Characterization of lacrimal sac histology: an immunohistochemical study

Frozen Section Histoanatomy of the Peritarsal Eyelid

BACKGROUND

Mohs surgery of eyelid skin cancers requires detailed knowledge of anatomy for precise surgery and accurate evaluation of histology.

OBJECTIVE

To review the histology of the peritarsal eyelid using frozen sections as encountered intraoperatively by Mohs surgeons.

METHODS

The authors review the literature describing the anatomy and histology of the peritarsal eyelid from the lens of a Mohs surgeon. Histology from select Mohs cases is used to frame the discussion of the microanatomy of this region.

RESULTS

The peritarsal eyelids contain a unique mixture of skin, muscle, tarsus, glandular tissue, and conjunctiva. The histologic appearance of many of these structures differs from skin found outside of this anatomic region. Tumors of the eyelid and periocular region may mimic normal histologic structures found within the peritarsal eyelid.

CONCLUSION

The peritarsal eyelids have unique anatomy and associated histologic structures. Knowledge of the detailed histoanatomy is required for confident execution of Mohs surgery in this anatomic region.

Etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO)

Primary acquired nasolacrimal duct obstruction, or PANDO, is a common adult lacrimal drainage disorder. The current treatment modality of dacryocystorhinostomy to bypass the obstructed nasolacrimal duct has excellent outcomes. However, the understanding of the disease etiopathogenesis needs to be revisited. There are not many studies that specifically assessed any hypothesis or ones that convincingly put forth the presumed or confirmed interpretations regarding the PANDO pathogenesis or the mechanisms or pathways involved therein. Histopathological evidence points to recurrent inflammation of the nasolacrimal duct, subsequent fibrosis, and the resultant obstruction. The disease etiopathogenesis is considered multifactorial. Several implicated suspects include anatomical narrowing of the bony nasolacrimal duct, vascular factors, local hormonal imbalance, microbial influence, nasal abnormalities, autonomic dysregulation, surfactants, lysosomal dysfunction, gastroesophageal reflux, tear proteins, and deranged local host defenses. The present work reviewed the literature on the etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO) to gain insights into the present state of the understanding and the high-value translational implications of precisely decoding the disease etiology.

Liquid-based thin-prep cytology study of lacrimal drainage system in primary acquired nasolacrimal duct obstruction

PURPOSE

We investigated the cytologic findings of primary acquired nasolacrimal duct obstruction (PANDO) based on the thin-prep cytology method using sheath-guided dacryoendoscopy.

METHODS

A retrospective review was conducted of 66 cases from 50 patients who were diagnosed with PANDO. Slit-lamp examination, the lacrimal irrigation test, and dacryocystography were performed for the evaluation of PANDO. The dacryocystography (DCG) findings were classified into primary and secondary change. Each patient was treated with transcanalicular dacryoplasty using catheter sheath-guided dacryoendoscopy (RUIDO Fiberscope, Fiber Tech Co., Ltd., Tokyo, Japan) and obtained cytologic specimens. The liquid-based thin-prep cytology method was used for the analysis of histopathology.

RESULTS

The cellular detection rate was as follows: epithelial cells with 56 cases (84.8%), 33 cases (50.0%) with inflammatory cells, 1 case (1.5%) with mucin, and bacterial colonies with 2 cases (3.0%). In the dacryoendoscopic findings, all cases of a presence of pus were related to the detection of the columnar epithelium (p = 0.026), while there was no statical significance according to the presence of an epithelial cell. In the DCG findings, the PANDOs with the secondary change showed a higher detection rate than those with the primary change (p = 0.005), and columnar epithelial cells were observed (p = 0.011). The detection rate of inflammatory cells was 50.0% (33/66) and all inflammatory cells were lymphocytes but it was not correlated with clinical findings. One case of mucin (1.5%) and 2 cases of bacterial colonies (3.0%) were presented using liquid-based thin-prep cytology analysis. The overall success rate of transcanalicular dacryoplasty and silicone intubation was 86.4%.

