An Unusual Combination of Neurological Manifestations and Sudden Vision Loss in a Child with Familial Hyperphosphatemic Tumoral Calcinosis

Optic nerve and choroidal calcification in pediatric neurofibromatosis type 2

We describe a teenage boy with gradually progressive blurred vision in right eye. He could appreciate hand motions in the right eye and 20/20 vision in the left eye. Ophthalmic examination revealed bilateral optic atrophy with yellow-white peri-papillary lesion in the right eye. Computed Tomography (CT) brain and orbit showed choroidal, optic nerve and intracranial calcifications. The Magnetic resonance (MR) imaging showed the calcification selectively involved the optic nerve sheath with no abnormal hyperintensity or enhancement of the optic nerve substance, suggestive of a bilateral optic nerve sheath meningioma. The work-up for metastatic calcification was normal. The molecular genetic testing revealed a heterozygous, missense variant in NF2 (c.784C > G, p. Arg262Gly) gene, which segregated in the proband's mother. This variant is not reported in the literature and adds to the genotype of Neurofibromatosis Type 2. To preserve the vision in left eye, the child underwent external beam radiotherapy (EBRT). The vision and fields in the left eye are stable after EBRT at a two-year follow-up. This case highlights the systematic approach to a case of optic atrophy in a child and identifying the rare etiology of optic nerve calcification with a report of novel variant in NF2 gene.

Clinical Characteristics, Therapeutic Options, and Outcomes in Hyperphosphatemic Tumoral Calcinosis: A Systematic Review

This systematic review was performed to understand better the myriad presentations, various therapeutic options, response to therapy, and its clinical outcomes in hyperphosphatemic tumoral calcinosis (HTC). Full texts were selected according to strict inclusion criteria. All case reports of HTC wherein baseline phosphate was measured, treatment offered was mentioned, and information on follow-up and response to therapy that were available were included. A total of 43 of 188 eligible studies (N = 63 patients) met the inclusion criteria. A list of desired data was extracted and graded for methodological quality. A total of 63 individuals (Males = 33) were included from the 43 eligible case studies. The median age of the patients was 18 (IQR 8-32) years. The most frequently involved sites were the hip/gluteal region (34/63; 53.9%) followed by the elbow/forearm (26/63; 41.2%), and the shoulder (18/63; 28.5%). Three patients had conjunctival calcific deposits. The mean (SD) phosphate was 6.9 (1.1) mg/dL. Among the subjects, 36/63 (57.1%) underwent surgical excision with some form of medical therapy. Two patients underwent only surgical excision (2.1%). One patient was maintained on follow-up (1.6%) and 24/63 (38.1%) patients were treated with medical measures. The median (IQR) follow-up duration was 3 (1-9) years. Regression or reduction in lesion size was reported in 19/63 (30.2%) subjects; 20/63 (31.7%) showed progression, 24/63 (38.1%) had features of stable disease, and mortality was reported in 3 patients (4.7%). We report for the first time a detailed description of the clinical and therapeutic response of HTC. A combination of medical measures aimed at lowering serum phosphate appears to be the cornerstone of treatment, although clinical responses may vary.

Recurrent Bilateral Lower Motor Neuron Type of Facial Palsy with Hearing Impairment: Hyperphosphatemic Familial Tumoral Calcinosis

Hyperphosphatemic familial tumoral calcinosis (HFTC) presents with varied neurological manifestations that have been reported in the literature like facial palsy, vision and hearing impairment, stroke, and headache. In this article, we reported a 12-year-old girl child patient with recurrent facial weakness with bilateral hearing impairment and multiple ulcerative lesions on lower limbs and elbows. On examination, she had lower motor neuron (LMN) facial palsy with conductive hearing loss. The investigations showed hyperphosphatemia (9.3 mg/dL) with normal serum calcium (10.4 mg/dL), alkaline phosphatase (147.9 U/L), parathyroid hormone (23.12 pg/mL), and renal function tests. Elevated serum calcium and phosphorus product (96.72 mg 2 /mL 2 ) and elevated renal tubular reabsorption of phosphate (TMPxGFR) value (9.16) were noted. Skeletal survey showed hyperostosis in the long bone diaphysis, vertebrae, ribs, pelvic bone, skull, and facial bones with narrowing of cranial ostium, characteristically without any peri-articular soft tissue calcifications. An angiogram showed multiple intravascular calcifications. She was managed with a low-phosphate diet, sevelamer, niacinamide, acetazolamide, sucroferric oxyhydroxide to lower serum phosphate level, and topical sodium thiosulfate ectopic cutaneous calcification. Exome sequencing showed novel homozygous inframe deletion of ACG in FGF23 gene exon 3 at c.374_376 delins position (p. Asp125del) in the proband and a mutation in the heterozygous state in the mother and elder sibling, thus confirming a molecular diagnosis of HFTC. Our case had a unique neurological presentation of recurrent bilateral lower motor nerve facial palsy, hearing loss, multiple ectopic cutaneous calcifications without peri-articular deposits, multiple intravascular, intracranial, and vertebral endplate calcification, which has not been reported earlier. The proband showed a novel pathogenic variant suggesting an expanding phenotype of HFTC.