Dermatology: Practical and Conceptual Research Letter | Dermatol Pract Concept. 2024;14(2):e2024129 1 Granulomatous Dermatitis Characterized by the Manifestation of Tumor and Plaque Lesions Subsequent to Herpes Zoster: A Case Series Dilek Bayramgürler1, Abdullah Demirbaş1, Murat Durdu2, Göktuğ Eren Aslankoç1, Tuğrul Eruyar3, Cüyan Demirkesen3 1 Department of Dermatology, Faculty of Medicine, Kocaeli University, Kocaeli, Turkey 2 Department of Dermatology, Faculty of Medicine, Başkent University, Adana, Turkey 3 Department of Pathology, Faculty of Medicine, Kocaeli University, Kocaeli, Turkey Key words: Postherpetic isotopic response, Tumor, Granulomatous reaction Citation: Bayramgürler D, Demirbaş A, Durdu A, Aslankoç GE, Eruyar T, Demirkesen C. Granulomatous Dermatitis Characterized by the Manifestation of Tumor and Plaque Lesions Subsequent to Herpes Zoster: A Case Series. Dermatol Pract Concept. 2024;14(2):e2024129. DOI: https://doi.org/10.5826/dpc.1402a129 Accepted: December 14, 2023; Published: April 2024 Copyright: ©2024 Bayramgürler et al. This is an open-access article distributed under the terms of the Creative Commons Attribution- NonCommercial License (BY-NC-4.0), https://creativecommons.org/licenses/by-nc/4.0/, which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original authors and source are credited. Funding: None. Competing Interests: None. Authorship: All authors have contributed significantly to this publication. Corresponding Author: MD, Abdullah Demirbaş, Department of Dermatology, Faculty of Medicine, Kocaeli University, Kocaeli, Turkey. Phone number: +905464002546 E-mail: abdullah_demrba@yahoo.com Introduction Herpes zoster (HZ) is a painful vesicular dermatomal ex- anthem caused by the reactivation of the latent varicella zoster virus in cutaneous sensory nerves. It is more common in immunocompromised patients and can lead to compli- cations like postherpetic neuralgia and secondary bacterial infections [1]. Postherpetic isotopic response (PHIR) is a rare chronic cutaneous reaction that can cause new skin diseases independent of previous ones [2]. Herein, we report two cases of PHIR-granulomatous disease (GD) in patients with different hematological diseases. Case Presentations Case 1: An 87-year-old male patient with a history of chronic lymphocytic leukemia, benign prostatic hyperplasia, and hypertension presented with painless bruising and swell- ing on the inner side of his left thigh for nine months. The patient stated that he had an HZ infection 1.5 years ago, and the affected area matched the current lesion area. The lesion was a 10 x 10 cm tumor with a brown livid color and a pen- dulous appearance. A dermatological examination revealed a brown-purple flaccid tumor on the medial aspect of the left thigh along with keratotic plugs on a yellowish background 2 Research Letter | Dermatol Pract Concept. 2024;14(2):e2024129 (Figure 1, A and B). The differential diagnosis included B-cell lymphoma, anaplastic large cell lymphoma, granulomatous loose skin syndrome, and tuberculosis based on the clinical presentation. Histopathological examination of the lesion revealed well-formed granuloma structures, mononuclear inflammatory cell infiltration, and fragmented elastic fibers (Figure 1C). Immunohistochemical studies showed CD20+, CD2, CD3, CD5, CD7, CD8, and CD4+. The patient’s PPD Figure 1. (A) A 10x10 cm brown-livid tumoral lesion on the left medial thigh of an 87-year-old male patient (Case 1). (B) Dermoscopy showed keratotic plugs on yellowish background (black rings). (C) Histopathological examination revealed mononuclear inflammatory cell infiltration with granuloma structures localized in the papillary dermis, where epithelioid histiocytes form, destroying the follicle, and multinucleated giant histiocytes scattered around (H&E stain, ×100; black arrow) and a granuloma structure formed by epithelioid histio- cytes localized in the papillary dermis (H&E stain, ×200). (D) Regression of tumoral lesion after intralesional steroid therapy. Figure 2. (A) Erythematous papules and plaques on the posterior aspect of the right thigh of a 68-year-old male patient (Case 2). (B) Histopathological examination showed granuloma structure in the dermis and (C) multinuclear giant cells phagocytosing fragmented elastic fibers. (D) Improvement of granulomatous lesions with atrophic scar after topical corticosteroid therapy. (F) H&E stain, ×100. (G) H&E stain, ×1000. Research Letter | Dermatol Pract Concept. 