Cellular blue nevus - A challenging entity: Case report

Cellular blue nevus ISSN: 2394-0026 (P)Case Report ISSN: 2394-0034 (O)Cellular blue nevus - A challenging entity: Case reportSumalatha Kasturi1*, Sreenivas Vemula2, Santhosh Babu Rendla3, Narender Gajula4, Ravindra Thota51Assistant Professor, Department of Pathology, Chalmeda Anandrao Institute of Medical Sciences, Karimnagar, Telangana State, India2Professor, Department of Pathology, Chalmeda Anandrao Institute of Medical Sciences, Karimnagar, Telangana State, India3Associate Professor, Department of Radiology, Chalmeda Anandrao Institute of Medical Sciences, Karimnagar, Telangana State, India4Assistant Professor, Department of Dermatology, Chalmeda Anandrao Institute of Medical Sciences, Karimnagar, Telangana State, India5Professor, Department of Pathology, Chalmeda Anandrao Institute of Medical Sciences, Karimnagar, Telangana State, India *Corresponding author email: [email protected] to cite this article: Sumalatha Kasturi, Sreenivas Vemula, Santhosh Babu Rendla, NarenderGajula, Ravindra Thota. Cellular blue nevus - A challenging entity: Case report. IAIM, 2015; 2(2):129-132. Available online at www.iaimjournal.comReceived on: 08-01-2015 Accepted on: 16-01-2015AbstractBlue nevi can present clinically as blue, gray, brown, or black solitary nodules or plaques on the skin.Histologically, they represent collections of melanocytes and melanophages in the dermis. Wepresented here a case of a cellular blue nevus in a 20 years old man that presented as an enlargingblue-gray nodule on the right buttock. These cases can be challenging both clinically andhistologically because malignant melanoma or malignant transformation of a blue nevus could beconsidered.Key wordsCellular blue nevus, Buttock, Malignant melanoma.Introduction cellular blue nevus and combined nevus which may be present at birth but usually appearBlue nevi are usually seen on skin and rarely on around puberty. Common blue nevi can occuroral mucosa, vagina or uterine cervix [1]. Three on any site whereas cellular blue nevi are oftentypes of blue nevi are common blue nevus,International Archives of Integrated Medicine, Vol. 2, Issue 2, February, 2015. Page 129Copy right © 2015, IAIM, All Rights Reserved.

Cellular blue nevus ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)seen on dorsa of hands, feet, buttock or face [1, aberrant location of melanocytes. These dermal2]. Progressive growth is rare and rarely melanocytes absorb high wavelength light andmalignant transformation can occur in cellular reflect low wave length light, a phenomenonblue nevus. Blue nevi are seen as dome shaped; known as the Tyndall effect [1, 7]. Blue nevi aredark blue black 1-3 cm nodules. usually seen on skin and rarely on oral mucosa,Histopathologically, cellular blue nevi in addition vagina or uterine cervix [1]. .Blue nevi are oftento deeply pigmented dendritic melanocytes grouped together with hamartomatous dermalreveal cellular islands of closely aggregated, dendritic melanocytic proliferations such aslarge spindle shaped cells with ovoid nuclei and nevus of Ota, nevus of Ito and Mongolian spotabundant melanin in the cytoplasm. [3, 4]. Three types of blue nevi are common blue nevus, cellular blue nevus and combined nevusCase report which may be present at birth but usually appear around puberty.A 20 years old male patient presented with ablue black, painless nodule on the right buttock Photo - 1: External surface shows dome shapedsince 2 years. The patient denied any history of nodule. Cut section shows a well circumscribedtrauma. On examination, a dome shaped, non nodule in the dermis.fluctuant, non tender, firm, mobile nodule waspresent on right buttock. Excision biopsy was The cellular blue nevus was first described indone and sent for histopathological 1925 by Darier as a variant of melanoma butexamination. Gross examination showed a skin reclassified as a variant of blue nevus, whichcovered, dome shaped nodule of 4x3 cm. Skin typically follows a benign course [5]. Cellularover the nodule was smooth. Cut section blue nevi typically are larger than common bluerevealed a well circumscribed, horizontally oval, nevi, measuring 1-3 cm, while common blue nevisolid dark brown lesion in the dermis. (Photo - 1) typically measure less than 1 cm. Cellular blueMicroscopic examination revealed a highly nevi are more likely to be elevated, have acellular tumor spanning the entire dermis with a smoother surface, and may be more aggressivepushing border at the base. (Photo - 2) Spindle in their capacity for malignant transformation.shaped and dendritic melanocytes were Cellular and common blue nevi also may bearranged in fascicles and nodules admixed with differentiated by their location. Common bluethick collagen bundles. (Photo - 3) Mitotic nevi frequently occur on the dorsum of theactivity was low and there were no necrosis orsignificant pleomorphism. The pigment wasbleached upon reaction with hydrogen peroxide.(Photo - 4) So the final diagnosis was a benigncellular blue nevus.DiscussionBlue nevi are thought to result from the ectopicdeposition of melanocytes within the dermis.Normally in development, melanocytes migratefrom the neural crest to the epidermis.However, with blue nevi there appear to be apremature arrest of migration resulting in theInternational Archives of Integrated Medicine, Vol. 2, Issue 2, February, 2015. Page 130Copy right © 2015, IAIM, All Rights Reserved.

