Benign peripheral nerve sheath tumors (neurofibromas) of the lacrimal gland

Adenoid cystic carcinoma of the palpebral lobe of the lacrimal gland - case report and literature review

Epithelial tumors of the lacrimal gland are rare and usually develop in the orbital lobe. We report the exceedingly rare occurrence of a primary adenoid cystic carcinoma in the palpebral lobe of the lacrimal gland. A 26-year-old female was referred for evaluation of a gradually enlarging mass in the lateral upper eyelid, previously diagnosed as a chalazion. Computed tomography revealed a heterogeneous round lesion anterior to the orbital rim. Excisional biopsy was compatible with an adenoid cystic carcinoma. After excluding distant metastasis, and as the patient refused adjuvant radiotherapy, a second surgical procedure, with wide local excision, was indicated. Follow-up showed no recurrence. This case highlights the importance of performing a thorough clinical examination when diagnosing any lateral upper eyelid mass. A high index of suspicion for malignant tumors of the lacrimal gland should always be maintained, and a complete excision with histological analysis should be preferred whenever possible.

Imaging of the Lacrimal Gland

The lacrimal gland is situated superolateral to the eye and produces tears that moisten, lubricate, and protect the delicate corneal and conjunctival epithelium. Anatomically related to the orbit but embryologically and functionally more closely related to the salivary glands, radiological imaging has proven invaluable in delineation and differentiation of the unique range of pathological processes affecting the lacrimal gland. This article details traditional and new imaging techniques used in investigating such pathology and discusses the imaging findings and patterns of spread characteristic of various neoplastic, inflammatory, and structural processes ranging from benign adenomas, adenocarcinomas, and lymphomas to sarcoidosis, Mickulicz's syndrome, histiocytosis, and benign dacrocysts.

A corneal diffuse neurofibroma as a manifestation of von recklinghausen disease

PURPOSE

To report a case of a primary corneal diffuse neurofibroma in a patient with von Recklinghausen disease (NF-1).

METHODS

Case report. A physical examination and histopathology were performed. The immunohistochemical studies were performed using an avidin-biotin-peroxidase complex technique on formalin-fixed and paraffin-embedded tissue. Histologic sections from corneal tissue were incubated with primary antibodies against vimentin and S-100 protein. A complementary ultrastructural study of the same formalin-fixed and paraffin-embedded tissue was made.

RESULTS

The ophthalmologic examination revealed a yellowish-white elevated mass that involved the supratemporal cornea but not the limbus. Histologic study showed a tumor of the peripheral nerve sheath, a diffuse neurofibroma in the corneal stroma, and proliferation of spindle cells with markedly elongated nuclei. Cells comprising the tumor reacted with vimentin and S-100 protein, and the ultrastructural studies revealed myelinated nerve fibers confirming the diagnosis.

CONCLUSION

The development of a primary diffuse neurofibroma in the cornea of patients with von Recklinghausen disease is possible. The present case supports the statement that neurofibromas arising from the peripheral nerve sheath may involve any part of the body.

Localized neurofibroma of the orbit: a radiographic and histopathologic study

PURPOSE

To demonstrate the clinical, radiographic, intraoperative and histopathologic presentation of a localized neurofibroma of the orbit.

METHODS

Clinicopathologic case report.

RESULTS

A 25-year-old man was examined for inferior displacement of the right globe. Physical examination and neuro-imaging identified a localized solid tissue mass of the superior orbit. Histopathologic evaluation after complete surgical resection proved the lesion to be a localized neurofibroma.

CONCLUSIONS

The patient's history, clinical presentation, and imaging studies were strongly characteristic for this infrequently encountered orbital lesion. Several imaging features, including multilobulation, multiplicity, ring-configured contrast enhancement, and magnetic resonance imaging (MRI) signal intensity heterogeneity, when present in combination, may be reasonably diagnostic of this tumor.

