Primary or secondary?

Paediatric dermatology

Dr. Emmanuelle Bourrat

Saint-Louis Hospital

The clinical case
Now it's your turn!
Co-prescription and advice

Clinical case presentation

The two rapidly progressive cutaneous swellings in this 13-year-old girl (left axilla and left groin), otherwise in excellent health, were resistant to topical and systemic antibiotic therapy. She underwent general surgery (excision without margins) with a histological diagnosis of undifferentiated malignant tumor requiring expert pathological review.

While awaiting slide review, clinical and paraclinical staging workup was performed (cerebral and thoracoabdominal CT, liver function tests, full blood count with blood smear, LDH), which was entirely reassuring.

The histological aspect was then clarified: infiltrate of lymphocytes, some of which were large, with CD30+ ALK- immunostaining.

The workup was completed by a bone marrow aspirate, which came back normal, and by a search for tumor cells (MRD) in the blood and bone marrow, which was negative.

Your turn

What is your diagnosis?

Select 1 answer(s) from the following choices:

Pyoderma gangrenosum

Lymphomatoid papulosis

Secondary cutaneous involvement of systemic CD30+ anaplastic lymphoma

Primary cutaneous CD30+ anaplastic large cell lymphoma

Wrong answer!

Good answer!

Selected diagnosis

This is a very rare pediatric case of primary cutaneous CD30+ anaplasticlarge cell lymphoma. The thorough staging work-up and expert pathological review enabled us to rule out two entities belonging to the same spectrum but relatively more common in children:

Lymphomatoid papulosis
Secondary cutaneous involvement of systemic CD30+ anaplastic lymphoma.

It is essential to distinguish the primary cutaneous form of CD30+ anaplastic large cell lymphoma from the systemic form: it is characterized by the absence of lymph node, visceral or bone marrow involvement, the paucilesional (often solitary lesion) and indolent nature of the lesions, and a much more favorable prognosis with the possibility of spontaneous regression. The result is a far less aggressive therapeutic approach, with topical corticosteroid therapy as first-line treatment and localized radiotherapy as second-line therapy.

Explanation of wrong answers

Pyoderma gangrenosum is a chronic, often highly progressive and painful ulceration that corresponds histologically to an aseptic neutrophilic dermo-hypodermal infiltrate.
Lymphomatoid papulosis is even rarer in children than in adults. It presents as nodules that typically progress to painless central necrosis and resolve spontaneously within a few weeks. This entity is classified as a cutaneous lymphoma and its diagnosis must be validated at a multidisciplinary team meeting.
The prognosis of a primary cutaneous lymphoma (initially developed from the lymphoid structures of the skin) is often very different from that of secondary cutaneous involvement of a systemic lymphoma (nodal or visceral), here ruled out by a negative staging workup.

Treatment

After discussion of the case at a pediatric oncology multidisciplinary team (MDT) meeting, intensive daily corticosteroid therapy (class IV) was prescribed for the pericicatricial tumoral infiltration, which reappeared rapidly after excision. Complete clinical and histological remission was rapidly achieved after a few weeks of treatment.

Message from the expert

All cutaneous lymphoproliferation, whether in adults or children, requires expert pathological review and MDT discussion to determine whether it is malignant or reactive, and its exact type.

References

^{Tomaszewski MM, Moad JC, Lupton GP. Primary cutaneous Ki-1(CD30)-positive anaplastic large cell lymphoma in childhood.J Am Acad Dermatol.}^{1999;40(5 Pt 2):857-61.}