Multiple firm nodules in a young woman: an unusual presentation of sarcoidosis

Abstract

A 27-year-old woman presented to the dermatology department with a 1-year history of multiple asymptomatic violaceous lesions on her upper and lower extremities, trunk and abdomen. The lesions were firm on palpation. She had no other associated symptoms and the rest of the examination was unremarkable. An incisional biopsy showed multiple confluent granulomas composed of histiocytes devoid of necrosis surrounded by a rim of lymphocytes extending to the subcutaneous fat consistent with the diagnosis of subcutaneous sarcoidosis. The serum ACE assay was elevated at 134 IU/L. Other blood tests including complete blood count, renal and liver function tests, serum calcium and phosphate were within normal ranges and chest X-ray was unremarkable. Complete remission was achieved with an intralesional triamcinolone injection (10 mg/mL) for a few sessions. Subcutaneous sarcoidosis is a rare variation and its diagnosis requires a high index of suspicion.

Background

Panniculitis is a group of adipose tissue disorders with subcutaneous fat tissue inflammation that may appear as a rare presentation of sarcoidosis. This report describes a case of panniculitis in a patient with subcutaneous sarcoidosis that manifested as gradual progression of multiple firm nodules on the upper extremities, trunk and abdomen. Although a strong association between subcutaneous sarcoidosis and systemic involvement is usual, our patient had no systemic involvements and was treated successfully with intralesional corticosteroids alone.

Case presentation

A 27-year-old woman presented with 1-year history of multiple violaceous lesions on her left arm, upper back, abdomen and right thigh for approximately 1 year. Initially, the lesions appeared on her left arm with gradual progression to other parts of her body (figure 1). These lesions had no other specific symptoms. She was otherwise healthy and had no significant medical history. Examination showed multiple ill-defined and non-tender violaceous patches which were firm nodules on palpation. The overlying skin of the lesions was normal and there was neither atrophy nor ulcer. She had no fever or lymphadenopathy.

Figure 1.

Violaceous patch on the left arm which palpation revealed a subcutaneous firm nodule.

Investigations

An incisional biopsy from the lesion of her left arm was performed. Histopathological assessment revealed multiple confluent granulomas composed of histiocytes devoid of necrosis surrounded by a rim of lymphocytes extending to subcutaneous fat inducing granulomatous panniculitis. The panniculitis showed mixed septal and lobular type with a predominantly lobular pattern. No vasculitis was seen and no necrobiosis and caseous necrosis were identified. The Gram and acid-fast stainings did not reveal any evidence of infection. Special staining including PAS and silver stain failed to reveal fungal organisms (figure 2). The cultures for mycology and mycobacterium came back negative. Serum ACE assay was elevated at 134 IU/L (normal range, 8–54 U/L). Other parameters including complete blood count, renal and liver function tests, serum calcium and phosphorus were within normal ranges and chest X-ray was unremarkable.

Figure 2.

Two granulomas with well-defined contour in subcutaneous fat tissue composed of predominantly histiocytes and epithelioid cells surrounded by rim of mature small lymphocytes. No necrobiosis or caseous necrosis is identified (H&E, ×20).

Differential diagnosis

Differential diagnosis of subcutaneous sarcoidosis include other causes of multiple pure subcutaneous nodules which have a firm consistency. Epidermal cysts, lipomas, calcinosis, rheumatoid nodules, cutaneous metastasis, erythema nodosum and less frequent lesions such as tuberculosis and deep mycoses must be excluded.¹

Treatment

Although a strong association between subcutaneous sarcoidosis and systemic involvement is usual, our patient did not have any signs of systemic involvement. This patient was successfully managed with intralesional triamcinolone (10 mg/mL) for three sessions at monthly intervals.

Outcome and follow-up

Following treatment with intralesional triamcinolone, our patient had a complete remission of lesions with no side effects. She did not develop any systemic manifestations of sarcoidosis on subsequent follow-up for 6 months.

Discussion

Subcutaneous sarcoidosis is a rare clinical condition that develops in patients with systemic sarcoidosis in 1.4% to 6% of cases.¹ It was first described by Darier and Roussy in 1904, and it is also known as Darier-Roussy sarcoid.² Vainsencher and Winkelmann proposed the diagnostic criteria in 1984, defined by the epithelioid or sarcoidal granulomas with minimal lymphocytic inflammation involving predominantly the panniculus.¹ Fewer than 100 cases of subcutaneous sarcoidosis have been reported to date.³ This phenomenon mostly occurs in women especially during the fourth decade.⁴ Subcutaneous sarcoidosis is mainly manifested by hard indurated subcutaneous nodules with asymmetric distribution.³ They are multiple (ranges from 1 to 100) with an average size of 0.5 to 2 cm, firm, asymptomatic to slightly tender, mobile, round to oval, skin-coloured nodules and are commonly located on the extremities (forearms and legs), usually in a bilateral and asymmetric fashion. The trunk, face, buttocks, head and neck are the other sites of involvment.^{1 3} Subcutaneous sarcoidosis is one of the most uncommon cutaneous manifestations of sarcoidosis and its diagnosis needs a high index of suspicion. Unlike erythema nodosum, the lesions of subcutaneous sarcoidosis persist for a longer period of time.¹

It has been observed that there is a strong association between subcutaneous sarcoidosis and systemic disease in particular bilateral hilar lymphadenopathy (72.7%), followed by lung infiltrates, parotitis, uveitis, arthritis/arthralgia, mucositis, neurological and renal involvement, and hepatosplenomegaly.^{3 4}

Co-occurrence of subcutaneous sarcoidosis and other manifestation of cutaneous sarcoidosis has been noted and an association between this form of sarcoidosis and autoimmune diseases such as thyroiditis, vitiligo, pernicious anaemia, rheumatoid arthritis, ulcerative colitis, systemic lupus erythematosus, sicca syndrome and Cushing syndrome was reported.^{4 5}

Histological examination of subcutaneous sarcoidosis shows a non-caseating epithelioid granulomas with multi-nucleated giant cells and lymphocytic inflammation with the extension to the panniculus.⁴ Along with histological assessment for the diagnosis of subcutaneous sarcoidosis, using special stains should be considered to rule out the other etiologies of granulomas. The mainstay of treatment for subcutaneous sarcoidosis is based on oral glucocorticoids (20–40 mg daily) when the number of lesions are significant or there is a systemic involvement. The response occurs up to 4 to 8 weeks after treatment initiation.^{4 6} The additional treatments include non-steroidal anti-inflammatory drugs, methotrexate, intralesional glucocorticoids, hydroxychloroquine, allopurinol, minocycline and potassium iodide.^{1 3 7}

Learning points.

• Subcutaneous sarcoidosis is a rare manifestation of cutaneous sarcoidosis and its diagnosis needs a high index of suspicion.

• Comprehensive examination and investigations are required to rule out systemic sarcoidosis.

• There may be an association between subcutaneous sarcoidosis and autoimmune diseases.