Cytologic features of abscessified anaplastic large cell lymphoma.

Sir,

The cytologic features of anaplastic large cell lymphoma (ALCL) have been well characterized, including the neutrophil-rich variant.[12] This morphologic variant shows an extensive neutrophilic infiltration sometimes accompanied by eosinophils in the absence of necrosis.[2] Neutrophilia is not secondary to tumor necrosis or abscessification and probably relates to the production of chemoattractants by neoplastic cells.[2] When reviewing the cytologic reports describing ALCL, it is often said that a background of neutrophils is present, but only in two patients it is referred as abundant, capable of obscuring the neoplastic cells.[34] In both cases diagnostic difficulties were present. Whether related or not to necrosis the abundance of neutrophils creates an abscess-like image that complicates diagnosis. Here we describe a further case of abscessified, suppurative ALCL associated to tumor necrosis. Cellular cohesiveness and anaplasia coupled with numerous neutrophils and an atypical clinical presentation resulted in a misdiagnosis of carcinoma. The patient, a 50-year-old woman was being evaluated because of a nodule in the axillary prolongation of left breast. In addition, image studies revealed ipsilateral axillary adenopathies and the possibility of breast carcinoma with metastases was considered. With this presumptive diagnosis, the patient underwent fine needle aspiration cytology with ultrasonographic guidance of an axillary lymph node. A cytological diagnosis of “metastatic abscessified, anaplastic carcinoma” was made. A trucut biopsy of the lesion located in the axillary prolongation of the breast was performed. It showed a neoplasm with solid growth pattern composed of large anaplastic cells intermixed with abundant neutrophils, eosinophils and necrosis. Immunohistochemical study showed no expression of cytokeratins AE1/AE3 or hormonal receptors. A second study revealed intense expression of epithelial membrane antigen and CD30 with variable expression of CD3 and negativity for CD45, CD20, cytokeratin 7, protein S100 and Melan A. There was no expression of CD15, CD5, CD10, or ALK protein. A diagnosis of ALK negative ALCL was established and cytologic smears were reviewed. These were dominated by neutrophils and necrotic material with a small population of large neoplastic cells. These were restricted to a small area of the smears while most of them showed an abcessified image devoid of tumoral cells. These were pleomorphic with moderate-to-abundant, deeply stained cytoplasm with occasional microvacuoles [Figure 1]. Most cells had a round to epithelioid morphology with occasional ones with spindle, "hand mirror" shape. Neoplastic nuclei were pleomorphic with a predominance of round and reniform shapes with frequent binucleation and prominent nucleoli. Most neoplastic cells were distributed singly but a few cellular groups of small to medium size were also present [Figure 2]. A scarce subpopulation of small, reactive-like lymphocytes was present with few lymphoglandular bodies.

Figure 1

Neutrophils and necrotic material are abundant creating and abscessified-like image. In addition, large anaplastic cells, one of which shows an elongated morphology, are present (Diff-Quik, ×200)

Figure 2

In some areas neoplastic cells showed evident cell-clustering mimicking carcinoma. Mitotic activity and cytoplasmic microvacuolization are present. Lymphoglandular bodies are scarce (Diff-Quik, ×400)

The cytology of ALCL is peculiar among non-Hodgkin's malignant lymphomas. Prominent pleomorphism, abundant cytoplasm, cell clustering, and scarcity of lymphoglandular bodies often result in confusion with carcinoma.[1] Diagnostic difficulties can be greater when abundant neutrophils and/or necrosis are present. In the series published by Rapkiewitcz et al,[3] a case of suppurative ALCL in which differentiation from anaplastic carcinoma or melanoma was not possible is described. In the case reported by Tamiolakis et al,[4] the abundance of neutrophils led to an erroneous cytological diagnosis of lymphadenitis. Despite our diagnostic error, we consider that the present case showed cytologic features characteristic of ALCL, including abundant cytoplasm, hallmark cells with reniform nuclei, large nucleoli, plasmocytoid and “hand mirror” cells. In our opinion, the clinical context with suspicion of breast carcinoma, presence of cellular aggregates and suppurative changes were responsible for misdiagnosis. In addition to abscessified carcinoma, Hodgkin's lymphoma should be also considered since it may present cytologically with numerous neutrophils and necrosis.[5] In conclusion, abundant neutrophils either accompanied or not by necrosis should be added to the cytomorphologic spectrum of ALCL. When prominent, suppurative changes can complicate the already difficult cytologic recognition of ALCL.