CONCLUSION

Liquid based thin prep cytology can be used to analyze histopathological changes of lacrimal passage in PANDO without invasive biopsy. These cytologic findings of lacrimal passage provide a better understanding of the pathogenesis of lacrimal passage in patients with PANDO.

Lacrimal sac diverticulum: clinical presentation and endoscopic management

BACKGROUND

To describe the clinical presentation, surgical intervention and clinical outcomes of patients with a lacrimal sac diverticulum.

METHODS

Retrospective chart review of all patients who underwent endonasal endoscopic dacryocystorhinostomy (DCR) in a single medical center from January 2010 to October 2020. The diagnosis of a lacrimal sac diverticulum was based upon intraoperative findings.

RESULTS

In total, 406 patients underwent endonasal endoscopic DCR during the study period. Eight female patients (mean age 35 years) were diagnosed with a lacrimal diverticulum and underwent DCR by an endonasal endoscopic approach. The mean follow-up period was 11.5 months. All eight patients had cystic findings at the lacrimal fossa on imaging studies prior to surgery. Five patients had a history of dacryocystitis. The main presenting symptoms were epiphora and/or medial canthal swelling. The diverticulum was identified on the inferior wall in seven cases. A dacryolith in the lacrimal sac was identified intraoperatively in two patients. All patients showed full resolution of symptoms after surgery. There were no intraoperative or postoperative complications.

CONCLUSION

Lacrimal sac diverticulum is a rare entity with female predominance. It may be the underlying etiology of epiphora and/or dacryocystitis. The diagnosis is based upon identifying the presence of a diverticulum intraoperatively. Endoscopic DCR is an effective approach for integrating both the lacrimal sac and diverticulum cavities into a single space, leading to resolution of symptoms.

Adding myofibroblasts to the lacrimal pump

The lacrimal sac (LS) empties in the nasolacrimal duct to drain the tears in the inferior nasal meatus. Different studies indicated the role of the lacrimal pump in the lacrimal drainage. Although controversial, the lacrimal pump mechanism is an extrinsic one, either active, or passive. An intrinsic contractile potential of the LS was not documented previously. We thus aimed a retrospective immunohistochemical study to test the alpha-smooth muscle actin (α-SMA) and h-caldesmon expression in the LS wall. We used archived paraffin-embedded samples of LS from ten adult patients. The α-SMA + phenotype was detected in basal epithelial cells, in subepithelial ribbons of stromal cells, in vascular smooth muscle cells, as well as in pericytes. H-caldesmon was exclusively expressed in pericytes, vascular smooth muscle cells and myoepithelial cells of the subepithelial glands. The most striking feature we found in all samples was a consistent stromal network of α-SMA+/h-caldesmon- myofibroblasts. This finding supports an intrinsic scaffold useful for the lacrimal pump.

Etiopathogenesis of Primary Acquired Nasolacrimal Duct Obstruction: What We Know and What We Need to Know

PURPOSE

To provide a systematic review of the literature on the etiopathogenesis of primary acquired nasolacrimal duct obstruction (PANDO).

METHODS

The authors performed a PubMed search of all articles published in English with specific reference to etiopathogenesis of PANDO or associations of PANDO. Data captured include demographics, study techniques, hypothesis, presumed or confirmed interpretations with regards to pathogenesis, mechanisms, or pathways. Specific emphasis was laid on addressing the lacunae and potential directions for future research.

