A rare case of primary cutaneous follicle centre lymphoma presenting as a giant tumour of the scalp and combined with JAK2V617F positive essential thrombocythaemia

Abstract

Primary cutaneous follicle centre lymphoma (PCFCL) is a rare cutaneous B cell lymphoma in middle-age adults with excellent prognosis. Here we present a case of a patient with a PCFCL in the form of a giant tumour of the scalp in combination with a myeloproliferative neoplasm, JAK2V617F positive essential thrombocythaemia. This case may be of interest because of the favourable outcome in spite of the large size of the PCFCL, the rare combination with essential thrombocythaemia and because it contributes to discussion on the role of JAK2 mutation in such patients.

Figure 1

Multinodular mass on the scalp (A) and spectacular response after the second chemotherapy course (B).

Figure 2

Histopatological fingings. Biopsy of the mass of the scalp showing a dense and diffuse dermal infiltrate with nodular growth pattern (A) consisted of large atypical lymphocytes (H&E) (B), which are positive for CD20 (C) and Bcl6 (D) and negative for Bcl2 (E) on immunohistochemical staining. Bone marrow biopsy showing a hypercellular bone marrow with proliferation of megakaryocytes with hyperlobulated nuclei, sometimes in loose clusters (H&E) (F), positive for CD61 on immunohistochemical staining (G).

Figure 3

Radiological investigations showing the lesions before treatment and their evolution after the treatment. MRI at diagnosis (A), (B); PET-CT at diagnosis (C), (D); PET-CT and MRI after 2 cycles of R-CHOP (E), (F).