Primary cutaneous gamma/delta T-cell lymphoma (PCGDTCL); This literature-non-study case was reported in a literature article and describes the occurrence of CUTANEOUS T-CELL LYMPHOMA (Primary cutaneous gamma/delta T-cell lymphoma (PCGDTCL)) in a 79-year-old male patient who received mRNA-1273 (Moderna COVID-19 Vaccine) for COVID-19 prophylaxis.   LITERATURE REFERENCE:     No Medical History information was reported.   On an unknown date, the patient received third dose of mRNA-1273 (Moderna COVID-19 Vaccine) (unknown route) 1 dosage form. On an unknown date,  after starting mRNA-1273 (Moderna COVID-19 Vaccine), the patient experienced CUTANEOUS T-CELL LYMPHOMA (Primary cutaneous gamma/delta T-cell lymphoma (PCGDTCL)) (seriousness criteria hospitalization and medically significant). The patient was treated with DOXYCYCLINE for Cellulitis, at an unspecified dose and frequency and Radiotherapy for Cutaneous T-cell lymphoma. At the time of the report, CUTANEOUS T-CELL LYMPHOMA (Primary cutaneous gamma/delta T-cell lymphoma (PCGDTCL)) had resolved.      DIAGNOSTIC RESULTS (normal ranges are provided in parenthesis if available): On an unknown date, ALK gene rearrangement assay: Negative. On an unknown date, Biopsy: revealed a sparse perivascular but atypical lymphocytic infiltrate with a small population of lymphocytes expressing TCR delta.. On an unknown date, CD30 expression: Negative. On an unknown date, CD4 lymphocytes: Negative. On an unknown date, CD8 lymphocytes: Negative. On an unknown date, Dermatologic examination: Ulcerated plaque with surrounding erythema at the vaccine site on the left upper arm at initial presentation. Five months following initial presentation, dermatologic examination revealed a subtle pink patch without induration on the right upper arm. and On the left upper arm, there was a well-healed scar without palpable masses or lymphadenopathy five months following initial presentation.. On an unknown date, Epstein-Barr virus test: (Negative) In situ hybridization for Epstein-Barr virus was negative. On an unknown date, Histology: Histopathology reveals ulceration with a diffuse lymphoid infiltrate that replaces the dermis and subcutaneous fat. The lymphocytes are characterized by atypia and associated with numerous "bean bag" cells. Epidermotropism and folliculotropism could not be evaluated due to extensive ulceration. Angiotropism and angiodestruction were present. Lesional cells diffusely expressed CD3, granzyme B and T-cell receptor (TCR) delta. CD5, CD7, and TCR BetaF1 were negative. The lymphocytes are negative for TCR BetaF1 and positive for TCR Delta.. On an unknown date, Natural killer cell count: There was weak expression by CD56. On an unknown date, Physical examination: Clinical examination revealed no palpable lymphadenopathy. On an unknown date, Positron emission tomogram: Subsequent PET/CT scan revealed three hypermetabolic subcutaneous foci in the left upper extremity near the initial ulcer without nodal hypermetabolic activity. and Subsequent PET/CT scan showed no evidence of residual disease.. On an unknown date, T-cell receptor gene rearrangement test: were consistent with a clonal T-cell population. These findings were consistent with primary cutaneous gamma/delta T-cell lymphoma (PCGDTCL). and confirmed the presence of a clonal T-cell population identical to the original site..   For mRNA-1273 (Moderna COVID-19 Vaccine) (Unknown), the reporter did not provide any causality assessments.   Concomitant medications were not provided.  Patient received the Moderna COVID-19 vaccine booster in the left upper arm. Three days later, patient developed an ulcer at the vaccine site that progressed with surrounding erythema. Patient received the initial two doses of the vaccine nine and ten months prior in the same arm without complications. Patient was treated for cellulitis for three weeks without improvement. Due to clinical progression, patient was admitted for intravenous antibiotics. Skin debridement was performed due to eschar formation. Following debridement, the affected area on the arm improved with gradual healing and no residual lesion or masses.   Patient reported no fever, night sweats, low appetite, or weight loss. Patient remained healthy without systemic symptoms or worsening skin involvement despite no additional intervention.   Patient opted for conservative treatment given the unusually indolent nature of his condition and completed localized radiation therapy to both upper arms (39 Gy in 13 fractions). Patient remains well without evidence of recurrence eleven months after initial presentation.  Author stated that patient's presentation was unusual as it arose at the site of a COVID-19 vaccination several days after vaccination. Despite a second distant site of involvement, patient had a favorable disease course and continues to do well 11 months after initial presentation despite only receiving localized radiation therapy. Since this presentation and course are not typical of PCGDTCL, it is unclear if his lesions represent an indolent variant of PCGDTCL or other lymphoma with gamma/delta expression. It is unknown if the COVID-19 vaccine directly contributed to presentation or disease course.  