Your browser doesn't support javascript.
loading
Phosphaturic mesenchymal tumor (PMT): exceptionally rare disease, yet crucial not to miss
Ghorbani-Aghbolaghi, Amir; Darrow, Morgan Angus; Wang, Tao.
  • Ghorbani-Aghbolaghi, Amir; University of California. Davis. Department of Pathology, Laboratory Medicine. Sacramento. US
  • Darrow, Morgan Angus; University of California. Davis. Department of Pathology, Laboratory Medicine. Sacramento. US
  • Wang, Tao; University of California. Davis. Department of Pathology, Laboratory Medicine. Sacramento. US
Autops. Case Rep ; 7(3): 32-37, July.-Sept. 2017. ilus, tab
Article in English | LILACS | ID: biblio-905318
ABSTRACT
Phosphaturic mesenchymal tumors (PMTs) are very rare tumors which are frequently associated with Tumor Induced Osteomalacia (TIO), a paraneoplastic syndrome that manifests as renal phosphate wasting. The tumor cells produce a peptide hormone-like substance known as fibroblast growth factor 23 (FGF23), a physiologic regulator of phosphate levels. FGF23 decreases proximal tubule reabsorption of phosphates and inhibits 1-α-hydroxylase, which reduces levels of 1-α, 25-dihydroxyvitamine D3. Thus, overexpression of FGF23 by the tumor cells leads to increased excretion of phosphate in the urine, mobilization of calcium and phosphate from bones, and the reduction of osteoblastic activity, ultimately resulting in widespread osteomalacia. Patients typically present with gradual muscular weakness and diffuse bone pain from pathologic fractures. The diagnosis is often delayed due to the non-specific nature of the symptoms and lack of clinical suspicion. While serum phosphorus and FGF23 testing can assist in making a clinical diagnosis of PMT, the responsible tumor is often difficult to locate. The pathologic diagnosis is often missed due to the rarity of PMTs and histologic overlap with other mesenchymal neoplasms. While patients can experience severe disabilities without treatment, excision is typically curative and results in a dramatic reversal of symptoms. Histologically, PMT has a variable appearance and can resemble other low grade mesenchymal tumors. Even though very few cases of PMT have been reported in the world literature, it is very important to consider this diagnosis in all patients with hypophosphatemic osteomalacia. Here we present a patient who suffered for almost 5 years without a diagnosis. Ultimately, the PMT was located on a 68Ga-DOTA TATE PET/CT scan and subsequently confirmed by histologic and immunohistologic study. Interestingly, strong positivity for FGFR1 by IHC might be related to the recently described FN1-FGFR1 fusion. Upon surgical removal, the patient's phosphate and FGF23 levels returned to normal and the patient's symptoms resolved.
Subject(s)


Full text: Available Index: LILACS (Americas) Main subject: Bone Neoplasms / Neoplasms, Connective Tissue Type of study: Diagnostic study Limits: Humans / Male Language: English Journal: Autops. Case Rep Journal subject: Anatomia / Patologia Cl¡nica / Patologia Legal Year: 2017 Type: Article Affiliation country: United States Institution/Affiliation country: University of California/US

Similar

MEDLINE

...
LILACS

LIS


Full text: Available Index: LILACS (Americas) Main subject: Bone Neoplasms / Neoplasms, Connective Tissue Type of study: Diagnostic study Limits: Humans / Male Language: English Journal: Autops. Case Rep Journal subject: Anatomia / Patologia Cl¡nica / Patologia Legal Year: 2017 Type: Article Affiliation country: United States Institution/Affiliation country: University of California/US