Transformation of T-Cell Acute Lymphoblastic Lymphoma to Peripheral T-Cell Lymphoma: A Report of Two Cases

Table 1

Patient 1 pathological findings, by site.

Site (days from original diagnosis)	Diagnosis	Morphology	IHC (T-cell population of interest)	Flow (T-cell population of interest)	Gene rearrangements		Peripheral blood CBC with 100-cell differential count (%)
Left iliac crest 0 days	T-cell ALL	Small- to medium-sized blast population comprising 95% of cells; marrow nearly 100% cellular	Positive: TdT, beta F1 Negative: TCRγ	Positive: CD3, CD4/CD8 dual positive, CD2, CD5 (d), CD7, and TDT (d) Negative: CD1a, CD34, CD117	TβA	257	WBC^a	18.7
					TβB	269	Hemoglobin^b	10.5
					TβC	182.9, 190.84	MCV^c	92.8
					TγA	190.94, 214.3	Platelets^a	211
					TγB	172.9	Lymphocytes	15
							Atypical lymphocytes	0
							Blasts	1
Left iliac crest 104 days	No evidence of malignancy	nc	np	nc	TβA	256	WBC^a	3.62
					TβB	126, 263.8	Hemoglobin^b	10.8
					TβC	190.63	MCV^c	92.8
					TγA	Germline	Platelets^a	334
					TγB	172.4	Lymphocytes	37
							Atypical lymphocytes	0
							Blasts	0
Cerebrospinal fluid 120 days	T-cell ALL	Large granular lymphocyte-like cells with condensed chromatin, inconspicuous nucleoli, eccentric nuclei, and moderate pale blue cytoplasm with prominent azurophilic granules	np	Positive: CD3c, CD7, CD8, CD45 (b), CD4 equivocal Negative: CD3, TdT, CD34	np		WBC^a	2.44
							Hemoglobin^b	9.5
							MCV^c	88.3
							Platelets^a	104
							Lymphocytes	34.4
							Atypical lymphocytes	0
							Blasts	0
Right iliac crest 124 days	γδ PTCL	Atypical lymphohistiocytic T-cell infiltrate with granulomas; large mononuclear lymphocytes with round to irregular nuclear contours and moderate eccentric light blue pale cytoplasm and cytoplasmic granules	Positive: CD2, CD3 (>50%), CD5, CD7 (f), CD8, CD56, perforin, TIA, CD4 (equivocal) Negative: TdT, CD117, CD68, CD34, CD1a, CD99, granzyme-B, CD30, CD57, CD25, ISH EBER	Positive: CD3, CD3c, CD5, CD7, CD4 (d), CD8 (d), CD45 Negative: TdT, CD34, CD56	TβA	275	WBC^a	2.56
					TβB	126, 258, 263.8	Hemoglobin^b	8.7
					TβC	182.92, 190.63	MCV^c	88.1
					TγA	214.13	Platelets^a	76
					TγB	172.48	Lymphocytes	28.9
							Atypical lymphocytes	0
							Blasts	0
Skin, right arm 125 days	γδ PTCL	Atypical lymphoid cells	Positive: CD2, CD3, CD5, CD4, CD8, CD56, TIA, CD99 (d), granzyme-B, TCRγ Negative: CD7, TdT, CD34, CD1a	nd	np		WBC^a	2.61
							Hemoglobin^b	9.8
							MCV^c	87.9
							Platelets^a	98
							Lymphocytes	32.2
							Atypical lymphocytes	0
							Blasts	0
Skin, right flank 189 days	γδ PTCL	Atypical lymphocytic infiltrate comprised of large pleomorphic with round to irregular nuclear contours and ample cytoplasm with prominent nucleoli and elevated N:C ratio	Positive: CD3, CD4, CD8, TCRγ, CD56 Negative: TdT, Beta F1, CD20	Positive: CD3, CD5, CD4/CD8 dual positive, CD45, CD56 Negative: CD7 (partial loss)	np		WBC^a	9.1
							Hemoglobin^b	10.9
							MCV^c	95.8
							Platelets^a	58
							Lymphocytes	8
							Atypical lymphocytes	0
							Blast	0

Note: (b) bright; (d) dim; (f) focal; (s) positive in subset. +/− equivocal; nc, noncontributory; nd, nondiagnostic due to insufficient specimen; np, not performed. ^aIn k/μL; ^bin g/dL; ^cin fL. Manual differential used when available; otherwise, automated impedance counts were utilized.