Widespread primary cutaneous diffuse large B‐cell lymphoma, leg type, with nasal involvement

Dear Editors,

1.

Primary cutaneous diffuse large B‐cell lymphoma, leg type (PCDLBCL‐LT) is a type of cutaneous B‐cell lymphoma that presents itself as solitary or confluent violaceous‐red plaques and nodules primarily on the lower extremities of elderly patients.1 However, PCDLBCL‐LT may also develop in body sites other than legs in 10% to 20% of cases.2 Although PCDLBCL‐LT remains limited to the skin in most of patients, there may be further involvement of lymph nodes and bone marrow.1 Here, we would like to present a unique case of PCDLBCL‐LT developing on both the upper and lower extremities, as well as having nasal mucosal extension.

An 89‐year‐old man was admitted to our Dermatology outpatient clinic for gradually growing violaceous, erythematous, indurated, shiny tumours, plaques, and nodules involving multiple body sites. Dermatological examination demonstrated erythematous/violaceous, confluent, indurated plaques and nodules accompanied by hyperkeratinisation, crust formation, and serosanguinous discharge localised on the dorsal part of the right foot, both his lower legs, and forearms (Figures 1, 2, and 3).

Figure 1.

Erythematous‐violaceous, confluent, indurated plaques and nodules accompanied by some hyperkeratinisation on the dorsal part of right foot (A) and its closer view (B)

Figure 2.

A, Purple, erythematous dome‐shaped nodules and hyperkeratotic, crusted tumour formation on left leg. B, Similar hyperkeratotic tumour is also observed on left lateral forearm

Figure 3.

Erythematous‐based hyperkeratotic tumour is seen on the extensor surface of right arm (A) accompanied by bleeding (B)

Skin biopsy performed in another medical institution demonstrated histopathological findings consistent with Bcl‐2(+), CD20(+), CD30(−), and atypical B‐cell lymphoid proliferation. No staging procedures, such as bone marrow biopsy (BMA/B), positron emission tomography‐computed tomography (PET‐CT), and lymph node ultrasonography (LNUSG), were performed. At that time, neither a nasal bulk nor any airway obstruction symptoms were present or noticed by the patient. No medical therapy was initiated.

Approximately 1 year after the appearance of the first cutaneous nodule, he was referred to our Dermatology outpatient clinic because of recently appearing, enlarging, ulcerating nodules. A 4‐mm punch biopsy taken from the right ankle and right anterior arm demonstrated multiple neoplastic lymphoid B‐cells with round nuclei, prominent nucleoli, broad cytoplasm, and high mitotic activity (Figure 4). The skin biopsy also showed some scattered CD3(+), CD4(+), CD8(+), and granzyme B(+) T lymphocytes among lymphoid B‐cells. Immunohistochemistry (IHC) studies showed that neoplastic cells were Bcl‐2(+), CD20(+), MUM1(+), and IgM(+) but CD56(−), CD23(−), CD10(−), Bcl‐6(−), CD30(−), and ALK(−) (Figure 4). T cells within the infiltrate were CD3(+), CD4(+), CD8(+), and granzyme B(+). Ki67 proliferation index was 50% to 60%. On histological and IHC findings, a diagnosis of high grade B‐cell lymphoma, PCDLBCL‐LT was confirmed.

Figure 4.

A, Low power demonstrates a neoplastic infiltrate with a diffuse growth pattern filling the dermis (×40). B, At high power, the infiltrate is composed of monotonous round cells with blastic chromatin and smooth nuclear contours, and mitotic figures can be readily seen (×200). The neoplastic cells were positive with CD20 (×200), IgM (×200), Bcl‐2 (×200), and MUM‐1 (×200). They did not stain with CD10 (×200) and Bcl‐6 (×200)

To exclude a systemic lymphoma, PET‐CT, LNUSG, and BMA/B were performed. LNUSG and BMA/B were normal. PET‐CT detected pathological F‐18 fluorodeoxyglucose (FDG) uptake in the right nasal mucosa involving the nasal vestibule and multiple focal density enhancements in the cutaneous/subcutaneous regions of the upper and lower extremities compatible with the location of nodules (Figure 5). There was no further FDG uptake extending to the other areas of nasal cavity. Rhinoscopic examination detected a bulk in only the right nasal vestibular area, protruding outside the right nostril. Subsequently, an incisional biopsy was carried out from the nasal mass. The histopathological features were similar to those of cutaneous lesions, which were consistent with the secondary spread of PCDLBCL‐LT to the nasal mucosa.

Figure 5.

Positron emission tomography‐computed tomography detected multiple focal density enhancements in the cutaneous/subcutaneous regions of the upper (A, B) and lower extremities (C) and pathological fluorodeoxyglucose uptake in the right nasal area with a maximum standardised uptake value of 13.9 (D)

A chemotherapy regimen, including rituximab, vincristine, and prednisone, was initiated. After second round of chemotherapy, regression observed in both the size and number of the cutaneous nodules and nasal mucosal bulk was quite remarkable.

PCDLBCL‐LT is a type of primary cutaneous B‐cell lymphoma, which may involve any body part.1 Osada et al reported a patient diagnosed with PCDLBCL‐LT localised in the right periorbital region.3 In addition, spread of the disease to the lymph nodes and internal organs can also be observed.4 We argue that our case presents an example of PCDLBCL‐LT with secondary spread to nasal mucosa given that cutaneous lesions appeared 1 year before nasal mucosal bulk and airway obstruction symptoms were detected. In addition, quick response to chemotherapy favours the diagnosis of PCDLBCL‐LT instead of secondary cutaneous spread of systemic non‐Hodgkin diffuse large B‐cell lymphoma originating from nasal mucosa. Previously, a case of PCDLBCL‐LT with secondary spread to ureter was reported.5 In our patient, consistent with PET‐CT findings, rhinoscopy demonstrated a mass involving the right nasal mucosa that was confirmed to be secondary mucosal involvement of PCDLBCL‐LT.

Here, we report an exclusive case of PCDLBCL‐LT presenting on both the lower and upper extremities with nasal mucosal involvement, which showed a very rapid response to rituximab, prednisone, and vincristine treatment.

CONFLICT OF INTEREST

The authors declare no potential conflict of interest.