Conjunctival Stromal Tumor: Expansion of Findings in a Newly Described Entity

Bindehautdegenerationen und -neoplasien

Erhabenheiten der Bindehaut entstehen durch Gewebevermehrung, die entweder degenerativ oder neoplastisch, aber auch entzündlich sein können. In diesem Artikel werden degenerative (Pterygium und Pinguecula) sowie benigne und maligne neoplastische Bindehautveränderungen (epitheliale, melanozytäre und vaskuläre Tumoren, Choristome sowie Metastasen) bezüglich der Pathogenese, Symptome, Diagnostik und aktuellem Stand der Behandlung dargestellt.

[Conjunctival Degeneration and Neoplasia]

Conjunctival tumors result from gain of tissue, which can be either degenerative or neoplastic, but also inflammatory. In this article, degenerative (pterygium and pinguecula) as well as benign and malignant neoplastic conjunctival changes (epithelial, melanocytic and vascular tumors, choristomas as well as metastases) are discussed with regard to pathogenesis, symptoms, diagnostics and current status of treatment.

Epibulbar Proliferative Fasciitis, a Variant of Nodular Fasciitis: A Differential Diagnosis of Conditions With Focal or Diffuse Myxoid Stromas

PURPOSE

To describe the clinical and pathologic features of a case of epibulbar proliferative fasciitis and to compare it with other focal or diffuse myxoid lesions.

METHODS

A clinical, histopathologic, and immunohistochemical analysis was performed. The clinical history, photographic documentation, history, and referred slides were reanalyzed. Additional immunohistochemical stains were performed at our institution.

RESULTS

A 68-year-old woman developed over a week a brightly vascularized and focally hemorrhagic placoid lesion on the temporal side of the OS. She had had earlier augmentation breast surgery that had been mistakenly initially reported to us to be for breast carcinoma. Hematoxylin- and eosin-stained reactions revealed microscopically a spindle cell lesion with an intact nonkeratinizing epithelium and a background myxoid stroma with prominent capillaries and a light dispersion of small T-cell lymphocytes. Most striking among the spindle cells were some widely separated large atypical cells. The atypical cells were cytokeratin positive, but an expansive panel of immunohistochemical stains for breast carcinoma was negative. The lesion was diagnosed as proliferative fasciitis and has not recurred after 1-year follow up.

CONCLUSION

A rapidly evolving conjunctival lesion is unlikely to be a primary or metastatic carcinoma. In the current case, the large ganglioform or rhabdomyoblast-like cells displayed diffuse cytokeratin positivity, still consistent with a mesenchymal or connective tissue cell lineage. Cytokeratin expression has been a finding previously reported in connective tissue tumors and in lymphoma cells. While the current lesion clinically resembles a conventional nodular fasciitis, the presence of the large atypical cells can lead to the misdiagnosis of a sarcoma, which typically displays a much higher Ki-67 proliferation index in comparison with nodular/proliferative fasciitis.

Conjunctival myxoma: A systematic review of a rare tumor

Conjunctival myxoma is an uncommon benign tumor that may develop as a localized disease or as part of the Carney complex, in which case it can cause significant morbidity and mortality. Conjunctival myxomas can mimic other pure or mixed tumors and are often overlooked in clinical practice. Histopathological studies are essential for diagnosis; however, controversy regarding their pathological and immunohistochemical features makes the diagnostic process more difficult. Because of the importance of correctly classifying these conjunctival tumors, as well as recognizing when a systematic screening is required owing to the possible association with life-threatening diseases, we comprehensively evaluate the literature on this rare entity based on a systematic approach.

Conjunctival Stromal Tumor: Report of 2 New Cases and Review of the Literature

Conjunctival stromal tumor (COST) is an emerging entity with only a limited number of cases reported in the literature. In this report, we describe 2 additional cases, review the accumulative clinical and histopathological features and expand on the immunophenotypic property of this entity. COST appears to have a sporadic presentation, affecting both sexes and patients of variable ethnicity and age group and predominantly occurring on the bulbar conjunctiva as a slow-growing asymptomatic or slightly tender mass-like lesion. Histopathologically, COST is characterized by singly dispersed spindle to round cells, often with some degree of degenerative nuclear atypia, within a myxomatous to collagenous stroma. Lesional cells are characteristically positive for CD34 and vimentin, negative for S100, SOX10 and STAT6 and show a normal pattern of staining with RB1 by immunohistochemistry. The reported cases to date have shown an indolent biological behavior, reliably treated by a complete surgical excision.

Conjunctival stromal tumour (COST): anterior-segment OCT findings

Conjunctival stromal tumour (COST) is a recently described rare conjunctival tumour of mesenchymal origin with only four publications describing a handful of cases thus far. In this report, we describe the anterior-segment optical coherence tomography (AS-OCT) characteristics in a case of COST for the first time, in addition to the clinical and histopathological characteristics. The AS-OCT showed an elevated, dome-shaped hyporeflective homogenous lesion in the conjunctival stroma lined by hyperreflective outer layer with mild posterior shadowing, consistent with histological description of a paucicellular tumour with large myxoid collagenous material inside. Immunohistochemistry showed positive CD34 and vimentin but negative S100 and smooth muscle actin, thereby differentiating it from conjunctival myxoma.