Peripheral nerve tumors of the orbit

Neurofibromas and schwannomas are orbital neoplasms with similar clinical and radiologic features. Solitary or circumscribed neurofibromas and schwannomas demonstrate slow progressive growth with ocular displacement and are amenable to surgical resection. Plexiform and diffuse neurofibromas are diffusely infiltrative in the orbit and periocular region, they are difficult to resect, and they have a high rate of recurrence. Malignant peripheral nerve tumors are rare, but they have a very high rate of recurrence and a low 5-year survival rate because of extension through the superior orbital fissure to the midbrain region. This article describes the clinical and radiologic features of peripheral nerve sheath tumors.

Bilateral Localized Orbital Neurofibromas

BACKGROUND

The authors report on a 30-year-old man who presented with progressive bilateral exophthalmos over a 2-year period.

FINDINGS

Computed tomography showed large heterogeneous masses in the superior aspect of both orbits. Excisional biopsy via bilateral lateral orbitotomies showed the tumors to be well-circumscribed, relatively avascular, localized neurofibromas. The patient had several features suggestive of multiple endocrine neoplasia type IIB, including Marfanoid habitus, enlarged corneal nerves, thickened lips, and mucosal neuromas.

CONCLUSION

Localized neurofibromas are rare in the orbit and, unlike plexiform neurofibromas, are not typically associated with von Recklinghausen's neurofibromatosis. Bilaterality of such localized neurofibromas has not been previously reported. Recognition of ophthalmic lesions suggestive of multiple endocrine neoplasia IIB should prompt evaluation for systemic manifestations of this disorder.

Benign mixed tumors arising in the palpebral lobe of the lacrimal gland

The accurate clinical diagnosis of benign mixed tumors of the lacrimal gland is imperative for proper therapeutic management. Although benign mixed tumors of the orbital portion of the lacrimal gland have an established identity, those tumors arising in the palpebral lobe are unusual. Four patients with benign mixed tumors of the palpebral lobe are presented, emphasizing the confusion that exists in making the diagnosis. Palpebral lobe benign mixed tumors should be strongly considered in the differential diagnosis of upper outer eyelid masses. En bloc resection avoids the risk of tumor spillage, recurrence, and/or malignant transformation caused by preliminary biopsy or incomplete resection.

Extracranial and extraspinal nerve sheath tumors: computed tomographic evaluation

Thirty-five patients with 37 peripheral nerve sheath tumors (NST) (16 schwannomas, 11 neurofibromas, 5 plexiform and 1 diffuse neurofibroma, and 4 malignant NST) were studied respectively. The benign NST usually appeared on CT as well-defined oval, spherical or fusiform masses, centered at the expected anatomic location of a cranial, spinal, autonomic or peripheral nerve with characteristic displacement of adjacent muscles and blood vessels. None of the schwannomas appeared homogeneously hypodense on IV enhanced CT, whereas close to half of neurofibromas and plexiform neurofibromas were so. This fact, which had not been reported in the past, may be related to differences in inherent vascularity and blood-nerve barrier (fenestrated blood vessels) between schwannomas and neurofibromas and may be a useful distinguishing CT feature. The most reliable, though not infallible criterion of malignant NST was poor definition of their margins. Ninety-two per cent of NST (34 out of 37) were diagnosed or included in a limited differential pre-operatively.

Localized orbital neurofibromas

Of nine patients (five men and four women, 25 to 55 years old) with localized orbital neurofibromas, only one had other systemic findings consistent with neurofibromatosis. The neurofibromas originated from sensory nerves of the orbit, producing gradual proptosis with expansion of the orbital walls in most cases. Mild orbital discomfort occurred in some patients. Preoperative and postoperative anesthesia in the distribution of the involved sensory nerves was also encountered. Five patients had multiple tumors within the same orbit. Four patients had tumors or a pedicle of the tumor extending into the superior orbital fissure. Two patients were initially thought to have fibrotic pseudotumors. Surgical excision is the treatment of choice for these tumors.