Multiple Cutaneous Reticulohistiocytoma.

Multicentric reticulohistiocytosis is a rare non-Langerhans cell histiocytosis characterized in its full form by severe destructive arthritis, cutaneous nodules, and systemic manifestations. Cutaneous lesions may precede, accompany, or more commonly develop later than other features in this disease. We describe a case of multiple cutaneous reticulohistiocytoma without any systemic associations after thorough investigations.

What was known?

Red raised lesions on the face with no systemic involvement which on histology shows diffused infiltrate of large histiocytes, with rounded nuclei, and ground glass cytoplasm. Immunohistochemistry showed CD68 positive and S-100 and CD1a negative, hence making the diagnosis of multiple cutaneous reticulohistiocytosis. Only 15 cases of only cutaneous involvement have been reported in the literature so far, our case, in addition, has only facial lesions that until date are unreported.

Introduction

Multicentric reticulohistiocytosis (MRH), which was first described in 1937[1] but named later in1954 by Goltz and Laymon,[2] is a rare non-Langerhans cell histiocytosis characterized in its full form by severe destructive arthritis, cutaneous nodules, and systemic manifestations.

Cutaneous lesions may precede, accompany, or more commonly develop later than other features in this disease. Reports of the cutaneous lesions alone (reticulohistiocytoma) have been described very rarely in the literature without associated systemic associations. They are commonly single lesions. We describe a case of multiple cutaneous reticulohistiocytoma without any systemic associations after thorough investigations.

Case Report

A 50-year-old homemaker presented with a history of multiple raised asymptomatic reddish lesions on the face of 3 months duration. They first appeared on both cheeks which with a rapid progression of 10-20 days duration involved the entire face [Figure 1a and b]. The remaining body including the ear and scalp were spared.

Figure 1

(a and b) Multiple discrete erythematous to dusky red papules on face

There was no joint pain or systemic abnormality associated with the cutaneous lesions.

On examination, multiple, discrete, erythematous to dusky red papules were noted all over the face. The rest of the body did not show any lesions. No lymph node or joint involvement was found.

General and systemic examination did not reveal any abnormalities. The clinical differential diagnosis considered were lupus miliaris disseminatus faciei and angiofibroma.

Skin biopsy showed thinning and flattening of the epidermis and the dermis showed well-circumscribed large focus of diffused dense infiltrate of large histiocytes and histiocytic giant cells scattered lymphocytes. The histiocytes had rounded vesicular nuclei and abundant pink homogenously stained ground glass cytoplasm with some of these having a foamy cytoplasm which was suggestive of reticulohistiocytoma [Figure 2a and b].

Figure 2

(a and b) Dermis shows dense infiltrate of histiocytes, giant cells and scattered lymphotcytes. the histiocytes are homogenously stained and have a ground glass appearance of cytoplasm

Among the other investigations done, serum triglyceride levels were raised to 236 mg/dl. Complete blood count, electrocardiograph, and abdominal ultrasonography did not reveal any abnormalities. Renal and hepatic functions were within the normal limits. X-ray chest and hands were normal.

Immunotyping for CD68 was positive confirming the diagnosis of reticulohistiocytoma and for S-100 and CD1a were negative. The patient was being considered for oral immunosuppressive therapy but was lost to follow-up.

Discussion

MRH, a rare granulomatous histiocytic proliferative disorder with a worldwide distribution, usually affects women in the fourth decade of life.[3] The pathogenesis of MRH is unknown; however, aberrant proliferation of the histiocytic population is postulated in response to monokines, cytokines, and other secretory products that promote macrophage proliferation and phagocytosis.[4]

In approximately 45% of patients, polyarthritis is the presenting symptom followed by cutaneous lesions.[5] In 25% of patients, skin eruption is the initial symptom and may precede arthralgia for years; and in 30% of patients, the symptoms appear simultaneously.[5] It rarely presents with multiple skin lesions without systemic disease which is then called diffuse cutaneous reticulohistiocytoma. It has been suggested that this form is the early stage of MRH.[6]

Thus our patient may either be a case of MRH prior to the onset of systemic involvement or a case of diffused cutaneous reticulohistiocytoma, which is a very rare entity.

Cutaneous lesions present as reddish-brown to flesh-toned papules and nodules, typically on the face (ears, nose) and hands (dorsal and lateral aspects of the fingers).[4] There is a predilection for hand involvement with a periungual “coral bead appearance” of lesions. Other areas of involvement are arms, legs, and mucosal surfaces. Systemic symptoms include fever, malaise, weakness, weight loss, and anorexia.[7] Rarely, the histiocytic involvement of the heart (pericarditis, heart failure), lung (bronchus, pleural effusion), and other internal organs have been reported.[4] About 28% of the patients had associated malignant tumors, most commonly bronchial, breast, stomach, and cervical carcinomas.[1]

In MRH, an association with hyperlipidemia (30–58%), positive skin tuberculin skin test (12–50%), systemic vasculitis, and autoimmune disease has been described.[47]

On histopathology, infiltration by mononucleated histiocytes as well as multinucleated giant cells with haphazardly arranged nuclei and eosinophilic, finely granulated ground glass cytoplasm dissociating collagen fibers are classically found.[1]

The strong and constant marking for antibody anti-CD68 can be considered as an essential criterion for characterizing MRH[1] which showed positivity in our case. They lack CD1a and S-100 expression, thus distinguishing them from Langerhans cell histiocytosis.[8] The disease is differentiated from xanthogranuloma, sarcoidosis, xanthomas, lymphoma, and lupus miliaris disseminates faciei by its classical histopathological features and immunotyping.

Several treatment regimens have been tried with variable success. Systemic steroids, cytotoxic drugs such as cyclophosphamide, chlorambucil, methotrexate, etanercept, infliximab, and bisphosphonates have been reported to be effective.[910]

As such, cutaneous involvement alone is very rare with only 15 cases reported in the literature so far, our case, in addition, has only facial lesions which are unreported to date to the best of our knowledge.

Declaration of patient consent

The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

What is new?

Diffused cutaneous reticulohistiocytoma or early stages of MRH involve reddish-brown to flesh toned papules and nodules on all body sites, however our case portrays such lesions only on the face.