Company Comment: This Literature case concerns a 79 year old male patient, with no relevant medical history reported,  who experienced the unexpected, serious (Hospitalization, medically significant) event of Cutaneous T-cell Lymphoma (Primary cutaneous gamma/delta T-cell lymphoma (PCGDTCL)) on an unspecified date after receiving the 3 dose of Moderna vaccine in the covid 19 vaccination series. Three days later, he developed an ulcer at the vaccine site that progressed with surrounding erythema. Dermatologic examination: Ulcerated plaque with surrounding erythema at the vaccine site on the left upper arm at initial presentation., Five months following initial presentation, there was a subtle pink patch without induration on the right upper arm and on the left upper arm, there was a well-healed scar without palpable masses or lymphadenopathy five months following initial presentation. Blood tests including ALK gene rearrangement assay, CD30 expression, CD4, CD8 Lymphocytes, Epstein-Barr virus test and Insitu hybridization for Epstein-Barr virus were negative. Biopsy revealed a sparse perivascular but atypical lymphocytic infiltrate with a small population of lymphocytes expressing TCR delta. Patient was treated with Doxycycline for cellulitis for three weeks without improvement. Due to clinical progression, patient was admitted for intravenous antibiotics. Skin debridement was performed due to eschar formation. The affected area on the arm improved with gradual healing and no residual lesion or masses. Localized radiation therapy to both upper arms (39 Gy in 13 fractions) was completed and Patient remained well without evidence of recurrence, eleven months after initial presentation. Patient reported no fever, night sweats, low appetite, or weight loss. Patient had previously received the initial two doses of covid 19 vaccine, nine and ten months prior, in the same arm without complications. The author's stated that, patient's presentation was unusual as it arose at the site of a COVID-19 vaccination several days after vaccination. Despite a second distant site of involvement, patient had a favorable disease course and continued to do well 11 months after initial presentation despite only receiving localized radiation therapy. Since this presentation and course were not typical of PCGDTCL, it is unclear if his lesions represent an indolent variant of PCGDTCL or other lymphoma with gamma/delta expression. It is unknown if the COVID-19 vaccine directly contributed to presentation or disease course. Concomitant medications were not provided. The event was reported as resolved. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.   Most recent FOLLOW-UP information incorporated above includes: On 22-Dec-2022: Live follow up received by safety on 22-Dec-2022 has email with full text article and contains significant information: Reporter information, literature information, laboratory details, product details, event details, seriousness and narrative were updated.; Sender's Comments: This Literature case concerns a 79 year old male patient, with no relevant medical history reported, who experienced the unexpected, serious (Hospitalization, medically significant) event of Cutaneous T-cell Lymphoma (Primary cutaneous gamma/delta T-cell lymphoma (PCGDTCL)) on an unspecified date after receiving the 3 dose of Moderna vaccine in the covid 19 vaccination series. Three days later, he developed an ulcer at the vaccine site that progressed with surrounding erythema. Dermatologic examination: Ulcerated plaque with surrounding erythema at the vaccine site on the left upper arm at initial presentation., Five months following initial presentation, there was a subtle pink patch without induration on the right upper arm and on the left upper arm, there was a well-healed scar without palpable masses or lymphadenopathy five months following initial presentation. Blood tests including ALK gene rearrangement assay, CD30 expression, CD4, CD8 Lymphocytes, Epstein-Barr virus test and Insitu hybridization for Epstein-Barr virus were negative. Biopsy revealed a sparse perivascular but atypical lymphocytic infiltrate with a small population of lymphocytes expressing TCR delta. Patient was treated with Doxycycline for cellulitis for three weeks without improvement. Due to clinical progression, patient was admitted for intravenous antibiotics. Skin debridement was performed due to eschar formation. The affected area on the arm improved with gradual healing and no residual lesion or masses. Localized radiation therapy to both upper arms (39 Gy in 13 fractions) was completed and Patient remained well without evidence of recurrence, eleven months after initial presentation. Patient reported no fever, night sweats, low appetite, or weight loss. Patient had previously received the initial two doses of covid 19 vaccine, nine and ten months prior, in the same arm without complications. The author's stated that, patient's presentation was unusual as it arose at the site of a COVID-19 vaccination several days after vaccination. Despite a second distant site of involvement, patient had a favorable disease course and continued to do well 11 months after initial presentation despite only receiving localized radiation therapy. Since this presentation and course were not typical of PCGDTCL, it is unclear if his lesions represent an indolent variant of PCGDTCL or other lymphoma with gamma/delta expression. It is unknown if the COVID-19 vaccine directly contributed to presentation or disease course. Concomitant medications were not provided. The event was reported as resolved. The benefit-risk relationship of mRNA-1273 Vaccine is not affected by this report.