal Tumor of the Greater Trochanter: A Case Report

José Pablo Bibiloni Lugo  1 , Hector A Muñoz-Miró  2 , Rafael Fernandez-Soltero  1 , Norman Ramírez-Lluch  3 , Juan Bibiloni  4
Affiliations
Case Reports

Phosphaturic Mesenchymal Tumor of the Greater Trochanter: A Case Report

José Pablo Bibiloni Lugo et al. Cureus. .

Abstract

This is the case of a 56-year-old Hispanic male with a history of multiple fractures and electrolyte abnormalities, including hypophosphatemia and phosphaturia. Physical examination, imaging studies, and laboratory workup may have suggested the presence of a phosphaturic mesenchymal tumor (PMT) causing osteomalacia. The patient underwent surgery for en bloc tumor removal, and the histopathological analysis confirmed the presence of neoplastic cells consistent with PMT with minimal immunohistochemical positivity to S100 protein, which is atypical for this type of tumor. This case highlights the challenges in diagnosing PMTs due to their rarity and variable presentation. It emphasizes the importance of considering PMT in the differential diagnosis for unexplained hypophosphatemia and osteomalacia-like symptoms, especially in persistent disease after parathyroidectomy for presumed primary hyperparathyroidism. The atypical immunohistochemical profile observed in this case contributes to the growing body of knowledge about the heterogeneity of PMTs and underscores the need for comprehensive diagnostic approaches in suspected cases.

Keywords: hypophosphatemia; phosphaturia; phosphaturic mesenchymal tumor; s100 protein; tumor induced osteomalacia.

PubMed Disclaimer

Conflict of interest statement

Human subjects: Consent was obtained or waived by all participants in this study. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work.

Figures

Figure 1
Figure 1. Left knee lateral (A) and AP (B) X-ray. Proximal tibia fracture was also present upon presentation.
Figure 2
Figure 2. Three-phase technetium bone scan. Demonstrated costal rachitic rosary sign, a typical finding in patients with osteomalacia.
Figure 3
Figure 3. Whole body SPECT/CT. Coronal, sagittal, and transaxial CT (A, B, C) demonstrated an ill-defined irregular area of sclerosis in the intramedullary aspect of the right femur, in the region of the greater trochanter. Coronal, sagittal, and transaxial SPECT CT (D, E, F) show an area of increased uptake in the right femur greater trochanter. The fused SPECT/CT image (G, H, I) accurately establishes a correlation between the area of focal sclerosis observed on CT with the area of increased uptake observed on SPECT.
SPECT: single photon emission computed tomography
Figure 4
Figure 4. Whole body octreoscan anterior (A) and posterior (B) view. Small somatostatin receptor-rich lesion in the intramedullary aspect of the right femoral greater trochanter.
Figure 5
Figure 5. Histological analysis of this tumor revealed a richly vascular spindle cell neoplasm with bland cytology and rich vasculature.
See this image and copyright information in PMC

References

    1. Phosphaturic mesenchymal tumors: a review and update. Folpe AL. https://doi.org/10.1053/j.semdp.2019.07.002. Semin Diagn Pathol. 2019;36:260–268. - PubMed
    1. Phosphaturic mesenchymal tumors: rethinking the clinical diagnosis and surgical treatment. Liu Y, He H, Zhang C, Zeng H, Tong X, Liu Q. https://doi.org/10.3390/jcm12010252. J Clin Med. 2022;12:252. - PMC - PubMed
    1. Phosphaturic mesenchymal tumor (PMT): exceptionally rare disease, yet crucial not to miss. Ghorbani-Aghbolaghi A, Darrow MA, Wang T. https://doi.org/10.4322/acr.2017.031. Autops Case Rep. 2017;7:32–37. - PMC - PubMed
    1. 'Rachitic rosary sign' and 'tie sign' of the sternum in tumour-induced osteomalacia. Chakraborty PP, Bhattacharjee R, Mukhopadhyay S, Chowdhury S. https://doi.org/10.1136/bcr-2016-214766 BMJ Case Rep. 2016;2016:0. - PMC - PubMed
    1. Clinical, histopathologic, subtype, and immunohistochemical analysis of jaw phosphaturic mesenchymal tumors. Li D, Zhu R, Zhou L, Zhong D. https://doi.org/10.1097/MD.0000000000019090 Medicine (Baltimore) 2020;99:0. - PMC - PubMed

Publication types

LinkOut - more resources