Anaplastic large cell lymphoma with a small cell pattern is a rare T-cell lymphoma. This condition is more frequently seen in younger patients and should be considered when patients present with leucocytosis and constitutional symptoms. In this report, we describe our diagnostic work-up for one such case using blood, lymph node, and bone marrow aspirate samples, highlighting the variability of antigen expression seen in different sample types and methodologies. This case shows the importance of having a high index of suspicion and assessing CD30 and anaplastic lymphoma kinase expression in all suspected T-cell neoplasms even though this rare condition is not necessarily expected. 1. Introduction Anaplastic large cell lymphoma (ALCL) anaplastic lymphoma kinase positive (ALK+) is one of the subcategories of the mature T-cell neoplasms [1]. ALCL, ALK+ accounts for approximately 3% of cases of adult non-Hodgkin lymphomas and 10–20% of childhood lymphomas. There are many morphological variants of ALCL of which the small cell pattern variant accounts for 5–10% of cases. In this rare subtype, leukaemic manifestation is commonly seen in contrast to the other morphological variants [1–3]. Clonal T-cell populations may be demonstrated in the peripheral blood in a variety of clinical conditions. Although lymphocyte morphology may be indicative of a specific pathology, phenotyping of the population of interest is valuable in establishing the diagnosis. The apparent phenotype however may vary depending on technique, sample type, and cell population analysed. It is therefore essential to correlate phenotypic information with genetics and clinical presentation. 2. Case Presentation A 22-year-old female presented to her local hospital with a 16-day history of fevers, night sweats, nausea, and right upper quadrant abdominal pain. She also reported weight loss of nine and a half kilos. She had been referred several times to hospital and received several courses of intravenous antibiotics with no improvement. Full blood count analysis showed a leucocyte count of 14.2 × 109/L with mild lymphocytosis (5.4 × 109/L) and normal haemoglobin and platelet counts. A blood film showed a population of small, mature appearing lymphocytes with coarse nuclear chromatin and a second population of small lymphocytes with convoluted nuclei (Figure 1). Figure 1: Peripheral blood smear, modified Wrights stain (original magnification ×1000) showing atypical lymphocytes with convoluted nuclei. Biochemistry showed slightly elevated alanine transaminase (57?U/L (0–50?U/L)) and alkaline
References
[1]
S. H. Swerdlow, E. Campo, N. L. Harris et al., WHO Classification of Tumours of Haematopoietic and Lymphoid Tissues, International Agency for Research on Cancer, Lyon, France, 4th edition, 2008.
[2]
M. Onciu, F. G. Behm, S. C. Raimondi et al., “ALK-positive anaplastic large cell lymphoma with leukemic peripheral blood involvement is a clinicopathologic entity with an unfavorable prognosis: report of three cases and review of the literature,” American Journal of Clinical Pathology, vol. 120, no. 4, pp. 617–625, 2003.
[3]
T. A. Summers Jr. and J. T. Moncur, “The small cell variant of anaplastic large cell lymphoma,” Archives of Pathology and Laboratory Medicine, vol. 134, no. 11, pp. 1706–1710, 2010.
[4]
J. Juco, J. T. Holden, K. P. Mann, L. G. Kelley, and S. Li, “Immunophenotypic analysis of anaplastic large cell lymphoma by flow cytometry,” American Journal of Clinical Pathology, vol. 119, no. 2, pp. 205–212, 2003.
[5]
C. Bayle, A. Charpentier, E. Duchayne et al., “Leukaemic presentation of small cell variant anaplastic large cell lymphoma: report of four cases,” British Journal of Haematology, vol. 104, no. 4, pp. 680–688, 1999.
[6]
M. M. Anderson, C. W. Ross, T. P. Singleton, S. Sheldon, and B. Schnitzer, “Ki-1 anaplastic large cell lymphoma with a prominent leukemic phase,” Human Pathology, vol. 27, no. 10, pp. 1093–1095, 1996.
[7]
M. C. Kinney, R. D. Collins, J. P. Greer, J. A. Whitlock, N. Sioutos, and M. E. Kadin, “A small-cell-predominant variant of primary Ki-1 (CD30)+ T-cell lymphoma,” American Journal of Surgical Pathology, vol. 17, no. 9, pp. 859–868, 1993.
[8]
D. Benharroch, Z. Meguerian-Bedoyan, L. Lamant et al., “ALK-positive lymphoma: a single disease with a broad spectrum of morphology,” Blood, vol. 91, no. 6, pp. 2076–2084, 1998.
[9]
H. Stein, H.-D. Foss, H. Durkop et al., “CD30+ anaplastic large cell lymphoma: a review of its histopathologic, genetic, and clinical features,” Blood, vol. 96, no. 12, pp. 3681–3695, 2000.
[10]
N. Villamor, M. Rozman, J. Esteve et al., “Anaplastic large-cell lymphoma with rapid evolution to leukemic phase,” Annals of Hematology, vol. 78, no. 10, pp. 478–482, 1999.
[11]
N. Awaya, S. Mori, H. Takeuchi et al., “CD30 and the NPM-ALK fusion protein (p80) are differentially expressed between peripheral blood and bone marrow in primary small cell variant of anaplastic large cell lymphoma,” American Journal of Hematology, vol. 69, no. 3, pp. 200–204, 2002.
[12]
B. Falini and M. P. Martelli, “Anaplastic large cell lymphoma: changes in the World Health Organization classification and perspectives for targeted therapy,” Haematologica, vol. 94, no. 7, pp. 897–900, 2009.