Juvenile hyaline fibromatosis (JHF) is a rare condition of childhood characterized by deposition of an amorphous substance of unclear nature in the dermis and subcutaneous tissues. The clinical picture includes painful skin lesions, leading to impairment of movements and severe disabilities. The allelic disease, infantile systemic hyalinosis (ISH), clinically overlaps with JHF but shows a worse picture with visceral involvement. Recently, germline mutations in the capillary morphogenesis gene-2 (CMG2) were found to be responsible for both diseases. Here, we present a case with classical clinicopathologic findings of JHF and features of ISH, and we describe a novel mutation in CMG2.

Three siblings with juvenile hyaline fibromatosis.J Oral Pathol Med. 2007 Feb;36(2):123-5.

Juvenile hyaline fibromatosis (JHF) is an extremely rare hereditary genetic disease of autosomal recessive transmission that is characterized by large cutaneous tumors commonly involving the scalp, papulonodular skin lesions, flexural joint contractures, gingival hyperplasia, and osteolytic bone lesions. JHF is usually diagnosed in young infants and in children younger than 5 years, and the lesions characteristic of this disorder consist of fibrous tissue and homogenous amorphous eosinophilic hyaline material. We report the case of a 9-year-old girl with severe gingival hyperplasia, nasal enlargement, mild osteoporosis, and multiple papulonodular skin lesions. Her two brothers (7 and 13 years of age, respectively) were also diagnosed as having JHF. In the patient described in this report, the maintenance of oral hygiene after gingivectomy enabled the continued resolution of gingival hyperplasia, although skin lesions recurred and nasal overgrowth persisted.

Juvenile non-hyaline fibromatosis: juvenile hyaline fibromatosis without prominent hyaline changes. J Cutan Pathol. 2005 Mar;32(3):235-9.

Juvenile hyaline fibromatosis (JHF) is a rare autosomal recessive disease of the connective tissue. It is characterized by papulonodular skin lesions, soft tissue masses, gingival hypertrophy, osteolytic bone lesions and flexion contractures of the large joints. Here, we report a 14-year-old girl with characteristic clinical features of JHF with early fatal outcome. Dermatopathologic examination of the early lesions however constantly lacked the so-called hyalin changes in multiple skin biopsies. According to our experience; dermatopathological features of this entity is not often and always consists of classical hyalinisation. Only larger lesions with long duration should expected to be exhibiting those features. Therefore we suggest that; JHF may often present itself as Juvenile Non-Hyaline Fibromatosis: JHF without prominent hyaline changes. And thus this fact should not change the actual diagnosis and prognostic implications.