G Caponetti1; C Otis1; I Mert2; S Marconi1; V Schuster3; M Ziegler3; K Tefs3; J Hecht4; M Tug2 and L Pantanowitz1 1Baystate Medical Center/Tufts University, Springfield, MA; 2Zekai Tahir Burak Hospital, Ankara, Turkey;

3University of Leipzig, Leipzig, Germany and 4Beth Israel Deaconess Medical Center, Boston, MA.

ABSTRACT

Background: Ligneous inflammation (LI) is characterized by pseudomembranes and

inflammation. A possible autoimmune etiology similar to lichen sclerosus is proposed. There

have been no series of LI involving the female genital tract (FGT). We aimed to characterize

the morphology, genotype and immunophenotype of LI of the FGT.

Design: Tissue from 4 patients with LI (12 specimens), 10 of chronic cervicitis (CC), and 10 of

vulvar lichen sclerosus (LS) were studied. Sections were stained with H&E, PAS, PTAH,

Congo Red, CD3, CD4, CD8 and CD20. The distribution and proportion (graded 0-4) of T&B

cells was recorded. DNA from LI patients was studied for mutations in the plasminogen gene

(PLG) by PCR and direct sequencing.

Results: LI patients were of mean age 41 years, 2 with low plasminogen antigen and

functional activity (12% & 18% of normal). LI on biopsy showed abundant stromal deposits of

eosinophilic (Fig. 1), PAS+, PTAH+, Congo Red negative fibrin associated with chronic

inflammation. Table 1 shows the inflammatory infiltrate of LI resembles CC more than LS. In

LI cases with low plasminogen, there was a homozygous mutation in one patient and a

heterozygous mutation in another. No mutations were found in the other 2 women with LI.

Multiple PLG polymorphisms were detected in all four LI patients.

Conclusion: LI of the FGT is related to plasminogen deficiency secondary to PLG genetic

defects. Mutations in unidentified regulatory sequences of the PLG may explain the lack of

demonstrable genetic mutations in some cases. Failure of plasminogen to remove fibrin results

in tissue deposition. Given this molecular mechanism, and evidence that the inflammatory

infiltrate resembles a reactive process, a role for autoimmunity in LI appears unlikely.

The authors have no potential conflicts of interest to disclose.

BACKGROUND

Ligneous inflammation (LI) of the female genital tract is an uncommon but

distinctive condition, characterized by ligneous (“woody”) pseudomembranes

with subepithelial fibrin deposition and associated inflammation1.

The condition can be associated with infertility, and can involve extragenital

sites, most commonly the eyes (i.e. ligneous conjunctivitis), middle ear and oral

mucosa.

LI has been recently shown to be due to mutation(s) of the plasminogen gene

(PLG) and subsequent plasminogen deficiency, with failure to remove fibrin

upon deposition in injured mucosal tissue2.

A possible autoimmune etiology has been suggested3,4.

OBJECTIVE

The aim of this study is to characterize the morphological and genotypic

profile of LI of the female genital tract, and to define the immunophenotype

and nature of the associated inflammatory infiltrate through a comparative

case control study.

Ligneous Inflammation of the Female Genital Tract: Morphologic, Immunophenotypic, and Molecular Characterization

Medizinische Fakultät

RESULTS

The patients with LI (age range 20-82 year-old) presented with some of the

following complaints: primary infertility, dysmenorrhea, dyspareunia,

poscoital bleeding, pelvic pain, post-menopausal vaginal bleeding, vaginal

discharge, conjunctivitis and gingivitis.

Decreased plasminogen activity and antigen (12% 18% of normal) was

detected in two patients with LI.

Other laboratory values, including standard coagulation tests were within

normal values in all four LI cases.

H&E stains of the LI cases (n=12) revealed stromal deposits of amorphous

acellular eosinophilic material, consistent with fibrinous deposits, with diffuse

moderate chronic subepithelial and intraepithelial inflammatory infiltrates.

(Fig.1)

The cases of CC showed subepithelial and intraepithelial inflammatory

infiltrates, congestive vessels and mild edema in the connective tissue, along

with variable reactive epithelial changes. (Fig.1)

LS lesions were characterized by homogenous, acellular zones of subepithelial

sclerosis and band-like chronic inflammatory infiltrates. (Fig.1)

The proportion of CD3 and CD20 lymphocytes and their location was similar

in the LI and CC cases, and different from that of the LS cases. (Table 1)

Molecular genetic analysis of the PLG in the two LI patients with low

plasminogen yielded a type-1 homozygous K19E mutation in one patient and a

type-1 heterozygous K19E mutation in the other.

No mutations were identified in the PLG of the two patients with unknown

plasminogen levels.

Several PLG heterozygous and homozygous polymorphisms were detected in

all four patients.

CONCLUSION

LI of the FGT is related to plasminogen deficiency secondary to PLG genetic

defects.

Failure of plasminogen to remove fibrin results in tissue deposition.

Mutations in unidentified regulatory sequences of the PLG may explain the

lack of demonstrable genetic mutations in some cases.

Given this molecular mechanism, and evidence that the inflammatory

infiltrate resembles a reactive process, a role for autoimmunity in LI appears

unlikely.

REFERENCES

1. Karaer A, et al. Ligneous inflammation involving the female genital tract. J Obstet Gynaecol Res.

2007;33(4):581-4.

2. Tefs K, et al. Molecular and clinical spectrum of type I plasminogen deficiency: A series of 50

patients. Blood. 2006;108(9):3021-6.

3. Deen S, et al. Ligneous cervicitis; is it the emperor's new clothes? Case report and different analysis

of aetiology. Histopathology. 2006;49(2):198-9.

4. Scurry J, et al. Ligneous (pseudomembranous) inflammation of the female genital tract. A report of

two cases. J Reprod Med. 1993;38(5):407-12.

DESIGN

Tissue from 4 patients with LI (12 specimens), 10 of chronic cervicitis (CC),

and 10 of vulvar lichen sclerosus (LS) were studied.

Sections were stained with H&E, PAS, PTAH, Congo Red, CD3, CD4, CD8

and CD20.

The distribution and proportion (graded 0-4) of T and B lymphocytes was

recorded. (0=None, 1=Rare, 2=Few, 3=Several, 4=Many)

DNA from LI patients was studied for mutations in the plasminogen gene

(PLG) by PCR and direct sequencing.

Fig.1: Comparison of the histological appearance on H&E and the immunophenotypes of

Ligneous Inflammation (LI), Lichen Sclerosus (LS) and Chronic Cervicitis (CC).

LI

LS

CC

H&E CD3 CD20