Ocular Surface Fibroma: Clinical, Histopathological, and Immunohistochemical Features of 10 Cases

Aim

To describe the clinical, histological, and immunohistochemical (IHC) features of a series of 10 cases of ocular surface fibroma (OSF) and correlate the findings with other similar histological entities.

Method

The patient demographics and features of the lesions were analysed from the clinical notes. All cases in the series had routine diagnostic excisional biopsies with standard histopathological and IHC evaluation. Each case was analysed by histology and immunohistochemistry with antibodies to: CD34, Factor XIIIa, desmin, smooth muscle actin, S100, Melan-A, β-catenin, neurofilament, and Ki67.

Results

OSF occurred on the bulbar, tarsal, or forniceal conjunctiva, and typically presented as a white, pink, or yellow sheet-like or nodular lesion. The most common symptom was irritation or a foreign-body sensation. Lesions ranged in size from 4 to 13 mm. Only 1/10 cases showed a recurrence after an incomplete excision. Histologically, OSF comprised bland spindle cells in a collagen stroma. The spindle cells were CD34-positive (in 10/10 cases) and a smaller subset was positive for Factor XIIIa (6/10 cases). Normal resident spindle cells in the conjunctival stroma, Tenon's capsule, and tarsal plate were positive for CD34 and Factor XIIIa, implicating these cells in the origin of OSF.

Conclusion

OSF is a benign lesion of resident CD34- and Factor XIIIa-positive spindle cells in the conjunctiva and Tenon's capsule. We have called to attention another lesion to be included by clinicians in the differential diagnosis of benign ocular surface lesions composed of CD34- and Factor XIIIa-positive spindle cells.

Conjunctival Myxoid Lesions: Clinical-Pathologic Multiparametric Analysis, Including Molecular Genetics (An American Ophthalmological Society Thesis)

PURPOSE

To evaluate the clinical and pathologic characteristics of conjunctival myxoid lesions, with specific focus on PRKAR1A studies, in order to distinguish neoplastic conjunctival myxoma from other myxoid conjunctival lesions.

METHODS

A retrospective, interventional, multicenter study of all patients with conjunctival myxoma, conjunctival stromal tumor, or reactive fibromyxoid proliferation diagnosed during 1988-2018. Patient and family medical histories and clinical and pathologic characteristics of excised lesions were assessed.

RESULTS

There were 28 patients with conjunctival myxoid lesions diagnosed as myxoma (16/28), conjunctival stromal tumor (10/28), or reactive fibromyxoid proliferation (2/28). The patients with abundant myxoid matrix lesions (14/28, 50%) were younger (mean 49 [range 23-68] years) than those with scant-to-moderate myxoid matrix lesions (14/28, mean 61 [range 18-82] years; P = .04). Abundant myxoid matrix lesions more likely contained predominantly stellate cells (6/14 [43%] vs 0/14 [0%]; P = .05) and fibrillar collagen (13/14 [93%] vs 2/14 [14%]; P < .0001), conforming to the standard morphologic definition of myxoma. Absence of PRKAR1A protein expression was found in 2 lesions with morphologic features of myxoma (2/14, 14%), 1 of which demonstrated a pathogenic mutation in the PRKAR1A gene. There was no difference between the lesions with respect to other clinical and pathologic parameters.

CONCLUSIONS

PRKAR1A plays a role in the development of a subset of conjunctival myxomas, particularly in tumors fulfilling stringent morphologic criteria for myxoma. With the exception of PRKAR1A studies, current immunohistochemical panels cannot reliably distinguish between neoplastic conjunctival myxomas and other myxoid lesions, underscoring the importance of morphology in establishing accurate diagnosis.

Conjunctival myxoid stromal tumour: a distinctive clinicopathological and immunohistochemical study

BACKGROUND/AIMS

To describe the clinicopathological and immunohistochemical characteristics of 10 patients representing a new entity of benign conjunctival myxoid stromal tumours.

METHODS

Retrospective review of clinical findings, histopathological and immunohistochemical studies identified 10 cases of low-grade conjunctival myxoid stromal tumours. Specimens were routinely processed and stained with H&E. Immunohistochemical stains for CD34, CD68, vimentin, S100, smooth muscle actin (SMA), myosin, desmin, actin, Bcl-2 and Ki-67 were performed. Specific stains for Alcian-blue periodic acid-Schiff (AB-PAS) and aldehyde fuchsin stains were also performed.

RESULTS

Ten patients with an average age of 45.6±11.1 years had a tender white or faint yellow to red mass on the bulbar conjunctiva. All the lesions were completely removed, and none of the patients relapsed. Histologically, all neoplasms consisted of spindle-shaped cells that showed signs of pseudonuclear inclusions, multinuclear cells and had no atypia. The stroma consisted of a large amount of mucus and was infiltrated with delicate to ropey collagens, a few mast cells and new vessels. Immunohistochemical stains were positive for CD34, vimentin and Bcl-2; partial positive for CD68; very low for Ki-67; and negative for S100, SMA, myosin, desmin and actin. AB-PAS suggested that the stroma was mucinous.

CONCLUSIONS

These rare benign mesenchymal conjunctival tumours are mostly unilateral and occur in the bulbar conjunctiva. Complete resection is the radical treatment. These lesions are characterised by multiple spindle cells, a large amount of mucus, and sharing similar basic histopathological features with conjunctival myxoma and conjunctival stromal tumour. We suggest naming these lesions 'conjunctival myxoid stromal tumours'.