Cellular blue nevus ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)hands and feet, while cellular blue nevi most the epidermis. These lesions have an intactcommonly occur on the buttocks or sacro- epidermis and epidermo- dermal junction.coccygeal region but also can be seen on the Cellular blue nevi, however consist of foci ofscalp, face and feet. Our patient presented with oval, spindled, fusiform, or epithelioida 4 cm pigmented nodule on the right buttock melanocytes that occupy the deep dermis and[6]. extend along adnexal structures and neurovascular bundles into the subcutaneousPhoto - 2: Skin with circumscribed nodule in the tissue. The cells contain abundant paledermis. (H&E, 40X) cytoplasm containing little or no melanin [7]. Photo - 4: Bleach reaction revealed spindle cells with bland nuclear features. (H&E, 400X)Photo - 3: Intersecting bundles of pigmented Melanomas can rarely arise in the background ofmelanocytes admixed with collagen bundles. cellular blue nevi. These malignant blue nevi(H&E, 100X) typically raise clinical concerns because of their increasing size. Histologic evidence of malignantWhile the 3 clinically described variants of blue transformation is demonstrated by a sheet likenevi may be distinguished histologically, other growth pattern, necrosis, nuclearpathologic distinctions have been made among hyperchromasia, nuclear pleomorphism,these categories of blue nevi. Common blue nevi prominent nucleoli, excessive and atypicalare composed of pigmented dendritic mitotic activity and infiltrative borders.melanocytes and melanophages in the reticular Malignant blue nevi follow an aggressive coursedermis, positioned with their long axis parallel to and studies have documented mortality rates as high as 73% due to metastases. As a result, clinical guidelines recommend prompt excision of blue nevi to evaluate for malignant change in case of rapid growth, size greater than 2 cm or atypical clinical morphology. In our patient, the nodule was completely excised and no histological evidence ofInternational Archives of Integrated Medicine, Vol. 2, Issue 2, February, 2015. Page 131Copy right © 2015, IAIM, All Rights Reserved.

Cellular blue nevus ISSN: 2394-0026 (P) ISSN: 2394-0034 (O)malignant transformation was found. The 3. Murali R, Mc carthy SW, Scolyer RA. Bluepatient is doing well 2 years after the excision of nevi and related lesions: a reviewblue nevus. highlighting atypical and newly described variants, distinguishingConclusion features and diagnostic pitfalls. Adv Anat Pathol., 2009; 16(6): 365-382.Cases of cellular blue nevi can be challenging 4. Zembowicz A, Mihm MC. Dermalboth clinically and histologically because they dendritic melanocytic proliferations: Anmimic malignant melanoma or malignant update. Histopathology, 2004; 45(5):transformation of a blue nevus. Careful 433-451.histopathological examination is the mainstay of 5. Darier J. Le melanoma malindiagnosis in such cases. mesenchymatieu ou melanosarcoma. Bull Assoc Fr Cancer, 1925; 14: 221-249.References 6. Fuchs F, Guillot E, Salama S, Vige P, Coulomb LA, Raynal P. Giant congenital 1. David E, Elentitsa R. Benign pigmented scalp blue nevus, a neonatal case report. lesions and malignant melanoma In: Eur J Obstet Gynecol Repro Biol., 2007; Elder D, Elentitsa R, Jaworsky C, et al. 132(2): 243-244. eds. Lever’s Histopathology of skin. 7. Zembowciz A, Granter SR, Mc kee PH, et Philadelphia: Lippincott Raven, 1997; p. al. Amelanotic cellular blue nevus: 625-684. Clinicopathologic analysis of 20 cases. Am J Surg Pathol., 2002; 26: 1493-1500. 2. Causeret AS, Skowron F, Viallard AM, Balme B, Thomas L. Subungual blue nevus. J Am Acad Dermatol., 2003; 49(2): 310-312.Source of support: Nil Conflict of interest: None declared.International Archives of Integrated Medicine, Vol. 2, Issue 2, February, 2015. Page 132Copy right © 2015, IAIM, All Rights Reserved.