Pneumologie 2015; 69 - P20
DOI: 10.1055/s-0035-1551922

Arthritis and tenosynovitis, skin and renal localization as manifestations at onset of sarcoidosis: role of the whole-body PET

A Triani 1
  • 1Pneumology Service of the South Tyrolean Health Care, Austria

Introduction:

Sarcoidosis is characterized by a granulomatous inflammatory reaction that usually presents with mediastinal and hilar lymphadenopathy and with variable involvement of the lungs. Other organs may be involved, including the skin, kidneys, liver, salivary glands, and bone marrow. The reported incidence of bone involvement varies but may be more common in patients with musculoskeletal complaints.

If arthritis is a frequent complication (23%), tenosynovitis is a rare sign of onset of sarcoidosis.

We report a case of proliferative tenosynovitis of the hands and ankles in sarcoidosis and the suggestive role of PET scan, FDG Positron Emission Tomography, to detect the Bone involvement in sarcoidosis.

Case Report:

Male 37 years comes to pulmonary visit in 2010 for cough associated with asthenia, anorexia, weight loss, night sweats, skin nodules and brownish facial pain and swelling from 2 years to fingers and ankles (Fig. a-b-c-d).

MRI requested any months before the visit, showed marked proliferative tenosynovitis of the hands and ankles for which occasionally took NSAIDs. (Fig. 1 – 2-3 – 4).

Requested exams:

Chest radiography performed at admission: magnification bilateral lymphadenopathy especially on the left (Fig. 5). Because we took lymphoma or TB on differential diagnosis, the patient was referred for whole-body FDG PET-CT.

PET-CT: Whole-body PET was performed 60 min after the IV administration of 6 mCi (222 mBq) of FDG using an GEMINI TF PET/CT scanner. Transmission images were acquired for 3 min per table position. Standardized uptake values were calculated using the commercially available algorithm.

PET showed increased uptake in the soft tissue and in the articulation, paratracheal, prevascular, Barety and Azygos lodge and subcarinal. Focal bone uptake was seen in the hands, and feet.

The low uptake value of the lesions and their pattern of distribution were not suggestive of malignant disease, so the findings were interpreted as inflammatory (Fig. 6).

Helical CT of the chest showed mediastinal lymphadenopathy involving the paratracheal compartment, the aortopulmonary window, the precarinal and subcarinal nodules. Multiple small pulmonary nodules were seen in the left lung.

Radiography of hands and feet: alterations of sarcoidotics Jüngling with osteolysis in the variety "mutilating."

The Bronchoscopy was normal and carinal biopsy were negative. BAL 42/100 ml; 30,000,000 cells, macrophages 46.5%, 49.5% lymphocytes, neutrophils 4%, CD4 81%, CD8 16%. ACE 52 U/l (8.0 – 52), ESR 28, serum calcium 9.6; urinary calcium 263 mg/24h (normal 100 – 250), PCR 0.34; PPD 5UI to 72 hours 0 × 0 mm.

Skin biopsy: cutaneous sarcoidosis, demonstrating the presence of ill-defined noncaseating granulomas.

Therapy:

Prednisone 50 mg for 6 weeks then reduced and associated with Plaquenil 200 mg/day and Methotrexate 10 mg/week with regression of events.

Discussion:

FDG PET is useful in the diagnosis and treatment of a variety of malignancies. PET can also play a major role in the diagnosis of patients with suspected infection and inflammation. The uptake of FDG increases when metabolic activity is increased by inflammatory cells. In sarcoidosis, macrophages are activated and play an important role in the formation of granulomas, which may explain why the granulomatous lesions of sarcoidosis show strong FDG uptake. In sarcoidosis, the degree of FDG uptake has been related both to activity of disease and to treatment responsiveness. Other researchers have described the intense uptake of FDG in sarcoidosis, particularly in the associated lymphadenopathy. In our experience the uptake of bone involvement seen on FDG PET was totally confirmed with bone radiography.

Tenosynovitis was related to sarcoidosis. The patient's previous medical history easily induced to assume a tenosynovitis associated with sarcoidosis.

In our patient the disease was chronic, never treated, commitment to multi-organ failure.

Conclusions:

In sarcoidosis, there are rare cases of tenosynovitis as a sign of onset. This case report suggests that the diagnosis of sarcoidosis should be considered before a proliferating polyarticular tenosynovitis.

In conclusion, our case shows that FDG PET may be a sensitive tool for evaluating the extent of sarcoidosis in bone involvement.