You will be presented with the full text of a biomedical research paper. Please write an abstract for this paper. Your response should include the abstract and no additional text.

Paper text:
lichen myxedematosus ( lm ) is a primary mucinosis that is not accompanied by thyroid disease . in the updated classification of lm given by rongioletti et al .
[ 1 , 2 ] , the nodular type is one subset of lm that is characterized by multiple nodules on the limbs and trunk with mild or absent papular eruption .
herein , we report a case of nodular - type lm for which local injection of corticosteroids was effective .
an 18-year - old japanese woman noticed a progressive appearance of nodules on both forearms and on the left cubital fossa and left thigh one year before her initial consultation at our department for further evaluation in 2008 .
physical examination revealed elastic hard , slightly elevated , shiny and yellowish to skin - colored nodules of 6 to 10 mm in size on her extremities without confluence into plaque .
1 ) , three on the left forearm , four on the left cubital fossa , and two on the left thigh . the nodules were not itchy .
laboratory findings for liver function , free t3 , free t4 , thyroid - stimulating hormone , fasting blood sugar , and hba1c were all within normal limits .
xanthoma and dermatofibroma were suspected based on the clinical appearance , and one nodule on the right forearm was taken for skin biopsy .
histopathologically , collagen fibers were separated in the reticular to deep dermis without epidermal changes ( fig .
basophilic mucin deposits between collagen fibers with proliferation of fibroblasts and infiltration of lymphocytes and plasmacytes around vessels were seen in the dermis .
histochemically , the mucin was positive for alcian blue and negative after hyaluronidase digestion ( fig
treatment with betamethasone dipropionate ointment was ineffective , but one nodule was completely eliminated by local injection of 0.02 ml triamcinolone acetonide ( 8 mg / ml ) . since triamcinolone acetonide was subsequently recalled and was unavailable for a period , we tried local injections of 0.1 mg prednisolone sodium succinate three times for each nodule .
after triamcinolone acetonide reappeared in the japanese market , local injection of 0.02 to 0.05 ml triamcinolone acetonide was performed and another three injected nodules were completely eliminated .
lm ( papular mucinosis ) is a disorder characterized by lichenoid papules , nodules and/or plaques due to dermal mucin deposition , and a variable degree of fibrosis without thyroid dysfunction . in an updated classification [ 1 , 2 ]
, lm is divided into the following clinicopathologic subsets : ( 1 ) a generalized papular and sclerodermoid form ( scleromyxedema ) with monoclonal gammopathy and systemic manifestations that may be lethal .
histologically , the skin shows a microscopic triad of mucin deposition , fibroblast proliferation , and fibrosis ; ( 2 ) localized lm , which is a papular or nodular / plaque eruption without sclerotic features , monoclonal gammopathy , or systemic involvement ; here , the skin shows mucin deposition with variable fibroblast proliferation ; and ( 3 ) atypical forms , which have atypical features or features intermediate between scleromyxedema and localized lm .
localized lm is further subdivided into the following four subtypes : ( 1 ) discrete lm , which has firm , smooth , waxy or flesh - colored papules of 2 to 5 mm in size , numbering a few to hundreds on the limbs and trunk in a symmetric pattern .
the papules are isolated or form confluent nodules or plaque and rarely resolve spontaneously ; ( 2 ) acral persistent papular mucinosis , which is characterized by a few to multiple , ivory to flesh - colored papules of 2 to 5 mm in size on the back of the hands , wrists , and occasionally the distal aspect of the forearms .
papules persist or increase without spontaneous resolution and occur predominantly in females ; ( 3 ) cutaneous mucinosis of infancy , characterized by firm , opalescent papules located on the upper arms , especially the elbows , and the trunk without spontaneous resolution , and ( 4 ) nodular - type lm , characterized by multiple nodules on the limbs and trunk , with a mild or absent papular component .
our case was diagnosed as nodular - type lm based on the clinical and histological features .
the patient had 8 nodules of 6 to 10 mm in size on the legs and forearms without a symmetric pattern , whereas papules on the limbs and trunk more commonly occur in a symmetric pattern in discrete lm , and occur on the back of the hands and extensor surface of the distal forearms in acral persistent papular mucinosis .
histological findings , such as mucin deposition with variable fibroblast proliferation and the absence of monoclonal gammopathy and m protein , provided further reasons for the diagnosis of nodular - type lm . only three previous cases [ 4 , 5 ] characterized by nodular - type lm have been reported , including one from japan .
the mean onset age of the four reported patients with nodular - type lm , including our case , was 30.5 years ( range 1848 years ) , which suggests that this subtype appears at a younger age compared to discrete lm and acral persistent papular mucinosis .
moreover , three of the four cases were male ( table 1 ) . a standard treatment for localized lm is not described in the literature , but in our case nodules showed complete remission following local injection of triamcinolone acetonide , which suggests that this drug may be of some benefit for this condition .
an 18-year - old japanese woman noticed a progressive appearance of nodules on both forearms and on the left cubital fossa and left thigh one year before her initial consultation at our department . 
 physical examination showed elastic hard , slightly elevated , shiny and yellowish to skin - colored nodules of 6 to 10 mm in size on her extremities . from laboratory and histopathological findings 
 , nodular - type lichen myxedematosus was diagnosed and nodules showed complete remission following local injection of triamcinolone acetonide .