To the editor:
Granular cell tumor is usually a benign neoplasm of Schwann cell origin, first described by Abrikossof in 1926.1 It is a rare entity, which compromises 5% of all soft-tissue tumors.2 Granular cell tumor is more common among women during the fourth–sixth decades of life, often of dark skin color,3 and is rarely seen in children.4 The frequently involved sites include the head and neck area and tongue, but viscera may be also involved.5 The etiopathogenesis of granular cell tumor is obscure, but there are 2 case reports of granular cell tumors, which appeared at sites of previous trauma or manipulation.6,7 The first was a 29-year-old woman with a granular cell tumor located at the region of episiotomy scar,6 and the second was a 14-year-old girl with granular cell tumor, which appeared on a BCG vaccination scar.7 We report a case of granular cell tumor in a young girl that also appeared on a vaccination site, 2 weeks after vaccination.
An 8-year-old girl presented to our clinic with 14-month history of an itchy nodule on her right upper arm. She had no significant medical history, and her growth and development were within the normal limits. The nodule appeared at a site of vaccination for tetanus-diphtheria-acellular pertussis (TDaP), inactivated polio (IPV), and influenza vaccines, which were preformed 2 weeks before. A single 2-cm pinkish nodule with hyperkeratotic center was noticed on the extensor part of her arm (Fig. 1). A 4-mm punch biopsy was obtained 1.5 years later. The pathological examination revealed an uninvolved epidermis. In the dermis, there was a dense infiltrate of cells with small regular nuclei and ample granular cytoplasm. PAS, S100, and CD68 stains were positive, as in granular cell tumor (Fig. 2). The nodule was fully excised and did not recur for 6 months since.
Granular cell tumor is usually a benign lesion as in our patient. The percentage of malignant granular cell tumors is 0.5%–2%.8 Large lesions, rapid growth, and histopathologically, necrosis, spindling, vesicular nuclei with large nucleoli, increased mitotic activity, high nuclear to cytoplasmic ratio, and pleomorphism are indicators of malignancy.9,10 Vaccination may induce pseudolymphoma in the skin,11 but in granular cell tumor, it is almost “unheard of.” In a previous case from India, granular cell tumor appeared on a BCG vaccination scar, but the time elapsed between the vaccination and appearance of the tumor was not specified.7 In our case, it appeared clinically 2 weeks after vaccination, although the biopsy was preformed 1.5 years later, which supports a causal relationship. Because it was also described in an episiotomy scar,6 we suggest that granular cell tumor in skin may be induced by skin trauma.
1. Abrikosoff A. Uber Myome, ausgehend von der quergestreiften willkurlichen Muskular. Virchw Arch Path Anat. 1926;260:215–233.
2. Gunduz O, Erkin G, Bilezkci B, et al. Slowly growing nodule on the trunk: cutaneous granular cell tumor. Dermatopathol. 2016;3:23–27.
3. Hatta J, Yanagihara M, Hasei M, et al. Case of multiple cutaneous granular cell tumors. J Dermatol. 2009;36:504–507.
4. Olayiwola O, Hook K, Miiler D, et al. Cutaneous granular cell tumors in children: case series and review of literature. Pediatr Dermatol. 2017;34:e187–e190.
5. Daulatabd D, Grover C, Tanveer N, et al. Granular cell tumor in a child: an uncommon cutaneous presentation. Indian Dermatol Online. 2016;7:390–392.
6. Murica JM, Laparte IC, Baldonado C. Case report granular cell tumor of vulva on episiotomy scar. Gynecol Oncol. 1994;53:248–250.
7. Bandyopadhyay D, Sen S, Bandyopadhyay JP. Granular cell tumor on vaccination scar in a young girl. Indian J Dermatol. 2006;51:196–197.
8. Requena L, Kutzner H. Cutaneous Soft Tissue Tumors. Philadelphia, PA: Wolters Kluwer; 2015:755–762.
9. Liu TT, Han Y, Zheng S, et al. En-hua wang: primary cutaneous malignant granular cell tumor: a case report in China and review of literature. Diagn Pathol. 2015;10:113.
10. Famburg-Smith JC, Meis-Kindblom JM, Fante R, et al. Malignant granular tumor of soft tissue: diagnostic criteria and clinicopathologic correlation. Am J Surg Pathol. 1998;22:779–794.
11. Cerroni L, Borroni RG, Massone C, et al: Cutaneous B cell lymphoma at the site of vaccination. Am J Dermatopathol. 2007;29:538–542.