Apo D

Apo D is a 33 kDa glycoprotein component of plasma high-density lipoprotein. Its gene is at 3q26.2: it is not involved in the t(17;22) translocation of dermatofibrosarcoma protuberans.

Immunohistochemical expression

Soft tissue tumours1:

		weak positivity	strong positivity
	Dermatofibrosarcoma protuberans	2/10	7/10
	Plaque stage dermatofibrosarcoma protuberans	3/3
	Myxoid dermatofibrosarcoma protuberans	1/1
	Dermatofibrosarcoma protuberans with sarcomatous transformation	3/6
	Bednar tumour	3/3
	Giant cell fibroblastoma	2/3
	Usual fibrous histiocytoma	0/16
	Angiomatoid fibrous histiocytoma	0/3
	Epithelioid fibrous histiocytoma	0/2
	Plexiform fibrous histiocytoma	0/2
	Atypical fibrous histiocytoma	0/4
	Aneurysmal fibrous histiocytoma	0/1
	Alveolar soft part sarcoma	0/2	2/2
	Angiosarcoma	4/14	3/14
	Atypical lipomatous tumour	8/34	2/34
	Carcinosarcoma	1/7	0/7
	Endometrial stromal sarcoma	0/9	2/9
	Eosinophilic granuloma	1/1	0/1
	Ewing's sarcoma/PNET	2/10	1/10
	Fibromatosis	1/18	0/18
	Fibroxanthoma	3/4	0/4
	Glomus tumour	0/5	3/5
	Granular cell tumour	4/11	4/11
	Haemangioblastoma	3/10	0/10
	Inflammatory pseudotumour	1/2	0/2
	Leiomyosarcoma	4/37	0/37
	Lymphangioma	1/2	0/2
	Malignant fibrous histiocytoma	19/53	1/53
	Osteosarcoma	2/14	1/14
	Paraganglioma	1/1	0/1
	Neurofibroma	6/8
	Peripheral nerve sheath tumour, benign	0/3	1/3
	Peripheral nerve sheath tumour, malignant	1/5	2/5
	Rhabdomyoma	1/1	0/1
	Rhabdomyosarcoma	1/13	1/13
	Solitary fibrous tumour	4/11	0/11
	Synovial sarcoma	4/56	0/56
	Tenosynovial giant cell tumour	8/9	1/9
	Angiomyxoma	0/1
	Chondrosarcoma	0/5
	Clear cell sarcoma	0/3
	Desmoplastic small round cell tumour	0/4
	Elastofibroma	0/1
	Embryonal sarcoma	0/1
	Epithelioid sarcoma	0/2
	Fasciitis	0/7
	Fibroma/fibroblastoma	0/3
	Fibromyxoid sarcoma	0/1
	Fibrosarcoma	0/4
	GIST	0/36
	Glomangioma	0/4
	Haemangioendothelioma	0/10
	Haemangioma	0/2
	Haemangiopericytoma	0/1
	Hibernoma	0/2
	Kaposi's sarcoma	0/3
	Leiomyoma	0/8
	Lipoblastomatosis	0/3
	Masson's lesion	0/1
	Myofibrosarcoma	0/1
	Myxofibrosarcoma	0/1
	Myxoma	0/8
	Neuroblastoma	0/1
Osteosarcoma	0/14
Rosai-Dorfmann disease	0/1
Sarcoma NOS	0/10

Histiocyte-like cells within various tumours may be positive.

CNS tumours2:

	Pilocytic astrocytoma	10/13
	infiltrating astrocytomas	0/21
	gangliogliomas	9/14
	subependymal giant cell astrocytomas	4/5
	pleomorphic xanthoastrocytomas	1/1

Apo D expression may be a good prognostic indicator in breast4 and ovarian3 carcinomas.

Diagnostic utility

Differentiation of dermatofibrosarcoma protuberans (positive) from fibrous histiocytoma (negative)1.

Differentiation of pilocytic astrocytoma (positive) from infiltrating astrocytoma (negative)2.

References

1West, R. B., J. Harvell, et al. (2004). "Apo D in soft tissue tumors: a novel marker for dermatofibrosarcoma protuberans." Am J Surg Pathol 28(8): 1063-9. Note: all TMA immunostain results are available on line.

2Hunter, S., A. Young, et al. (2002). "Differential expression between pilocytic and anaplastic astrocytomas: identification of apolipoprotein D as a marker for low-grade, non-infiltrating primary CNS neoplasms." J Neuropathol Exp Neurol 61(3): 275-81.

3Vazquez, J., L. Gonzalez, et al. (2000). "Expression and clinical significance of apolipoprotein D in epithelial ovarian carcinomas." Gynecol Oncol 76(3): 340-7.

4Diez-Itza, I., F. Vizoso, et al. (1994). "Expression and prognostic significance of apolipoprotein D in breast cancer." Am J Pathol 144(2): 310-20.

This page last revised 11.9.2004.