A case of epibulbar osseous choristoma with review of literature

Choristoma: a very rare cause of thyroid nodule. Case report and literature review

BACKGROUND

Choristoma is a well-defined benign lesion formed by histologically normal tissue in an unusual location. Diagnosis is confirmed after surgical removal of the mass. To our knowledge, to date there has been only one case of thyroid choristoma described in the literature.

PATIENT FINDINGS

A 70-year-old man with a history of non-Hodgkin lymphoma presented with sudden cervical enlargement. Cervical CT scan showed a 47mm hypodense nodule on the right thyroid lobe. Fine-needle aspiration revealed follicular lesion of undetermined significance. During the following weeks there was noticeable thyroid enlargement. Reassessment with thyroid ultrasound showed a 73mm nodule. The patient underwent total thyroidectomy. Histopathological examination revealed a choristoma composed of squamous epithelium lined cysts, smooth muscle, adipose tissue, connective tissue, foci of ossification and extramedullary hematopoiesis. No cytological atypia or tumoral necrosis were found. Thyroid choristomas are an exceedingly rare cause of a thyroid nodule.

Epibulbar osseous choristoma: a case report

Peribulbar osseous choristoma is a benign, solid nodule; it is a subtype of epibulbar choristomas (belongs to single tissue choristomas), consisting of pure bony tissues. Epibulbar osseous choristoma is the rarest subtype of epibulbar choristomas, with only 65 cases reported since the mid-19th century; so, the rarity of the disease drove me to report it. A 7-year-old female presented with a painless left ocular superotemporal mass, which was present since birth and located under the conjunctiva. The primary diagnoses included lipodermoid and subconjunctival foreign bodies. Ocular interventions included a B-scan, examination under anesthesia and surgical excision of the mass in toto, and the histopathological examination showed that it was an osseous choristoma.

Epibulbar Osseous Choristoma: A Rare Find in the Superior Conjunctival Tarsal Plate of the Upper Eyelid

A 37-year-old male was found to have a firm yellowy-white palpable mass embedded within the conjunctival surface of the tarsal plate of the left upper eyelid. This was asymptomatic and noted on a routine examination for contralateral epiphora. An excisional biopsy was performed and a "rock-like nodule" was removed with histopathology confirming the presence of mature bone. While the literature describes these lesions located in other aspects of the orbit, this is the first described case of an epibulbar osseous choristoma located in the tarsal plate of the upper eyelid.