The "sign of groove", a new cutaneous sign of internal malignancy.

A 36-year-old young male with multiple heterosexual contacts presented with bilateral inguinal bubo and the classical "sign of groove". A diagnosis of lymphogranuloma venereum (LGV) was made and a three-week course of doxycycline was given. Lack of response prompted us to investigate further. A biopsy of the bubo was consistent with non-Hodgkin's lymphoma (NHL). Immunohistochemistry of the lymph node done at the Regional Cancer Center (RCC), Trivandrum, confirmed the diagnosis as NHL of diffuse large B-cell type. The second patient, a 32-year-old male with two unprotected heterosexual contacts presented with a left-sided inguinal bubo of six weeks duration. An empirical course of doxycycline was given even though investigations did not reveal any STI. Lack of response prompted us to do a lymph node biopsy, which was consistent with NHL, which later with immunohistochemistry was confirmed as NHL, diffuse large cell type. We are reporting here that the "sign of groove" is not specific for LGV as thought earlier, but can occur in NHL also.