Physical examination revealed that the number of nodules was approximately ten, which were located mainly in the center of both palms and soles, and these ranged in size from approximately 0.5 cm to 1.5 cm in diameter (Fig. 1). As the nodules of the soles were deeply located, they were not visible, but palpable. No limitation of hand or finger motion was observed. No joint swelling or other specific skin lesions were found.

Laboratory tests, including blood cell count and blood chemistry, were all within normal ranges. However, a rheumatologic evaluation yielded a positive antinuclear antibody (homogeneous pattern) and positive serum rheumatoid factor with a titer of 5+ (1:16) (positive range 1+~5+). Hand X-ray showed no remarkable findings, except for mild osteoarthritic changes in distal interphalangeal joints. For histological diagnosis, a 4 mm punch biopsy was performed from one of the lesions on the left palm. Histopathological findings showed relatively well-demarcated cellular proliferation, including slit-like vascular channels and haphazardly-arranged, spindle-shaped fibroblasts located among the dense collagenous matrix (Fig. 2).

This case may be very unique in that FTS occurred multifocally and concurrently on the palms and soles. The patient complained of rheumatic symptoms, including morning stiffness, and his blood test showed a high titer of rheumatoid factor and a positive result for anti-nuclear antibody. However, X-ray findings and other physical examination did not fit into the Revised Criteria for Rheumatic Arthritis by the American College⁸. He has shown only mild osteoarthritic changes in distal interphalangeal joints of both hands, but not in proximal interphalangeal or metacarpophalangeal joints, which were the favorite involved site in rheumatoid arthritis. Joint damage in rheumatoid arthritis usually occurs within the first 2 years⁹. Although he presented with 5 years of long standing history, the patient did not show any definite rheumatoid arthritic pathophysiological findings in X-rays, except for serum positivity and morning stiffness.

The pathogenesis of FTS has not been clearly established with regard to whether the origin is a neoplasm or reactive fibrosing process. Dal Cin et al¹⁰. reported that the presence of clonal chromosomal abnormality characterized by a t(2:11)(q31-32:q12) in ten out of 20 karyotyped cells suggested that this proliferation is not a reactive fibrosing process, but a neoplasm. Others have found that the right hand was more frequently affected than the left, and most cases occurred in the palm of hand and in the plantar region of the foot¹¹. This finding suggests that the origin of FTS may be a reactive process by trauma, stimulation, or inflammation. This case also favored the reactive pathogenesis in formation of FTS. Skin lesions developed on palms and soles and are consistently affected by prolonged pressure and motion. Seropositivity for rheumatoid factor may indicate prolonged inflammation, which could be associated with multiplicity in this patient. His symptoms of morning stiffness and numbness showed moderate improvement with administration of oral anti-inflammatory agents. Since we placed him on oral anti-inflammatory agents, the number and size of FTSs have been maintained. From these findings, sustained inflammation and stimulation may play an important role in FTS and its multiplicity.

The majority of patients with FTS are between the ages of 20 and 40 years and the male: female ratio has been described as 1.5~3:1^7,11. Most patients do not complain of any symptoms. However, 31% of cases present with tenderness and mild pain due to compression of nerves underlying FTS¹¹. Numbness and morning stiffness were observed in this case also. Although his symptoms were controlled by oral anti-inflammatory agents, the possibility of compression of nerve on palms and soles cannot be excluded. Therefore, even though it is practically difficult to excise out all FTSs, removal of the tumor is necessary, which provokes pain. Surgery for local excision should be performed carefully, because the recurrence rate is 24% and all of the cases are in the hands and finger⁷.

Differential diagnosis should be made with an epidermal cyst, mucinous cyst, neuroma, leiomyoma, nodular fasciitis, and giant cell tumor of the tendon sheath (GCTTS)¹². In particular, clinical features of GCTTS are similar to those of FTS. However, FTS is distinguished from GCTTS by histopathologic features, which include the fact that GCTTS are less hyalinized and more cellular, and with histiocytes and monocytes as well as multinucleated giant cells, foam cells, and hemosiderin-laden macrophages^10,12. Regarding multiple nodules on the palmar area, Dupuytren's contracture should be considered as a differential diagnosis. It is the best known multiple palmar fibromatosis¹³. Clinical manifestation usually showed flexural contracture of the hand, particularly the ring and little finger area. This patient did not show any limitation of finer or hand movement; therefore, diagnosis of Dupuytren's contracture was easily ruled out in the clinical setting.