Adult Onset of Xanthelasmoid Mastocytosis: Report of a Rare Entity.

Xanthelasmoid or pseudoxanthomatous mastocytosis is an extremely rare variant of diffuse cutaneous mastocytosis. Herein, we describe an adult male with cutaneous mastocytosis showing multiple widespread yellowish ovoid papules like eruptive xanthoma. A 60-year-old male visited our outpatient clinic with a 1-year history of generalized yellowish, ovoid, and skin color papular eruption located on the trunk, groin, extremities, with the modest pruritus. Vital signs were stable, and Darier's sign was negative. No other subjective and objective signs were detected during the examination. No abnormality was detected in his diagnostic laboratory tests. Skin biopsy was taken, and histopathologic examination revealed proliferation of mast cells with ovoid and spindle nuclei with distinct cytoplasm borders around the capillaries, which was compatible with mastocytosis. Antihistamine was prescribed for pruritus control which was successful, but eruptions were persistent, and even 1-year phototherapy was not useful.

What was known?

The majority of mastocytosis appears in the childhood in which urticaria pigmentosa and mastocytoma are the most common types. Some variant of diffuse cutaneous mastocytosis like pseudoxanthomatous mastocytosis or xanthelasmoid are extremely rare, especially in the adult.

Introduction

Mastocytosis is a group of disease that characterized by increased the population of mast cells in many organs such as skin, bone marrow, liver, spleen, and lymph nodes which among the skin is the most common involved organ.[1] The majority of mastocytosis appears in childhood and urticaria pigmentosa (UP), and mastocytoma are the most common types.[2] The most presentation in adults are red-brown macules and papules on the trunk and proximal limbs.[3] Other presentation such as telangiectasia macularis eruptive perstans and diffuse cutaneous mastocytosis (DCM) are rare in adults.[2] The term xanthelasmoid, nodular, and pseudoxanthomatous mastocytocytosis describe all the same clinical condition with slight variations, therefore, could be considered as synonyms and have been introduced to describe the presence of yellowish papular or nodular lesion.[12] Herein, we describe an adult male with cutaneous mastocytosis showing multiple pruritic widespread skin colored to yellow ovoid papules like eruptive xanthoma.

Case Report

A 60-year-old male visited our outpatient clinic with a 1-year history of generalized yellowish ovoid, and skin color papular eruption located on the trunk, groin, and extremities. He first noticed pruritic papules, and 2–3 months later many yellow and ovoid pruritic papules emerged. Medical history, family history, and social history of the patient were all negative. He denied taking any medications before admission and there was no apparent episode of any infection before the onset of the eruption. Patient's adverse drug reaction history was also negative.

On skin physical examination firm, well-defined ovoid skin colored to yellow papules were seen on the distal and proximal of upper and lower extremities, trunk, groins, and abdomen [Figure 1a and b].

Figure 1

(a) Multiple eruptive firms, ovoid, and well-defined papules on the distal and proximal of upper extremities, trunk, and the abdomen. (b) The close up of papules with the skin to yellowish color

Lesions were in different evolutionary stages varying in size from 2 to 5 mm. Palms, soles, face, and mucous membranes were spared. Vital signs such as blood pressure, respiratory rate, and heart rate of the patient were stable, and the temperature was 36.9°C. Pruritus was modest, and Darier's sign was negative. He had no other symptoms such as bone pain, weight loss, fatigue, and abdominal discomfort. Also, no adenopathy or other objective signs were detected during the physical examination. Diagnostic laboratory tests such as full blood cell count with differential, peripheral blood smear, renal, and liver function tests all were normal.

Investigations was continued by histopathological examination of the skin biopsy from one of the lesion on the trunk revealed proliferation of mast cells with ovoid and spindle nuclei with distinct cytoplasm borders around capillaries, which was compatible mastocytosis [Figure 2a and b]. Giemsa staining showed metachromatic granules in the cytoplasm. Based on concurrent clinical and pathological features, we diagnosed our case as xanthelasmoid mastocytosis. Bone marrow biopsy was advised him, but the patient did not have any desire to do. H1 antihistamine, cetirizine 10 mg orally nightly and fexofenadine 120 mg for every morning was prescribed for pruritus control which was successful, but eruptions were persistent without any changes. Treatment with phototherapy recommended to the patient but despite 1-year course, no significant improvement was seen in the lesions.

