ISR Autumn Meeting 2018

Oral Case Award

Dr Leah Rooney

TBA (18A184)

A case of bony swelling in an otherwise well man.

Author(s)

Dr Leah Rooney, Dr Shawn Chavrimootoo, Dr S A Ramakrishnan

Department(s)/Institutions

Department of Rheumatology, Our Lady’s Hospital, Navan.

Introduction

A 51-year-old man attended a rheumatology clinic with a 2-year history of hand pain and swelling. His past medical history was significant for Granuloma Annulare that had been diagnosed by his GP 4 years earlier and since then the skin lesions have persisted.
On examination he had bony swellings in his intermediate phalanges in his 3rd and 4th digits on his left hand and in his 1st distal phalanx on his right hand. He had no tenderness over these areas. His joint exam was unremarkable with no detected synovitis. Skin examination showed raised erythematous annular lesions on his face, scalp, and neck.

Aims/Background

To diagnose the cause of the bony swelling.

Method

His basic investigations were unremarkable. They revealed normal inflammatory markers, negative rheumatoid factor and Anti CCP, normal calcium and alkaline phosphatase. The X-Ray of his hands and chest X-ray were both normal.
He went on to have further investigation with an MRI of his hands. This showed diffusely abnormal bone marrow signal within multiple phalanges.

Results

The differential diagnosis included psoriatic dactylitis, atypical infection and sarcoidosis.
A biopsy of one of the affected phalanges showed well-formed granulomas. A diagnosis of osseous sarcoidosis was made and he started treatment: oral methotrexate. His awaiting a skin biopsy.

Conclusions

Osseous involvement is an uncommon primary presentation of sarcoidosis. Most cases occur after a long disease process and 90% of the patients have had pulmonary involvement. The reported frequency of osseous involvement among patients with sarcoidosis is 3-13%. However this may be underestimated as 50% of osseous sarcoid is asymptomatic.
Initially, osseous sarcoid was most commonly reported as affecting the small bones of the hands and feet, but 2 case series in 2014 and 2017 report a higher incidence of lesions in the pelvis and spine, likely due to a higher pick up rate with the increasing use of PET/CT and MRI imaging.
X-rays can show lytic, sclerotic, or mixed lesions. But – as in this case – X-rays can be normal. To proceed, an MRI or PET-CT scan is useful. MRI can also be used to monitor lesions, and PET/CT can show the distribution of the lesions. To make the diagnosis, a bone biopsy is required to confirm the presence of non-caseating granulomas and to distinguish osseous sarcoid from bone metastasis - they can look similar on imaging.
There is no general consensus or guidelines on treatment for osseous sarcoid. Asymptomatic patients do not always require treatment and the bone lesions detected on imaging can improve or resolve without treatment. For symptomatic patients, the most commonly used treatment in published case reports is corticosteroids. Also, Methotrexate and Hydroxychloroquine are used frequently and with success, and Anti TNF has been effective for refractory symptomatic Osseous Sarcoidosis. Among those who are treated, most patients do not require long-term treatment.
Our patient had a prior diagnosis of granuloma annulare. Granuloma annulare can be seen in association with neoplastic and autoimmune diseases, including sarcoidosis. There are many case reports describing a link between the 2 conditions. However, cutaneous sarcoid can uncommonly present with annular eruptions and can be misdiagnosed as Granuloma Annulare.


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