Role of cytopathology in the diagnosis of ocular malignancies

Cytologic analysis of vitreous fluids: A retrospective review of our 24 years of experience

BACKGROUND

Cytologic analysis of vitreous fluid is an important component in diagnosis of vitreitis. No standard reporting guidelines exist for these specimens. This study chronicles our 24 years experience and proposes a tentative diagnostic model.

METHODS

Retrospective cytology reports review and database study. Clinical indications, cytologic patterns, ancillary studies performed, and diagnoses were recorded.

RESULTS

176 samples from 160 patients were included and main cytologic patterns are reflected in Table 1. Most fluids were negative for malignancy (88%) and patterns IIB (53%) and IIA (19%) were dominant. The non-diagnostic rate was 7%; atypical and suspicious categories represented <0.5% of fluids tested and only 2% were positive for malignancy (3 intraocular lymphoma and one melanoma). Clinical indications for fluid examination were infection/inflammation (59%), to rule out lymphoma (11%), amyloidosis (3%), melanoma (2%), or to investigate intraocular hemorrhage. Fungal elements were demonstrated in 7 cases. No viral inclusions were appreciated; however, one case was positive for HSV 2 by IHC and 2 were negative by PCR. One case had Gram + cocci. Flow cytometry studies were suboptimal in 6 fluids, negative for an aberrant lymphocyte population in 11, and positive for high grade lymphoma in 3 cases. Atypical, suspicious and positive for melanoma were reported in 3 samples. Amyloid was identified in 1 aspirate.

CONCLUSIONS

Cytologic analysis of vitreous fluid is a useful tool. Modern techniques like flow cytometry and PCR testing further expand the diagnostic possibilities. Standardization of diagnostic terminology will aid clinicians caring for patients suffering from ocular disease.

TWENTY-FIVE-GAUGE CANNULA-ASSISTED FINE-NEEDLE ASPIRATION BIOPSY OF CHOROIDAL MELANOMA: Cytopathological Analysis

PURPOSE

To report cytopathological observations on the cells retrieved from the 25-G cannula used during prognostic transvitreal fine-needle aspiration biopsy of choroidal melanoma.

METHODS

Transvitreal fine-needle aspiration biopsy of choroidal melanoma was performed through a 25-G valved cannula. Twenty samples from 20 consecutive patients were obtained. Most tumors were treated with plaque radiation therapy (16/20, 80%) following standard clinical guidelines. Four enucleated globes (4/20, 20%) were subjected to a similar transvitreal biopsy before enucleation.

RESULTS

Cytopathological analysis of the cells retrieved from the cannula revealed the absence of any cells in 4 of 20 samples (20%). In the remaining 16 samples, definite melanoma cells and atypical cells (probable melanoma cells) were observed in 2 samples each (total 4, 25%). Histiocytes (4/16, 25%) and lymphocytes (1/16, 6%) were also observed. Thirteen samples (13/16, 81%) contained conjunctival epithelial epithelium. Prognostication could be performed on all fine-needle aspiration biopsy samples (20, 100%).

CONCLUSION

Use of a 25-G valved cannula offers potential advantages by isolating the needle tract and by allowing retrieval of the contaminating cells without affecting the prognostic yield of the fine-needle aspiration biopsy sample.

Retinal pigment epithelium adenoma in vitreous fluid cytology

Ocular cytology specimens are relatively uncommon, adding to the difficulty of their evaluation by cytopathologists. While melanomas account for a majority of primary intraocular pigmented lesions, other diagnostic considerations must be included in the differential. This brief report highlights a case of a pigmented ocular lesion in a 24-year-old man and key morphologic, immunohistochemical, and clinical differences between melanoma, melanocytoma, choroidal nevus, and retinal pigment epithelium (RPE) adenoma.

Cytopathology of Vitreous Humor Samples in Routine Practice

OBJECTIVE

To describe findings in vitreous fluid samples in routine cytology practice.

STUDY DESIGN

The pathology archives from 1988 to 2008 at our institution were searched for vitreous samples. The slides were reviewed and clinical and follow-up information was obtained.

RESULTS

One hundred and eighty-two vitreous fluid samples from 166 patients were analyzed. Most of the samples had been collected for vitreous hemorrhage (75 cases). The second reason for vitreous sample cytological evaluation was an intraocular inflammatory process (55 cases). A specific cause of inflammation was found by combining clinical, microbiological and cytopathological findings in 19 cases, i.e. infection in 7, sarcoidosis in 3, retinal necrosis in 3, lens-induced endophthalmitis in 2, uveitis associated with systemic disease in 2, retrobulbar neuritis in 1 and sympathetic ophthalmia in 1. Among the 19 samples from 16 patients collected to rule out malignancy, 8 had a confirmed intraocular malignancy. Malignant cells were observed in 5 cases (3 lymphomas, 1 melanoma and 1 carcinoma). Undiagnosed malignancies included 2 lymphomas and 1 choroidal melanoma. Other samples were collected during surgery for retinal detachment and cataracts.

CONCLUSIONS

In routine practice, cytology of the vitreous fluid is performed in many and varied situations that are most often nonneoplastic. In nonneoplastic cases, cytology is a useful adjunct to vitrectomy, in spite of its limitations.

Fine needle aspiration biopsy of ophthalmic tumors

A majority of intraocular tumors can be diagnosed based on clinical examination and ocular imaging studies, which obviate the need for diagnostic ophthalmic fine needle aspiration biopsy (FNAB). Overall, diagnostic accuracy of ophthalmic FNAB is high but limited cellularity can compromise the diagnostic potential of ophthalmic aspirate samples. The role of ophthalmic FNAB is limited in retinal tumors. Orbital FNAB should be considered in the evaluation of lacrimal gland tumors, orbital metastasis, and lymphoproliferative lesions. Negative cytologic diagnosis of malignancy should not be considered unequivocal proof that an intraocular malignancy does not exist. With improved understanding of genetic prognostic factors of uveal melanoma, ophthalmic FNAB is gaining popularity for prognostic purposes in combination with eye conserving treatment of the primary tumor. In special clinical indications, ancillary studies such as immunohistochemistry and FISH can be performed on ophthalmic FNAB samples. Assistance of an experienced cytopathologist cannot be overemphasized.

Rapid cytologic diagnosis of choroidal malignant melanoma by vitreous smear

The eye is an uncommon subject of cytopathological examination. However, cytopathologic examination may be required for definitive diagnosis in some cases, as malignant tumors of the eye may sometimes be difficult to distinguish clinically from benign disorders. We report a case of malignant melanoma (MM) of the choroid, in which vitrectomy was performed for the initial clinical diagnosis of vitreous hemorrhage. As the dense vitreous hemorrhage was gradually cleared during the vitrectomy, a choroidal mass was discovered and the vitreous fluid was procured for rapid cytologic diagnosis. We used a modified Shorr's stain that can be completed within several minutes. With this method, highly atypical, pleomorphic cancer cells, occasionally associated with melanin pigment granules, were demonstrated. These cytologic findings indicated a diagnosis of MM arising from the choroid. Histologic examination of the enucleated eye confirmed MM of epithelioid type. The advantage and indication of the rapid cytologic diagnosis is discussed.