Pachydermodactyly: A Case Report Including Histopathology

Pachydermodactyly: Soft Tissue Enlargement of the Fingers in a Teenager

Pachydermodactyly (PDD) is an uncommon and benign digital fibromatosis of unknown etiology. It is characterized by a fusiform swelling of the medial and lateral sides of the fingers, with unspecific histopathological features of an increased number of fibroblasts, collagen, and mucin deposit in the dermis. Due to its rarity, PDD could be misdiagnosed as rheumatic arthropathies, which could lead to unnecessary immunosuppressant treatments. Here, we report the case of a 16-year-old boy who presented progressive and asymptomatic soft tissue enlargement of multiple fingers in both hands. The histopathological study and X-ray findings correlated with PDD diagnosis. Intralesional corticoid treatment was indicated with a mild improvement.

Unilateral pachydermodactyly misdiagnosed as juvenile idiopathic arthritis: A case report

RATIONALE

Pachydermodactyly is a rare, benign disease that can manifest in healthy adolescent boys as painless, spindle-shaped, soft-tissue swelling of the proximal interphalangeal joints in the hand. It is usually bilateral, with symmetrical joint enlargement. There are relatively few documented cases of pachydermodactyly worldwide, signifying either a low incidence or lack of recognition by physicians; therefore, its diagnosis is challenging.

PATIENT CONCERNS

A 16-year-old boy with a 3-year history of painless unilateral swelling of the proximal interphalangeal joints of his left hand was misdiagnosed with juvenile idiopathic arthritis and was treated with oral methotrexate for 1 year. He had a history of frequent finger cracking.

DIAGNOSIS

He had normal levels of inflammatory markers, including erythrocyte sedimentation rate and C-reactive protein. His autoantibody profile results were normal, and radiography of his hands showed soft tissue swelling with no bone abnormalities. Therefore, the patient was diagnosed with Parkinson disease.

INTERVENTIONS

Methotrexate was discontinued, and a skin biopsy was performed, which revealed hyperkeratosis in the epidermis with thick collagenous fibers in the dermis. Therefore, the patient was informed of the benign nature of the disease and was advised to stop cracking his fingers.

OUTCOMES

After regular follow-up, there was no progression of the patient's symptoms, and repeated blood tests revealed normal results.

LESSONS

Pachydermodactyly should be considered in the differential diagnosis of painless swelling in adolescent men with normal blood testing. Early recognition of this rare benign condition helps physicians appropriately reassure the patient and his parents without exposing them to unnecessary therapy.

Pachydermodactyly: a systematic review

INTRODUCTION/OBJECTIVES

Pachydermodactyly is a rare, benign fibromatosis located around the proximal interphalangeal joints. It is often misdiagnosed as juvenile idiopathic arthritis and may cause unnecessary treatments and anxiety in patients. The goal of this paper is to describe this condition through all the existing information in the scientific literature.

METHOD

A systematic review and a descriptive study have been conducted. A systematic research was performed in PubMed, Embase, Cochrane Library and WOS.

RESULTS

Pachydermodactyly was four times more frequent in male subjects and usually started in adolescence. Bilateral presentation was more frequent. History of microtrauma in both hands due to digital manipulation was found in almost half of the patients, many of them showed some neuropsychiatric disorder. In women, the onset happened later, unilateral involvement and family history were more frequent. Swelling of soft tissue without joint implication was found in imaging tests. The progression was usually positive and the treatment included stopping the microtrauma, administrating intralesional corticoids and/or surgery.

CONCLUSIONS

Diagnosis can be established in asymptomatic young patients through a congruent physical exam, regular analytic results and imaging tests that simply show swelling of soft tissue-a biopsy is generally not required for diagnosis. As pachydermodactyly's course is asymptomatic and benign, knowledge about this condition is limited, which increases the likelihood of its underdiagnosis-it is important that clinicians know of pachydermodactyly in order to avoid misdiagnosis.