2024;14(2):e2024129 3 was 0 mm, and the Quantiferon test was negative, as were the tuberculosis polymerase chain reaction and deep fungal culture. PHIR-GD was diagnosed. The patient received in- tralesional steroid injections once a month for four months, and after significant regression of the lesions, topical steroids were continued (Figure 1D). Case 2: A 68-year-old male patient with myelodysplastic syndrome presented with a painless rash on his right buttock and thigh for six months. He had had an HZ infection two years prior, which matched the current lesion area. Derma- tological examination revealed erythematous papules and plaques on the right gluteal area and posterior aspect of the thigh (Figure 2A). Histopathological examination revealed a compact hyperkeratosis layer, acanthosis in the epidermis, flattening of rete projections, scattered eosinophil exocyto- sis, vacuolization, focal subepidermal separation in the basal layer, and granulomatous lymphohistiocytic infiltration in the dermis. While collagen degeneration and mucin deposi- tion, which support interstitial granulomatous drug-related dermatitis, were not observed in this case, multinucleated giant cells that phagocytosed elastotic fibers were detected (Figure 2A and B). The patient was diagnosed with PHIR-GD and started on clobetasol propionate ointment, which re- solved within two months with atrophic scars (Figure 2D). Conclusions Wolf’s isotopic response is a phenomenon where a healed skin condition reappears at the same site, causing a new condition. The cause is unknown, but it is suggested to be an immunosuppressed region [1-3]. This area becomes susceptible to infections, tumors, and immune disorders. Chronic lymphedema, herpetic infections, vaccinations, and physical injuries can damage the cutaneous site, making it vulnerable. The most common isotopic response is PHIR, which is characterized by papules or plaques, patchy or nodular lesions, and hyperpigmentation [1-4]. Most cases have immunosuppressive and hematological malignancies, and both cases have hematological malignancies [1-5]. Top- ical steroids are commonly used in treating PHIR-GD cases [1-5], but no case has been treated with intralesional ste- roids. In conclusion, PHIR-GD can cause tumoral lesions, and intralesional corticosteroid therapy can be used for tumor management. References 1. Patil A, Goldust M, Wollina U. Herpes zoster: A Review of Clin- ical Manifestations and Management. Viruses. 2022;14(2):192. doi: 10.3390/v14020192. 2. Ruocco V, Ruocco E, Piccolo V, Brunetti G, Guerrera LP, Wolf R. The immunocompromised district in dermatology: A unifying pathogenic view of the regional immune dysregulation. Clin Dermatol. 2014;32(5):569-76. doi: 10.1016/j.clindermatol.2014 .04.004. 3. Yoon JH, Jang YJ, Park EJ, Kim KJ, Kim KH. A Case of Her- pes Zoster Granulomatous Dermatitis: Report of Wolf’s Isotopic Response. Ann Dermatol. 2021;33(2):186-189. doi: 10.5021 /ad.2021.33.2.186.  4. Munir S, Abu-Jubara D, Abu-Jubara M, Antypas C, Petro- Sakuma C. A New Skin Manifestation at the Site of a Pre- viously Healed Dermatosis: A Case of Wolf’s Isotopic Response. Cureus. 2020 ;12(11):e11381. doi: 10.7759/cureus.11381.  5. McCoy WH 4th, Otchere E, Musiek AC, Anadkat MJ. Granulo- matous dermatitis as a postherpetic isotopic response in immu- nocompromised patients: A report of 5 cases. JAAD Case Rep. 2018;4:752-60.