Figure 2

Proliferation of mast cells with ovoid and spindle nuclei with distinct cytoplasm borders around capillaries. (H and E, [a] ×10 and [b] ×100)

Discussion

There are four clinical variants for cutaneous mastocytosis: UP, telangiectasia macularis eruptiva perstans, solitary mastocytoma, and DCM.[2] Xanthelasmoid or pseudoxanthomatous mastocytosis is an extremely rare variant of DCM.[1245] It was first described in 1875 by Fox with the term of “xanthelasmoid mastocytosis.”[6] The exact prevalence of the xanthelasmoid mastocytosis is not clear but in a study in 1923, prevalence of 8% was estimated at that time, and in another study in 1999, 25% of children with UP and mastocytoma showed a pattern of xanthelasmoid form.[1245] It is characterized with the multiple yellowish papules resembling both xanthoma and pseudoxanthomatous elasticum.[6] Until 1893, Colcott collected 19 other similar cases; although all of them were in the ranging ages of 3 days to 5 months.[7] The similar presentation of this group of patients was a brown macules or patches or “brownish-drab rounded areas,” which was different from our patient.

Our case was remarkable because of the age of onset, the severity of the cutaneous involvement and though lesions were on the process of evolution, there were no pigmented macular lesions, as different and well defined types of lesions may coexist. Based on the best of our knowledge, the acute presentation of xanthelasmoid mastocytosis has not been reported in the adult population, yet. The frequency of DCM has been reported by Lange et al.[1] Based on Gdansk Center registry, this type of mastocytosis was just revealed in 10 of 280 of mastocytosis patients.[1] They just reported one adult with DCM; however, the onset of the cutaneous involvement was in his childhood as other reports.[8] In another report by Chraibi et al., a 20 years French female has been diagnosed with xanthelasmoid mastocytosis.[9] By the way; we can find out that the presented case is the only DCM with adult onset in men.

As in our case, Darier's sign is often negative in xanthelasmoid mastocytosis. Unlike macular forms the infiltration of mast cells in xanthelasmoid forms predominantly affecting the deep dermis. So, this could be a reason for the yellowish color of the lesions.[24]

One of the concerns about the DCM in pediatric patients is its association with systemic symptoms, such as severe diarrhea, gastrointestinal manifestations, shock, and hypotension because of the much higher concentration of mast cells.[310] But, in our patient, no systemic symptoms were observed during the hospital stay and inpatient visits. On the other hand, since the high incidence of systemic symptoms in pediatric patients with DCM, this presentation is considered with a poor prognosis and consequently a closer long-term follow-up; however, our patient evaluated completely without any major complications till now.[4] So, it seems that the prognosis of adult patients might be different with pediatric patients. Indeed, we should noticed that like other variant of cutaneous mastocytosis, the prognosis of this form is dependent on the age of onset and systemic involvement.[5] In adults, the risk of persistence of lesions and extracutaneous involvement is more common.[211]

Treatment of xanthelasmoid mastocytosis is resembled of other forms of cutaneous mastocytosis. Avoidance of mast cell degranulation agents such as aspirin, codeine, stress, trauma, temperature changes, and certain foods is the most important component of the treatment. Other treatment options include antihistamines, topical or systemic corticosteroids, mast cell stabilizer, PUVA therapy, and interferons.[51112] Antihistamines was prescribed for pruritus control was successful, but eruptions were persistent without any changes and despite 1-year phototherapy, no significant improvement was seen in the lesions.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

What is new?

Pseudoxanthomatous mastocytocytosis is a rare variant, and our case was remarkable because of the adult age of onset and the severity of the cutaneous involvement. To the best of our knowledge, the acute presentation of xanthelasmoid mastocytosis has not been reported in the adult male population, yet.