RESULTS

Numerous factors are believed to contribute to the etiopathogenesis of PANDO. The basic pathogenesis involves inflammation, vascular congestion, mucosal edema, fibrosis, obstruction, and stasis. Bony nasolacrimal duct diameter does not appear to play a significant role. There is no convincing data to substantiate nose as the site of disease origin and nasal factors appear to be comorbidities. Hormonal mechanisms are more evidence-based but can only partly explain the pathogenesis. Vascular theories are based on the behavior of perilacrimal cavernous bodies, their autonomic control, and additional structural changes in the helical patterns of connective tissue fiber arrangements. Repeated vascular malfunction leading to structural epithelial and subepithelial changes currently appears to be the most evidence-based and accepted theory. Tear proteomics holds a promise in decoding the etiopathogenesis of PANDO, at least in part.

CONCLUSIONS

The etiopathogenesis of PANDO appears to be multifactorial. Hormonal microenvironments, vascular factors, and tear proteomics are promising candidates for further work. There is a need for focused work by Clinician-Scientists and the answers can have far reaching clinical implications.

Biopsy of recurrent nasolacrimal duct obstruction using sheath-guided dacryoendoscopy

PURPOSE

The purpose of this article is to present a novel technique, as well the histopathological findings, of dacryoendoscopic guided nasolacrimal duct (NLD) biopsy for recurrent nasolacrimal duct obstruction (NLDO).

METHODS

This study involved subjects with recurrent NLDO. Direct endoscopic probing or sheath-guided endoscopic probing was used for the initial intubation in all treated eyes, and the stent had been removed at between 2 and 11 months (mean 3.5 months) post-intubation with dacryoendoscopic confirmation of patency and mucosal regeneration. Biopsy specimens were obtained by scraping the recurrent lesion by sheath advancement. Histopathological examination and immunohistochemical (IHC) staining were performed.

RESULTS

In five patients (two males and three females, mean age: 71.2 ± 5.6 years [range: 61-78 years]) with recurrent NLDO, biopsy specimens were obtained from six ducts of six eyes, and stratified epithelium and a mixed inflammatory cell infiltrates were identified. IHC staining was positive for cytokeratin (CK)4 and CK13, and negative for paired box protein Pax-6.

CONCLUSIONS

This novel technique enabled a minimally invasive biopsy of the NLD to be obtained, and IHC staining indicated the presence of mucus epithelium, thus suggesting squamous metaplasia of the usual respiratory epithelium which likely occurs secondary to chronic inflammation.

Pathologic features and expression of heat shock protein 47 in the nasal mucosa and lacrimal sac: does it influence the surgical outcome of endoscopic endonasal dacryocystorhinostomy?

PURPOSE

To correlate the pathologic features and heat shock protein 47 (HSP47) expression in the nasal mucosa and lacrimal sac with the surgical outcomes of endoscopic endonasal dacryocystorhinostomy (EDCR).

METHODS

Specimens of the nasal mucosa and lacrimal sac over the rhinostomy site were collected during the operation. Haematoxylin-eosin and immunohistochemical staining were performed to determine the pathologic features (inflammation, fibrosis, squamous metaplasia) and the expression of HSP47 in the epithelium and sub-epithelial glands of the nasal mucosa and lacrimal sac. The success or failure of EDCR was determined 6 months after surgery.

RESULTS

A total of 30 patients (30 eyes) were included in this study. Inflammation and squamous metaplasia of the nasal mucosa were not associated with the surgical outcome of EDCR (p = 0.485 and 0.069, respectively), but there was an association with fibrosis of the nasal mucosa (p = 0.003). In addition, HSP47 in the nasal mucosa was associated with the surgical outcomes (p = 0.005). Inflammation of the lacrimal sac was not associated with the surgical outcome of EDCR (p = 0.509), but fibrosis and squamous metaplasia of the lacrimal sac were (p = 0.005 and 0.008, respectively). Additionally, HSP47 in the lacrimal sac was associated with surgical outcomes (p < 0.001).

CONCLUSION

Fibrosis and squamous metaplasia of the nasal mucosa and lacrimal sac lowered the success rate of EDCR. HSP47 also lowered the surgical success rate. Fibrosis was correlated with the expression of HSP47.