Stains & CD markers
HMB45
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: HMB45
HMB45
Author: Nat Pernick, M.D.
Last author update: 1 October 2012
Last staff update: 1 September 2023
Copyright: 2002-2023, PathologyOutlines.com, Inc.
PubMed Search: HMB45
Table of Contents
Definition / general | Uses by pathologists | Microscopic (histologic) images | Cytology images | Positive staining - normal | Positive staining - disease | Negative stainingCite this page: Pernick N. HMB45. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/stainsHMB45.html. Accessed September 30th, 2023.
Definition / general
- Human Melanoma Black, discovered in 1986 (Am J Pathol 1986;123:195)
- Monoclonal antibody originally identified from melanoma abstract, recognizes melanosomal glycoprotein gp100 (Pmel17)
- Membrane protein required to form melanosomal fibrils, facilitates maturation of stage I pre-melanosomes to stage II
- Identifies oncofetal glycoconjugate associated with immature melanosomes and probably related to the tyrosinase enzymatic system (J Histochem Cytochem 1992;40:207)
Uses by pathologists
- Common marker to confirm melanoma (invasive melanomas with paradoxical maturation show at least focal deep HMB45 reactivity, in contrast to nevi, which are negative in deep dermis)
- Evaluating sentinel lymph nodes for melanoma (Am J Surg Pathol 2001;25:1039)
- Diagnosis (or ruling out diagnosis) of perivascular epithelioid cell tumors (angiomyolipoma, lymphangioleiomyomatoisis, PEComa, clear cell "sugar" tumor)
Microscopic (histologic) images
Contributed by Jijgee Munkhdelger, M.D., Ph.D., Andrey Bychkov, M.D., Ph.D. and Cases #195, #220, #32 and #109
Cutaneous melanoma, HMB45
Bladder, paraganglioma
Kidney, angiomyolipoma
Kidney, atypical epithelioid angiomyolipoma
Uterus, melanoma
Images hosted on other servers:
Esophagus, melanoma
Kidney, angiomyolipoma
Lung, clear cell "sugar" tumor
Perivascular epithelioid cell tumors
Skin, melanoma
Skin, nevi and melanomas
Cytology images
Images hosted on other servers:
Thyroid, metastatic melanoma
Positive staining - normal
- Lymph nodes: scattered mononuclear cells
- Skin: junctional melanocytes, activated melanocytes
Positive staining - disease
- Skin and other sites: melanoma (85-90%, see exceptions under Negative staining)
- Also blue nevus, Spitz nevus (Spitz nevi may be HMB45- at other sites)
- Nevus cells may be HMB45+ in intraepidermal and superficial dermal component
- Nevus cells may also have weak nuclear staining that is overwhelmed by hematoxylin and usually not seen (Mod Pathol 2008;21:1121)
- Angiomyolipoma (various sites, usually negative in nasal cavity)
- Clear cell sarcoma of soft tissue (Am J Surg Pathol 2008;32:452)
- Clear cell "sugar" tumor (Am J Surg Pathol 2002;26:670)
- Epithelioid sarcoma (occasional)
- Kidney: t(6;11)(p21;q12) renal cell carcinoma (Hum Pathol 2012;43:726)
- Lymphangioleiomyomatosis (also stains nonproliferative cells)
- Melanocytosis
- PEComa (Am J Surg Pathol 2005;29:1558)
- Pheochromocytoma (30%, Arch Pathol Lab Med 1992;116:151)
- Pigmented neural tumors (some), including some nerve sheath tumors, some neurofibromas (Hum Pathol 2005;36:871), pigmented neuroectodermal tumor of infancy
- Tuberous sclerosis complex components
Negative staining
- Adult / resting melanocytes
- Some melanomas: desmoplastic, oral mucosal, spindle cell (but 50% of HMB45 negative melanoma cells have premelanosomes on EM)
- Atypical fibroxanthoma
- Epithelioid malignant peripheral nerve sheath tumors
- Leiomyosarcoma, liposarcoma
- Paget disease of breast, scrotum, vulva
- Pigmented dermatofibrosarcoma protuberans, pigmented epithelioid melanocytoma
- Uterine tumors resembling ovarian sex cord tumors (Am J Surg Pathol 2010;34:1749)
