Cutaneous Sarcomatoid B-Cell Lymphoma

Abstract

A rare case of a spindle cell (sarcomatoid) B-cell lymphoma is described. The patient, a 48-year-old male, presented with a several month history of an enlarging lesion on the scalp. Although there have been a few recent reports of cutaneous sarcomatoid lymphomas, this case is especially unusual because it presented as a scarlike plaque rather than a tumor and microscopically exhibited a prominent myxoid matrix. Given these features, the lesion was initially interpreted as an atypical fibromucinosis. The differential diagnosis included fibromucinous lesion consistent with variant of lichen myxedematosus, spindle cell carcinoma, spindle cell melanoma, atypical fibroxanthoma, and atypical smooth muscle tumors. Initial immunoperoxidase studies demonstrated negative staining for CD68, factor XIIIa, CD57, cytokeratin(AE1/AE3), S100, EMA, and vimentin, essentially ruling out the previously mentioned neoplasms. Subsequently, strong positive staining for LCA(CD45RB) and CD20 was demonstrated characteristic of a B-cell lymphoma. The patient underwent local radiotherapy with complete resolution. Although all variants of cutaneous sarcomatoid B-cell lymphomas are rare, it is imperative to consider them in the differential diagnosis of otherwise difficult to categorize spindle cell proliferations. This includes neoplasms and, based on the current case, fibromucinoses as well.

Spindle Cell Lymphoma of the Oral Cavity: A Case Report and Review of the Literature

“…23 Although not traditionally regarded as a characteristic feature of hematopoietic malignancies, a prominent myxoid change has been observed in a few unusual cases of spindle cell B-cell lymphoma and sarcomatoid leukemia. 1,2,12,22 Such myxoid features may contribute further to a false impression of sarcoma. In addition, in a case of cutaneous spindle cell B-cell lymphoma reported by Ries et al, 12 a prominent myxoid matrix led to the consideration of lichen myxedematosus in the differential diagnosis.…”

“…[1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] A summary of the salient clinicopathologic features of these cases and the present case is presented in Table 1. The present review was limited to cases in which there was prominent spindle cell morphology among the lymphoid cells themselves, rather than the surrounding stromal cells.…”

“…The skin lesions appeared as single or clustered nodules, papules, or plaques; ulceration, pruritus, erythema, and poorly defined borders were noted in some cases. 3,4,7,8,11,12,15,16 Additional head and neck involvement included the submandibular soft tissue, orbit, sinonasal mucosa, salivary gland, and mandible/ overlying gingiva (n ϭ 1 for each of these sites). Other locations included the chest wall (n ϭ 3), vagina/ uterus/parametrium (n ϭ 3), mediastinum/mediastinal lymph nodes (n ϭ 3), inguinal soft tissue/inguinal lymph nodes (n ϭ 2), liver (n ϭ 2), kidney (n ϭ 1), retroperitoneum (n ϭ 1), testis/epididymis (n ϭ 1), and para-aortic lymph nodes (n ϭ 1).…”

“…1,2,12 The initial microscopic impression was stated in 12 cases and included soft tissue sarcoma (n ϭ 5; including unspecified type, dermatofibrosarcoma protuberans, and malignant fibrous histiocytoma), spindle cell carcinoma (n ϭ 3), inflammatory pseudotumor (n ϭ 1), atypical fibroxanthoma (n ϭ 2), melanoma (n ϭ 2), lym- phoma (n ϭ 2), lichen myxedematosus (n ϭ 1), follicular dendritic cell sarcoma (n ϭ 1), and osteosarcoma (present case). 1,4,6,7,12,13 Immunohistochemical stains generally showed positive reactivity for CD45 (17 of 17 cases) and B-cell markers, including CD20 (26 of 26 cases) and CD79a (13 of 13 cases). Bcl-6 was positive in 11 of 11 cases; results were variable for CD10 (5 of 11 positive cases) and Bcl-2 (3 of 8 positive cases).…”

“…However, spindle cell variants of B-cell lymphomas have rarely been reported. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] Many such cases have been described as cutaneous spindle cell B-cell lymphomas, which typically present as solitary or clustered skin nodules with a predilection for the skin of the head, neck, and back. 3,16 The origin of spindle cell B-cell lymphomas is uncertain, with previous investigators favoring classification as a variant of follicular lymphoma or diffuse large B-cell lymphoma.…”