Co-administration of Systemic and Intralesional Zoledronic Acid in a Case of Fibrous Dysplasia: A Potentially Novel Therapy

Non-biological Antiresorptive: Bisphosphonates

Background

Bisphosphonates, synthetic analogs of endogenous pyrophosphates, are pivotal in managing various bone disorders, primarily osteoporosis, which affects millions globally. While osteoporosis, especially postmenopausal osteoporosis, significantly benefits from bisphosphonate therapy, considerations arise regarding their administration and potential side effects.

Clinical application of Bisphosphonates

Bisphosphonates, divided into nitrogen-containing and non-nitrogenous groups, exert their influence through distinct mechanisms, with the former being notably more potent. The role of bisphosphonates in other diseases, such as Paget's bone and skeletal metastasis disease is also discussed. Detailed information on the administration routes, dosage regimens, and considerations for drug holidays is provided. The article navigates through the chemical structure, generations, and mechanism of action of bisphosphonates. The article covers administration routes, dosage regimens, and drug holidays, in addition to discussing potential adverse effects and contraindications.

Conclusions

Bisphosphonates hold an unrivaled legacy in the management of osteoporosis. The ubiquitous availability and the cost-effectiveness of these time-tested medications make them an invaluable asset in the osteoporosis treatment landscape, especially in developing nations like India.

A Rare Case of a Primary Leiomyoma of the Clivus in an Immunocompetent Patient and a Review of the Literature Regarding Clival Lesions

Leiomyomas are common lesions that are usually located in the genitourinary and gastrointestinal tracts. Primary leiomyomas at the skull base are uncommon. They are composed of well-differentiated smooth muscle cells without cellular atypia. The diagnosis of a leiomyoma has to be confirmed by immunohistochemistry. The tumor tissue is immunoreactive for SMA, S100 and cytokeratin. Leiomyomas mainly occur in immunocompromised patients. Most tumor tissues are positive for EBV. The presented case is that of a 56-year-old immunocompetent woman with a tumor on the clivus. The radiological images suggested chordoma or fibrous dysplasia. Transnasal transsphenoidal surgery was performed. The tumor tissue consisted of well-differentiated smooth muscle cells with elongated nuclei. Immunohistochemistry revealed a positive reaction for desmin, SMA and h-Caldesmon and a negative reaction for S100, beta-catenin, PGR and Ki67. The leiomyoma diagnosis was subsequently established. To the best of our knowledge, the case of a primary leiomyoma on the clivus of an immunocompetent patient is the first to be described. We also extensively reviewed the literature on the immunohistopathological and radiological differential diagnosis of clival lesions.

Bilateral Dysplastic Gangliocytoma with Concurrent Polyostotic Fibrous Dysplasia: A Case Report and Literature Review

BACKGROUND

Dysplastic gangliocytoma is a sporadic cerebellar benign tumor with the characteristics of hamartoma and true tumor, also known as Lhermitte-Duclos disease (LDD). Bone fibrous dysplasia (FD) is a slowly progressive self-limited benign bone tissue disease. Cowden syndrome, an autosomal dominant genetic disorder caused by germline mutations in the PTEN gene, is considered to be closely related to dysplastic gangliocytoma. McCune-Albright syndrome is a disease characterized by café-au-lait skin macules, polyostotic FD, and precocious puberty. The etiologic mechanism of both conditions is not yet clear. We report a rare case of bilateral dysplastic gangliocytoma with concurrent polyostotic FD.

CASE DESCRIPTION

We describe a 16-year-old boy with both LDD and FD. He presented for medical examination with headache and poor eyesight. Magnetic resonance imaging revealed proliferation of the skull and abnormal signals in the cerebellum, and supratentorial hydrocephalus. Subtotal resection of the cerebellar tumor was performed, and the diagnosis of LDD and FD was confirmed by histopathology. No other abnormal changes were found in systemic medical examination and no PTEN gene mutation was found in the genetic analysis; therefore, the diagnoses of Cowden syndrome and McCune-Albright syndrome were excluded.

CONCLUSIONS

LDD and FD are 2 rare diseases, and the simultaneous occurrence of the 2 conditions has not been reported before, to our knowledge. Our report challenges the etiology of the 2 diseases and the relationship between them, hoping to provide a reference for the study of the 2 diseases.