Blue nevi are melanocytic tumors appearing as blue, gray, brown, or black nodules, often confused with pigmented nevi or melanoma. They include variations such as common blue nevus and cellular blue nevus, each with specific characteristics and histopathological features. Typically found on the skin, their presentation and diagnosis can be varied, with some exceptional forms noted in different locations.

1. BLUE NEVUS
SREEREMYA.S
ASSISTANT PROFESSOR
DEPT OF BIOTECHNOLOGY
SREE NARAYANA GURU COLLEGE

2. • Blue nevi can be described clinically as blue, gray,
brown, or black solitary nodules or Histologically,
they represent collections of melanocytes and
melanophages in the dermis. Blue nevus also
termed (nevus blau) was first studied by Tièche, a
student of Jadassohn, in 1906. That blue nevi are
not recognized more frequently may typically
result from their confusion with ordinary
pigmented nevi or because of the mistaken
diagnosis of malignant melanoma.

3. • Blue nevus (BN) and related entities are a
heterogeneous group of congenital and
acquired melanocytic tumors that
encompasses dendritic (“common”) blue
nevus (DBN), cellular blue nevus (CBN), and
variants, as atypical cellular blue nevus (ACBN)
and malignant BN/melanoma (Murali et al.,
2009) [1].

4. • They share many clinical and morphologic
characteristics including their blue tinctorial
properties; dermal proliferation of spindle,
fusiform or ovoid cells; melanin pigment
inside both the melanocytic tumor cells and
macrophages; and variably stromal fibrosis
and collagen amounts

5. • HISTOPATHOLOGY
• Blue nevi are generally seen on skin and rarely on
oral mucosa, vagina or uterine cervix types of
blue nevi are common BN. The histopathologic
picture in the ordinary BN is diagnostic. It is
featured by spindle-shaped, bipolar, dendritic
cells grouped in irregular masses in the lower two
thirds of the cutis and separated from the
overlying epidermis by normal cutis

6. • Distinguishing Characteristics of Blue Nevus
• Classic BN is a small (<1 cm), gray-blue or blue-
black macule, papule, or plaque generally located
on the head, neck, presacral region, or distal
extremities. Exceptional extracutaneous locations
have also been delineated. It is almost invariably
researched during the second decade of life;
most patients belong to phototypes III–IV. The
cellular variant is a much larger blue black
nodular lesion whose location is the gluteal
region.

7. • The scalp and the extremities are less commonly
affected. Unusual clinical features of blue nevi
include congenital, familial, eruptive, plaque-like,
targetoid, and linear forms (Causeret et al., 1977)
[12]. The term “agminated BN” has been availed
for multiple blue nevi sometimes arising within
amongolian spot. Generally, all lesions are
belonging to the BN family and it represents
demographic and clinical characteristics which
are similar to those of common and cellular blue
nevi. “

8. • Hypochromic” variants of blue nevi do not
seem to be “ancient” blue nevi because of the
young age of most of the patients. These
variants of BN are very rarely recognized as
such on clinical grounds: in fact, the paucity of
melanin often imparts a grayish or even a
grayish- brown color (Butler et al.,1967) [13].
Epithelioid BN also is similar to BN from a
clinical point of view, but is histopathologically
distinctive.

9. refernce
• S.sreeremya,Blue Nevus International
Journal of Molecular Biotechnology Vol. 4:
Issue 1